Senior Associate Editors · 2 3 Editorial Advisors Essam Osman, BDS, MSD, Ph.D. Vice-President for...

1

Editors-in-SubchiefMichel Goldberg, Chir. Dent., Dr. Sc. Odont., D. Sc., PU,Emeritus Professor, Saints-Pères Biomedical College, INSERM/Unité 747-Equipe 5, Paris Descartes University, Paris, [email protected]

Elie M. Ferneini, B.Sc., MS Health Sciences, DMD,MD, MHS, MBA/HCM, FACS, FACDAssistant Clinical Professor, Oral and Maxillofacial Surgery Division, Department of Craniofacial Sciences, University of ConnecticutSchool of Dental Medicine, Farmington, Connecticut, USAEditor-in-Chief, American Journal of Cosmetic [email protected]

Josette Camilleri, B.Ch.D., M.Phil., Ph.D., FADM, FIMMM, FHEAProfessor of Restorative Dentistry and Endodontics, School of Dentistry, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, England, [email protected]

Hani F. Ounsi, Dr. Chir. Dent., DES Endo.,M.Sc. Dental Mat., DEA Oral Biol., FICD, Ph.D.,Assistant Professor, Department of Endodontics, Lebanese University, Faculty of Dental Medicine, Beirut,Visiting Professor, Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Siena, [email protected]

Tony Daher, Dr. Chir. Dent., CES Fixed Prostho.,CES Remov. Prostho., PG Cert. Prostho., MS (Education), FACP, FICP, FICD, MAO, M. Pierre Fauchard Academy,Diplomate, American Board of Prosthodontics,Co-Director, Global Dental Implant Academy - GDIA, La Palma, California, USA, and Visiting Clinical Professor of Prosthodontics, Saint-Joseph University Faculty of Dental Medicine, Beirut, [email protected]

Marcel Noujeim, BDS, DESS Oral Biol., DESS OralRadiol., MS (Oral/Max.Fac. Radiol.),Diplomate, American Board of Oral/MaxillofacialRadiology,Associate Professor, Department of Comprehensive Dentistry,Director of Oral and Maxillofacial Radiology Postgraduate Program,University of Texas Health Science Center at San Antonio -UTHSCSA, [email protected]

Tara Renton, BDS, M. Dent. Sc., FRACDS,FDSRCS (Engl.), Ph.D., ILTM, FHEA,Consultant Oral Surgeon, Professor and Head, Department of OralSurgery, King’s College London -KCL- Dental Institute, London, UK,[email protected]

Karine Feghali, BDS, DESS Perio., Ph.D.,Associate Professor, Department of Periodontics,Research Scientist, Oral Ecology Research Group (GREB),Laval University, Faculty of Dental Medicine, Quebec City, [email protected]

Editor-in-ChiefZiad E.F. Noujeim, Dr. Chir. Dent., CES Oral Biol., CES Surg. Dent., Dipl. Oral Pathol., DU Cell Therapy, DIU Anti-Aging Medicine, DU Oral Dermatology, Diplomate, European Board of Oral Surgery,Fellow, American College of Oral and Maxillofacial Surgery, International College of Dentists,Senior Lecturer and Postgraduate Tutor, Departments of Oral and Maxillofacial Surgery, Oral Medicine, and Basic Science,Former Director, Oral Pathology and Oral Surgery Postgraduate Programs, Former Chairperson of Research Department, Lebanese University, Faculty of Dental Medicine, Beirut, Atending Oral Surgeon, Baabda University Hospital,Lebanese Army Central Hospital and Lebanese Ministry of Defense Infirmary, Lebanon,Scientific Chairperson, Lebanese Society of Oral Surgery,Former Scientific Chairperson, Lebanese Dental Association, Section Editor, Annals of Maxillofacial Surgery - [email protected]

Ziad Salameh, Dr. Chir. Dent., DES Prostho., M.Sc.,Ph.D., HDR, FICD,Chairperson, Department of Research,Professor, Departments of Prosthodontics and Research, Lebanese University, Faculty of Dental Medicine, Beirut,Adjunct Associate Professor, Center for Craniofacial Regeneration,University of Pittsburgh, Pittsburgh, [email protected]@drziadsalameh.com

Charles Sfeir, Dr. Chir. Dent., Cert. Perio., MS, Ph.D.,Associate Dean for Research and Associate Professor, Departments of Oral Biology and Periodontics, and Founding Director, Center for Craniofacial Regeneration, University of Pittsburgh, School of Dental Medicine, Pittsburgh, Pennsylvania, USA [email protected]

Assem Soueidan, Dr. Chir. Dent., CES Perio.,DU Perio., DU Oral Rehab./Implant., DU OralDermatology, DEA, Dr. Univ., HDR, PU, PH,First Vice-Dean and Director of Clinical Investigation Unit, Professor and Chairperson, Department of Periodontology,Nantes University, Faculty of Dental Surgery, Nantes, [email protected]

Sami Mouwakdié, Dr. Chir. Dent., DU Perio.,DU Implant., DEA Génie Biologique, MBA,Assistant Professor, Department of Periodontology,Lebanese University, Faculty of Dental Medicine, Beirut,[email protected]

Fadl Khaled, BDS, CES Endo., DES Endo.,Adjunct Clinical Assistant Professor, Department of RestorativeSciences, Beirut Arab University, Faculty of Dentistry,Chief of Clinical Services, Department of Endodontics,Lebanese University, Faculty of Dental Medicine, [email protected]

Senior Associate Editors

Journal of the Lebanese Dental AssociationVolume 52 - Nº 1 - January-June 2017

32

Editorial AdvisorsEssam Osman, BDS, MSD, Ph.D.Vice-President for Medical Sciences, Beirut Arab University,Dean, Faculty of Dentistry,Chairperson, Departments of Restorative Sciences and OralSurgical Sciences, and Director, Division of Dental Biomaterials,Professor of Dental Materials, Faculty of Dentistry, [email protected]@bau.edu.lb

Nadim Z. Baba, DMD, MSD, FICD, FACP, Diplomate, American Board of Prosthodontics,Professor, Department of Restorative Dentistry, Director, Hugh Love Center for Research and Education in Technology, Loma Linda University, School of Dentistry, Loma Linda, California, USAAssociate Editor, Journal of Dental Traumatology, Director, Pacific American College of Prosthodontists,[email protected]

Maria E. Saadeh, BDS, MS (Human Morphology),Residency Orthod. AUB, Ph.DClinical Associate, Division of Orthodontics and DentofacialOrthopedics, American University of Beirut Medical Center,Lecturer, Department of Orthodontics,Lebanese University, Faculty of Dental Medicine, Beirut,[email protected]

André Assaf, BDS, CES Dent. Mat., CES FixedProstho., CES Remov. Prostho., DU Occlusodont.,DU Implant., DU Med. CommunicationAdjunct Clinical Associate Professor, Department of RestorativeSciences, Beirut Arab University, Faculty of Dentistry, BeirutSenior Lecturer, Department of Prosthodontics,Lebanese University, Faculty of Dental Medicine, Beirut, President, Lebanese Society of Prosthodontics,[email protected]

Leila Chahine, DMD, FAADSM,Diplomate, American Board of Dental Sleep Medicine,Dental Staff, Danbury Hospital, Western Connecticut HealthNetwork, Connecticut, [email protected]

Biostatistics and Epidemiology ConsultantsM Fouad Ziadé, Ph.D Biostat., C. Stat., FRSS, MASA,MIEAAssociate Professor, Lebanese University, Faculty of PublicHealth, Beirut/Tripoli, [email protected] / [email protected]

Nada E. El-Osta, DCD, DES Prostho., MS (Biol. Med.Sc.), DIU Biostat., DU Forensic ScienceConsultant in Biostatitics / Epidemiology,Saint-Joseph University, Faculties of Medicine and DentalMedicine, Beirut, [email protected] / [email protected]

Antoine Berbéri, BDS, MS, DU Perio,CES Odont. Chir., Dr. Univ., HDR, FICD,Diplomate, European Board of Oral Surgery,Professor and Former Chairperson,Department of Oral and Maxillofacial Surgery,Lebanese University, Faculty of Dental Medicine, Beirut,Research Scientist, Doctoral School of Sciences and Technology,Lebanese University, Beirut,[email protected]

Joseph Bouserhal, Dr. Chir. Dent., Specialist Ortho., DURCO, Ling. Ortho. Dip., Dr. Sc. Dent., MWFO, MAAO,Professor and Former Chairperson, Department of Orthodontics, Saint-Joseph University Faculty of Dental Medicine, Beirut, Adjunct Clinical Professor of Orthodontics, Boston University Henry M. Goldman School of Dental Medicine, Boston, USAPast President, Lebanese Orthodontic Society, Beirut, Lebanon,Instructor, Tweed Foundation for Orthodontic Research, USA,Visiting Professor in Orthodontics, Beirut Arab University, Universities of Paris V and VII (France), Aristotle University of Thessaloniki (Greece), and Paul Sabatier University of Toulouse (France)[email protected]

Georges Tawil, Dr. Chir. Dent., DDS, CES Odont.Chir., CES Perio., Dr.Sc.Odont., FICD, FACDFormer Professor and Chairperson, Department of Periodontology, Saint-Joseph University, Faculty of Dental Medicine, Beirut, Lebanon,Editorial Consultant, International Journal of Oral andMaxillofacial Implants, Clinical Oral Implant [email protected]

Ghassan Yared, DCD, DSO, FRCD (Can.), MRCDSOFormer Associate Professor, Department of Endodontics, andformer Director of Endodontics undergraduate program,University of Toronto, Faculty of Dentistry, Toronto, [email protected]

Dina Debaybo, Dr. Chir. Dent., CAGS, M.Sc.D.,Diplomate, American Board of Pediatric Dentistry,Clinical Associate Professor of Pediatric Dentistry,European University College, Dubai, [email protected]

Nabil Tabbara, DMD, FAAFO, FAACPAdjunct Clinical Professor, University of Western Ontario, Schulich, Department of Dentistry, School of Medicine and Dentistry, London, Ontario, [email protected] / [email protected]

Sukumaran Anil, BDS, MDS, Ph.D., FICD, FPFAProfessor and Consultant, Division of Periodontics, King SaudUniversity, College of Dentistry, Riyadh, KSA,[email protected]

Antoine F Saadé, DCD, CES Orthod., Du Orthod., CECSMOFormer Chairperson, Senior Lecturer, and Postgraduate Tutor, Department of Orthodontics and Dentofacial Orthopedics, Lebanese University, Faculty of Dental Medicine, Beirut,[email protected]

Editors EmeritiProfessor Philippe E. Aramouni, DCD, DEA, CAGS Prostho., M.Sc.D., FICDProfessor Nadim Z. Baba, DMD, MSD, FICD, FACP, Dipl. ABPMichel Salameh, DCD, CES Pediat. Dent., MIADP, MIADH, MSFOPAssistant Professor Georges Aoun, BDS, DES Oral Biol., DES Prostho., DSOAssociate Professor Antoine Cassia, DCD, CES Oral Biol. Bucc., CES Surg. Dent., DU Maxillofacial Prostho., DSOProfessor Levon Naltchayan, DCD, CES Prostho.Pierre Souaid, DCD

Associate Editors

Manuscript Editor

Joseph J. Massaad, DDS, MAGD, FACD, FICD, MIA Dent. Fac. Esth., M. Pierre Fauchard Academy,Clinical Associate Professor of Prosthodontics, University of Tennessee Health Science Center -UTHSC- College of Dentistry, Memphis, Tennessee, and, Adjunct Associate Professor, Department of Restorative Dentistry, Loma Linda University School of Dentistry, Loma Linda, California, [email protected]

Radhouane Dallel, Dr. Chir. Dent., Dr. Univ., HDR, PU, PH,Senior Scientist and Director, Neurobiology of Trigeminal Pain/Migraine Laboratory, NEURO-DOL, INSERM/UdA, U1107,Professor, Clermont 1 University, Faculty of Dental Surgery,Clermont-Ferrand, [email protected]@u-clermont1.fr

Zeina A.K. Majzoub, Dr. Chir. Dent., DMD, Dott. Odont.,CAGS, M.Sc.D,Professor of Periodontology and Research and FormerChairperson, Department of Research, Lebanese University,Faculty of Dental Medicine, Beirut,Former Professor of Periodontology and Research, University ofPadova, Institute of Clinical Dentistry, Padova, [email protected]

Pascale Habre Hallage, Dr. Chir. Dent., CES Oral Biol.,CES Fixed Prostho., DUICP, MSBM, DEA Neurosc.,Dr. Biomed. Sc.,Assistant Professor and Director of Postgraduate Program,Department of Fixed Prosthodontics and Occlusion,Saint-Joseph University, Faculty of Dental Medicine,Beirut, [email protected]@usj.edu.lb

Roula Abiad, BDS, MS Endo., Dr. Dent. Sc.,Assistant Dean, Assistant Professor of Endodontics,Director, Division of Endodontics,Beirut Arab University, Faculty of Dentistry, Beirut, [email protected]@gmail.com

Maroun F. Dagher, Dr. Chir. Dent., CAGS Perio.,M.Sc.D. Oral Biol., MS Research, MAAP, MAO, MIADR,Diplomate, American Board of Periodontology,Senior Lecturer and Clinical Tutor, Department of Periodontology,Saint-Joseph University, Faculty of Dental Medicine,Beirut, [email protected]@aol.com

Zoubeida Yahfoufi Al Hage, DDS, Dr. Dentistry, FITI,Assistant Professor, Department of Periodontology, Lebanese University, Faculty of Dental Medicine, Beirut, [email protected]

Jaime S. Brahim, DDS, MS, FACOMS, FAAOMS,Diplomate, American Board of Oral and MaxillofacialSurgery, American Board of Oral Medicine,Clinical Professor, Department of Oral and Maxillofacial Surgery,Director, Clinical Research Unit and Undergraduate Program, University of Maryland School of Dentistry, Baltimore, Maryland,Former Senior Oral and Maxillofacial Surgeon, National Institutesof Health-NIH, Bethesda, Maryland, [email protected]

Mary Ann Jabra-Rizk, Ph.DAssociate Professor, Department of Oncology and DiagnosticSciences, University of Maryland School of Dentistry, Baltimore,Maryland, [email protected]

Setareh Lavasani, DDS, MS, Diplomate, American Board of Oral and Maxillofacial Radiology, MABOMR, MADEA, MAAMC, MAAOMR,Assistant Professor, Department of Oral and Maxillofacial Radiology, Western University of Health Sciences, College of Dental Medicine, Pomona, California, [email protected][email protected]

Rima Abdallah, BDS, CAGS, D.Sc. (Oral Biol.),Diplomate, American Board of Periodontology,Assistant Professor, Department of Periodontology, Lebanese University, Faculty of Dental Medicine, Beirut,Adjunct Clinical Assistant Professor, Periodontology andImplantology Divisions, Oral Surgical Sciences Department,Beirut Arab University, Faculty of Dentistry, Beirut, Editor-in-Chief, International Journal of Oral and Dental Sciences,[email protected]

Carla Zogheib Moubarak, Dr. Chir. Dent., DES Endo.,MS Oral Biomat. Res., Dr. Univ.,Assistant Professor, Department of Endodontics,Saint-Joseph University, Faculty of Dental Medicine, Beirut, [email protected]@gmail.com

Chimène Chalala, BDS, DESS Orthod., ResidencyOrthod. AUB,Clinical Associate, Division of Orthodontics and DentofacialOrthopedics, American University of Beirut Medical Center,Associate Chief of Clinical Services, Department of Orthodontics,Lebanese University, Faculty of Dental Medicine, Beirut,[email protected]

Dimitar Filtchev, DDS, MS, Ph.D,Chief Assistant Professor, Department of Prosthetic Dentistry, Faculty of Dental Medicine, Medical University of Sofia, Sofia, Bulgaria [email protected]

Abbass El-Outa, BDS, DES Clin. Dent. ManagementDental Surgeon, Beirut, Lebanon [email protected]



54 Volume 52 - Nº 1 - January-June 2017

Dental Journalism: A Journey of a Lifetime.

"Without thought, there is little learning..... without reading, there is little to think about..... without discussion, it is difficult to distinguish between good and bad thinking ".

Robert Bruce Donoff, DMD, MD, Dean and Walter C. Guralnick Distinguished Professor of Oral and MaxilloFacial Surgery, Harvard School of Dental Medicine, Boston, USA

Since I was a young man, I always wanted to become a writer, a real writer, with the passion, dreams, and sleepless nights of a writer, knowing that I will never be an author by pure chance because this occupation takes a lot of knowledge,hard work, hustle, enterprising efforts, willful perseverance, and plenty of time slaving away at your computer. As an aspiring author, I spent most of my life thinking, reading as much as I can, worrying about getting published, and dreaming of becoming a recognized writer. Time passed, and after I graduated from dental school at Saint-Joseph University, Beirut, in 1981, I joined Paris University and affiliated hospitals in order to undertake my postgraduate course in oral surgery and oral pathology. Paris was the place where i discovered the real pleasure of creating search strings to specific subject areas in textbooks and journals; I also learnt there how to read, analyze, and address the content of a paper to my peers: I was so young facing this incomparable cognitive venture, and this pleasure turned, with time, to an insatiable hunger for knowledge. I read a raft of textbooks and papers, organized my home documents, attended workshops, conventions, and specialized seminars, exchanged challenging ideas with my seniors, and debated controversial topics with authors and scientists; this is how i spent most of my life occupying my mind and dragging myself into the "esthetics and deepness of knowledge". I was always suspended and torn between the nostalgia for ancient and new paradigms of modernity. I never knew -at that time- that i had to reshape my mind, discover the new world -with its objectivity and subjectivity-, and revisit science. Teeth and oral cavity were enough to help me discover the immensity of the universe and the unprecedented ingenuity of its designer; I didn't need to study and cover the whole human body to find my path, and since my first head and neck anatomy lesson with the late Professor Henri Badaro, back in 1976, at Saint-Joseph University Faculty of Dental Medicine, I was constantly in awe of the incomparable sophistication of the human skull and the perfection of structure in the whole human body. This unconditioned love for anatomy made me, later, a teacher of this stunning topic.

CURRICULUM VITAE

December 2012

ZIAD E. F. NOUJEIMOral Surgeon / Dental Educator

Oral Surgery, Oral Medicine,

Dental Implants, Facial Anti-Aging & Esthetic Medicine

Diplomate, European Board of Oral Surgery

Fellow, International College of Dentists

Fellow, American College of Oral and MaxillofacialSurgeons

Ziad E.F.NoujeimEditor-in-Chief, JLDA

EditorialDental Journalism: A Journey of a Lifetime. Ziad E.F. Noujeim

JLDA January-June 2017 issue dedicated to the Memory of Dean and Professor Elie Aramouni (1930 - 2016). Ziad E.F. Noujeim

Kathryn A. Kell - New FDI World Dental Federation President (2017-2019). Ziad E.F. Noujeim

Elie Ferneini - Editor-in-Chief of the American Journal of Cosmetic Surgery. Ziad E.F. Noujeim

Meet our third Editor-in-Subchief Josette Camilleri. Ziad E.F. Noujeim

Effect of different dental pulp capping materials using Er:YAG laser and conventional techniques on the secretion of IL-1ß and IL-6: An in vivo study. Cynthia Kassis Khoury, Pierre Khoury, Karim Corbani, Georges Hilal, Louis Hardan, Carole Chakar

Natural guided regeneration of periodontal and jaw defects by L-PRF: A “super” biomaterial for hard/soft tissue bio-engineering? Mira S. Haidar, Ziyad S. Haidar

The Cortical Lamina technique: A new option for alveolar ridge augmentation. Procedure, protocol, and case report.Roberto Rossi, Edoardo Foce, Salvatore Scolavino

Spatiotemporal coding in the brain: Promise of objective orofacial pain diagnosis. Carl Saab, Samah Abdul Baki

In vitro wear resistance of five composite restorative materials: A comparative research study. Ivan Chakalov, Pavlina Ivanova

Peri-implant bone radiolucencies: Reality or illusion? Sara Kassem Moussa, Saydé Sokhn, Ibrahim Nasseh

Occlusal outcome assessment of orthodontic treatments performed at an educational institute in Dubai. Fadi Iyad Elshafee, Shazia Naser-ud-Din, Amar Hassan Khamis, Athanasios E. Athanasiou

The “Neutral Zone” concept in removable complete denture fabrication: A salvation technique for severely resorbed mandibular ridges. Robert G. Mokbel, Tony Daher, Joseph J. Massad

Obturation of root canals with varying degrees of apical inflammatory root resorption in a mandibular second molar: A case report. Carla Jabre, Issam Khalil

Root canal treatment and hemisection of a decayed mandibular molar as a treatment option: A five-year follow-up case report. Marc García Font, Juan Gonzalo Olivieri, Francesc Abella, Jordi Ortega, Akram Hussein Ali, Miguel Roig Cayón, Fernando Durán-Sindreu

Deoxycholic acid injection for the reduction of submental fat in adults: An alternative to chin liposuction.Elie M. Ferneini, Mohammad Banki

Importance of dental photography in the practice of complex dentistry. Tony Daher

Supernumerary teeth: A clinical reminder. Marianne Saadé

JLDA Guide for Contributors and Authors

Volume 52 - N0 1 - January-June 2017

5

10

11

12

13

14

21

35

42

47

53

60

71

81

86

91

94

96

103


76 Volume 52 - Nº 1 - January-June 2017 Journal of the Lebanese Dental Association

taught me to look at myself in a fair-minded way. Before it, my thinking was left to itself; it was distorted, partial, often uninformed, biased, and sometimes prejudiced.

American author Mark Twain always repeated that "The secret of getting ahead is getting started". Therefore, and in order to prove my pen, I had to begin somewhere, sometime; for this reason, I started my editorial service in 2001-2002, as a reviewer for oral surgery, oral pathology, and anatomy, and as an editorial board member of the Lebanese University Dental Journal and the Journal of the Lebanese Dental Association -JLDA. At that time, I had to face four major challenges, as a junior, prospective dental editor and writer: growing and harvesting new ideas of interest to general dentists and specialists, managing time, looking for support from possible academic sponsors and associations,and mastering English language (which was not an easy task for a Lebanese, with Arab as native language). As a matter of fact, I became an editor by default, though I always wanted to be a writer. I started learning how to build clear and organized writing - which is the main foundation of an acceptable publication. I learnt how to design a layout that is capable of better conveying a new idea, and I became versed in making a page more inviting and attractive to our readers.

At my beginnings, I studiously read tens of manuscripts of all dental disciplines and specialties: from basic to clinical science, from restorative to prosthetic dentistry, from esthetic to surgical dentistry, from geriatric to pediatric dentistry, from oral medicine and pathology to periodontology, and from endodontics to implant dentistry. With time passing, I discovered that, while I was a destined editor, I was more capable and willing of showing zeal, always founding the opportunity to earn merit for my proper ascent. I thought I had the last word on all submitted manuscripts, but I was wrong! In truth, I marked almost all pages, rectified errors without mercy, repaired meanings, redressed aims and purposes that sounded unclear (to me !). At first glance, all this sounded easy and accessible: editing and proofreading marks, spelling elimination, grammar, and punctuation. But I discovered later that the task of a dental editor was far beyond these details: a dental reviewer and/or editor should help to make the scientific writing of a manuscript precise, clear, and rigorous. He/she revises the dental scientific semantics, and reduces inappropriate jargon, biased language, and awkward phrasing. He/she is also supposed to ensure that data and facts have been used consistently. Writing and editing techniques are not easy to learn and implement, but this comes with time, hard work, self-esteem and confidence building, dedication and maturity.

Unfortunately, dentistry and its different disciplines are sadly portrayed in popular culture with lot of humor and sarcasm, and one of the main responsibilities of a dental editor is to promote the dignity of the dental profession. In this regard, I made all possible efforts to abide by the Code of Dental Editors that was adopted by the Regents of the American College of Dentists -ACD- in March 2001, and by the American Association of Dental Editors -AADE- in October 2001; this remarkable and incomparable code determined the main responsibilities of dental editors, among them, making the publications as readable as possible by using a standardized style, taking active steps to ensure that manuscript's content is from reputable sources, reviewing submitted material in a fashion that is timely, confidential, constructive, ensuring consistency in the selection process, and remaining informed of emerging trends in the fields and subjects covered in the publication. You have to admire all these details in order to follow them. Editing is a way of life,it is not an easy task to express yourself via a written word, especially when you write an editorial, and finding a topic for an editorial is often burdensome and strenuous, for this task involves much effort, contemplation, and personal research.

Between 2001 and 2008, I concentrated my editorial work with the JLDA, as reviewer, editorial board member, and associate editor, and in 2008, I was asked by the Board of Directors and Council on Communications of the Lebanese Dental Association -LDA- to assume the role of Associate Editor-in-Chief, in order to assist my dear friend and colleague, and former JLDA Editor-in-Chief, Professor Philip E. Aramouni, in his task. Then, in 2009, I was promoted to the position of Editor-in-Chief of the JLDA, a further step in my accidental career in dental journalism.

My personal history with dental journalism begun in September 1981,with Professor Roger Diévart, at Paris 7 University Dental School, Department of Oral Surgery and Oral Medicine; immediately after I began my clinical training, Dr. Diévart assigned me the mission of addressing surgical dentistry clinical cases before heading to the operating theater; he also invited me to teach facial osteology tutorials for junior and senior years students. It was the first time I discover that Professor Badaro's quote was quite accurate: "Teach to Learn". Commercial Internet service providers were not available at that time. Indeed, and by 1994-1995, the Internet was fully commercialized in the USA. In order to gather information in France (at that time!), I had to do manual search of books' chapters, drawings, graphs, pictures, and full articles, and then gather them before photocopying. This time-consuming task is nowadays spared with modern computer networks, worldwide.

Teaching was my temporary escape from daily responsibilities that usually arise with a clinical career in a dental hospital. After I finished my 3-year postgraduate training in Paris, I began a part-time academic career in my home country, Lebanon, in 1985; working in academia was rewarding because it put me at the forefront of dental and oral science where I had to prepare formal and problem-based lectures on the last developments in oral surgery and pathology fields. I started addressing lectures and clinical teaching at Lebanese and Saint-Joseph Universities,in Beirut. I also endeavored lo lecture outside dental schools, in domestic conventions, and abroad.This hard piecework was prepared under the guidance of my late father, Fouad -who was a physician- and my first mentor and Dental Dean, the very famous Professor Elie Aramouni; they were both a source of inspiration for me and their commendable encouragements, help, and endless support, made most of my dreams come true, and I could not have realized what I always wanted without their blessed spirits that still dwell in me.

Teaching is the best lesson to reach humility because when we teach,we obviously discover how much we ignore. Teaching is the best way for building a critical spirit, which unequivocally leads us towards fairness, candor, straightforwardness, truthfulness, objectivity, impartiality, disinterestedness, neutrality, and intellectual honesty; the paucity of these attributes in human race makes authoring and editing a particularly difficult and delicate task. Thinking, reading, debating, analyzing, criticizing, taking notes, and designing abstracts are other traits of a good editor, and editing is certainly an excellent route to writing. Building writing and editing skills has to do with a personal discipline that is based on ethics, modesty, imagination, and, most importantly, knowledge.

In 1991, I was appointed Clinical Fellow at the Oral and Maxillofacial Surgery Department of the Massachusetts General Hospital -MGH-, in Boston, USA. MGH is the original and largest teaching hospital of Harvard Medical School and a biomedical research facility, it is still consistently ranked as one of the top 3 hospitals in the US. I worked there only for 3 months, watching, assisting on cases, and operating under local analgesia and general anesthesia. MGH, back in 1991, delivered a very high quality, comprehensive oral surgery patient care in a state-of-the-art out-patient and in-patient facilities. At that time, it was also a research powerhouse and one of the top recipients of research funding from the National Institutes of Health -NIH. In 3 months only, I had the honor to rub shoulders with the most gifted, skilled, and knowledgeable oral surgeons in the US, Dean and Professor Robert Bruce Donoff and his staff.

Again, I was confronting hard science and sharing a bewildering array of surgical opinions, and this helped me a lot to strive for excellence and precision. My diversified surgical rotation experience at Mass. General efficiently contributed to my development in the congnitive (knowledge), psychomotor (skills), and affective (behavior) domains. I had to complete many cases in the first scrub role before performing my personal cases. I learnt to measure my own performance and to critically build my "learning curve" in order to prepare for a stepwise ascent that will lead me, one day, to refine my surgical techniques and perform them competently and independently. And this was my main reward, considering that I never criticized myself after my dental graduation in 1981. Indeed, my MGH fellowship


Prior to 1840, dentistry had been indeed a "mechanical trade" in which charlatanism and secrecy obviously prevailed. In 2017, modern dental journalism is providing an excellent platform for scientific exchange in the fields of dental and craniofacial science. And with the multitude of dental journals,worldwide, the trend toward exclusiveness vanished, and the dental profession is evolving by sharing its knowledge with dental colleagues and the public. The first volume of the "Index to Dental Literature" included 65 journal titles, covering the years 1911 to 1915, and with the advent of a special Index, exclusively devoted to dental literature, Dentistry, as an independent profession, was separating from Medicine.

"A profession is weighed and judged by its educational standards,the importance of its accomplishments for the public welfare, and the quality of its literature" (BB Palmer, DDS, FACD, New York City, USA, 1931, in JADA).Introduced in 1950, the JLDA remains Lebanon's premier dental medium and one of the most reliable peer-reviewed sources on dentistry and its related specialties and disciplines in the Middle East, Near East, and Arab world. Through years and decades, the JLDA has changed and evolved, improving its appeal to its readers and incorporating contemporary cutting-edge topics, technologies, and clinical developments. The American Association of Dental Editors and Journalists -AADEJ- was chartered in 1931 and is composed of "dedicated people specifically interested in improving communication within the dental profession and in elevating the standards of dental journalism", and the JLDA abides by the aforementioned standards in recruiting reviewers and associate editors.

Dental journalism is, for me, much more than a scientific task, it is a true passion and a way of being. And because it is not only a temporary task or job, it turns into a lifetime journey! The journalist's role in health and biomedical sciences is highly ethical, as it was beautifully cited in the 1954 Declaration of Principles of Conduct of Journalists of the International Federation of Journalists: "Respect for truth and for the right of the public to truth is the first duty of Journalist.....". This job is a responsible one as well, just as Mark Twain marvelously illustrated, "Be careful about reading health books, you may die of a misprint !"

Ziad E.F. Noujeim, Dr. Chir. Dent., CES Oral Biol., CES Odont. Chir., Dipl. Oral Med., DU Cell Therapy, DIU Anti-Aging/Esthetic Medicine, DU Oral Dermatology, FICD, FACOMS, FIAOMS, Diplomate, European Board of Oral Surgery, Senior Lecturer and Postgraduate Tutor, Departments of Oral and Maxillofacial Surgery, Oral Medicine, and Basic Science,Former Director, Oral Surgery and Oral Pathology Postgraduate Programs, Lebanese University, Faculty of Dental Medicine, Beirut, Lebanon, Attending Oral Surgeon, Baabda University Hospital, Baabda, and Lebanese Army Central Hospital, Beirut,Scientific Chairperson, Lebanese Society of Oral Surgery,Former Scientific Chairperson, Lebanese Dental Association,Section Editor, Annals of Maxillofacial Surgery,Editor-in Chief, JLDAwww.drziadnoujeim.com

"What exactly does a dental editor do?" is a frequently asked question by our readers and Lebanese and Arab dentists. Journal editors are supposed to provide a critical function in scholarly communication, in addition to running the whole journal sections. This includes establishing of an efficient system for rapid peer-review, making reasonable and constructive editorial decisions, providing a very clear statement on journal's aim and policies on authorship criteria, treating all potential authors and co-authors with candor, respect, courtesy, honesty, transparency, fairness, and objectivity, and protecting the confidentiality of their submitted manuscripts, and, last but not least, cooperating with the publisher to ensure timely publication of accepted manuscripts. As a junior Editor-in-Chief, I always felt moments of personal irony when I compared my own role as the editor of the JLDA with that of the prestigious editors of international dental high impact factor journals, but, in life, we do what we are able and willing to do, not more. In truth, and with the invaluable help and assistance of our Editors-in-Subchief and Associate Editors, we established a philosophical direction for the JLDA, this direction dictating the screening policy of manuscripts submitted for publication. We decided to be open to clinical and review papers, as well as original research communications. We usually do not hesitate to reject a manuscript without further review because of redundancy or plagiarism. Other manuscripts are turned down if reviewers or associate editors deem that the manuscript's quality is not sufficient to merit further attention, but once a manuscript is considered for review, I usually read it and review it first before transferring it to, at least two of our specialized reviewers. And once the peer-review process has been completed by peer-reviewers and/or associate editors, I take my time to decide whether their decisions to reject, accept, or revise, are appropriate, and this is the hardest task because it happens that I disagree with one of them, and in that case, I communicate with the reviewers responsible for the specific manuscript and try to arrive with them at a final unified decision.

The multiple responsibilities of a Dental Journal Editor are not only scientific and ethical. This job requires a good lobbying that often results in encouraging prospective authors-especially young ones-to submit good material for possible publication.Also,we have to motivate our readers and all remaining dentists to read, discuss, debate, ponder, and implement -if possible- the information and clinical notes provided by JLDA papers.

JLDA's editors are anxious and eager to have their journal recognized for their efforts. Medical and Dental publishing became an extremely competitive enterprise, worldwide, and at several occasions, the Editors-in-Subchief, Associate Editors, and I communicate or meet to discuss past failures and successes and plan for future issues. Lately, we decided to become more popular by planning for a website and a Facebook account in order to ensure a Lebanese, Arab, and foreign ever-increasing readership. I also make certain that each JLDA issue includes an editorial -written by myself- or a guest editorial -written by an eminent personality.

Since I was a dental student, my teachers, tutors, and mentors at Saint-Joseph University repeated, at several occasions, that rise of Dentistry from a "mechanical trade" to a "profession" has been attributed to the triumvirate of journal literature,university education, and scientific organizations. According to Sara Anne Hook (1985), the former public services librarian at Indiana University School of Dentistry,in Indianapolis, USA, "the evolution of dental journals from trade house publications to independent scientific literature mirrored the movement toward professional status in dentistry during the late 19th and early 20th centuries".

The year 1839 witnessed the appearance of the first dental journal,the "American Journal of Dental Science", and the first Dental School, the "Baltimore College of Dental Surgery", was established and launched in 1840.Since these important dates, Dental Journalism made its advent in the US,for nowhere else in the entire world were conditions so favorable (WH Trueman, 1920, in Dental Cosmos). And 178 years after the appearance of the first dental medium, independent dental journalism is nowadays a true base for the science-based evolution of our profession, and if many of us feel that some dental manufacturers are responsible for the poor literature quality of some dental journals, it is not the fault of these manufacturers, but of the editors in charge of these biased publications.


1110

Kathryn KellNew FDI World Dental Federation President

(2017-2019)

On September 24th, 2015, in Bangkok, Thailand,and during the Annual World Congress, Dr. Kathryn A. Kell, an American Dental Association -ADA- active member, won the chief election at the FDI. The FDI World Dental Federation is composed of approximately 200 national dental associations, from more than 130 countries. It represents over one million dentists worldwide.

As President-Elect of FDI, Dr. Kell intensively focused on oral health promotion, public health and preventive dentistry, dental advocacy, strategic planning, and financial management.

Dr. Kell is the President and owner of Kathryn A. Kell DDS PC (since April 1979), a dental general family practice located in Davenport, Iowa, USA. She worked as a general dentist for more than 40 years and served as Dental Leader with the FDI for almost 2 decades,and,more recently, as Treasurer. She is the Past President of the Iowa Dental Association and a past ADA Trustee (2004 to 2008). Dr. Kell is known to be committed to leadership and to the dental community, she is a dedicated powerful voice for dentistry and the dental profession.

By embracing habits, cultures, and ideas of all FDI members, Dr. Kell succeeded in building strong bridges between dental communities and professional associations and directly helped to further the practice of Dentistry, making the patient's experience constructive and more positive.

Dr. Kell holds the DDS degree and a Masters in Health Care Administration (MHCA). During her life-long professional life, she held many key positions and responsibilities, among them Past President of American Association of Women Dentists (1983 to 1989), Past Chair of the Council on ADA Sessions and International Programs (1996 to 1999), Past Chair of the FDI Education Committee (1998 to 2007), Past Member of the ADA Board of Trustees (2004 to 2008), Past Chair of the ADA Committee on International Programs and Development (2008 to 2012), Past Council Member of the FDI (2008 to 2011), Past Treasurer of the FDI and Executive Committee Member (2011 to 2015), and President-Elect of the FDI (2015 to 2017).

The great reputation Dr. Kell built over time made her a perfect Dental Activist and a World's Advocate for Dental and Oral Health.

Our heartfelt congratulations and best wishes for Dr. Kell and her family !

Ziad NoujeimJLDA Editor-in-Chief

The JLDA JANUARY -JUNE 2017 ISSUE

is

DEDICATED

to the MEMORY

of

ELIE ARAMOUNI(1930-2016)

Pioneer in Dentistry and Dental Education

- Founding and First Dean of the Saint-Joseph University Faculty of Dental Medicine, Beirut, Lebanon (1975-1991)

- Professor of Operative Dentistry and Endodontics, Saint-Joseph University Faculty of Dental Medicine (1963-1995)

- Directeur de l'Ecole Dentaire de la Faculté Française de Médecine et de Pharmacie of Saint-Joseph University (1969-1975)

- President of the Lebanese Dental Association - LDA (1967-1970)



1312

Meet our third Editor-in-SubchiefJosette Camilleri, B.Ch.D., M.Phil., Ph.D., FADM, FIMMM, FHEA

In January 2017, Dr. Josette Camilleri was appointed Editor-in-Subchief of the Journal of the Lebanese Dental Association-JLDA. Dr. Camilleri is presently Professor of Restorative Dentistry and Endodontics, School of Dentistry, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, England, UK. She also served as Associate Professor and Research Scientist in the Department of Restorative Dentistry at the University of Malta Faculty of Dental Surgery, in Msida, Malta.

Dr. Camilleri earned her Bachelor, Masters, and Doctoral degrees (BChD., MPhil., PhD) at the University of Malta. She begun her teaching career in 1994 as part-time visiting Lecturer and Clinical Demonstrator at the same University. In 2004, she begun her research career as Research Assistant to the late Professor Tom Pitt Ford,at the Department of Endodontics at King's College London -KCL- Guy's Dental Institute, in England, UK, and between 2006 and 2008, she was Deputy Director of Civil Engineering Laboratories at the Faculty for the Built Environment, at the University of Malta. Between 2009 and 2017, she worked as Associate Professor and Researcher in the Department of Restorative Dentistry at the University of Malta, a Department that she chaired during the year 2014.

Professor Camilleri is a distinguished and influential dental professional, and a world- renowned scientist and dental clinician, having extensively lectured in Lebanon, Italy, UK, Brazil, South Africa, India, Egypt, Libya, UAE, France, Spain, Belgium, and The Netherlands. She is the author of 8 book chapters and more than 100 scientific papers indexed in PubMed. She is an international expert in restorative dentistry and dental restorative materials and has published on several "restorative" topics,among them,biocompatibility of dental materials,bonding over dentin replacement materials, pulp capping materials, cement-dentin interface, XPS and XRD analysis of the effect of polishing instruments and polishing regimens on surface topography and phase transformation of monolithic zirconia, SEM evaluation of the material interface of adjacent layers of dental materials, antimicrobial properties of restorative filling materials, physicochemical properties of endodontic sealers and dental restorative materials, dental endosseous implants coating materials, dentin bond strength, root canal irrigation, Portland cement hydration, silicate cements and resins, MTA, MTA Plus, and Biodentine, and many other research and clinical topics related to endodontology and restorative dentistry.

Professor Camilleri is the author and co-author of 100 peer-reviewed publications in international journals and 8 books and book chapters. She is Associate Editor of the Journal of Applied Science and reviewer for many scholarly publications in the areas of dentistry and biomedical sciences, among them the Journal of Dental Research, the Journal of Endodontics, the International Endodontic Journal, Clinical Oral Investigations, Acta Odontologica Scandinavica, Acta Biomateriala, Dental Materials, the Journal of Dentistry, the Journal of Adhesive Dentistry, Cement and Concrete Composites, the Journal of Biomedical Materials Research, and the Arabian Journal for Science and Engineering.

Our heartfelt congratulations and best wishes to Professor Camilleri and her family.Ziad Noujeim

JLDA Editor-in-Chief

Elie Ferneini Editor-in-Chief of the American Journal of Cosmetic Surgery

In January 2017, Dr. Elie M. Ferneini, one of the JLDA Editors-in-Subchief, was officially appointed the new Editor-in-Chief of the American Journal of Cosmetic Surgery-AJCS, the scientific publication of the American Academy of Cosmetic Surgery-AACS. Dr. Ferneini succeeded Dr. Jane M. Ptero, MD, who served the AJCS for almost ten years.

Dr. Ferneini is a graduate of Southern Connecticut State University (BS/Magna Cum Laude),Quinnipiac University (MBA, MHS) and the University of Connecticut Dental and Medical Schools (DMD, MD). He is Assistant Clinical Professor at the University of Connecticut Division of Oral and Maxillofacial Surgery,Connecticut, USA, Diplomate of the American Board of Oral and Maxillofacial Surgery-DABOMS, and Fellow of the American College of Surgeons-FACS.

Professor Ferneini's clinical expertise is focused on both office-based and hospital oral and maxillofacial surgical procedures, with an emphasis on cervico-facial esthetic and anti-aging medicine.

As Lebanese American health professional and public figure, Professor Ferneini has expanded awareness of the JLDA to a wider audience of Lebanese and American dental students and dentists, in the USA and Arab countries, helping the JLDA to reach a higher level of international recognition , esteem and respect.

The JLDA and the Lebanese Dental Community are proud to share in Professor Ferneini many notable accomplishments and achievements-clinical skillfulness and competence, academic excellence and merit, and well-deserved peer recognition. This appointement is an additional indication of his profound impact on dentistry,oral and maxillofacial surgery, esthetic and anti-aging medicine, and cosmetic surgery. We are fully confident that he will bring to the AJCS further success and excellence, and a remarkable level of brilliance, distinction, zeal and enthusiasm .

Our heartfelt congratulations and best wishes to Professor Ferneini and his family.

Ziad NoujeimJLDA Editor-in-Chief



1514 Journal of the Lebanese Dental Association

dentinal reparative bridge.2

Inflammatory process may lead to either dental pulp repair, with or without dentin bridge formation, fibrosis or necrosis3. Inflammatory chemokines direct the traffic of immune cells and cytokines induced during T-cell activation to regulate immune and inflammatory responses. Many cytokines produced by innate immune cells are produced by activated T cells in adaptive immunity. Activated macrophages produce Tumor Necrosis Factor-alpha (TNF-ɑ), IL-1, IL-6, IL-12, IL-10, chemokines, and short-lived lipid mediators such as platelet activating factor (PAF), prostaglandins, and leukotrienes in order to orchestrate a local inflammation.4

Production of cytokines can be used to analyze inflammatory potential of different materials. There are now evidences that inflammation is a prerequisite for pulp healing, with series of events ahead of regeneration. Immunocompetent cells are recruited in the apical part of dental root. Due to the high alkalinity of capping agent, pulp cells display mild inflammation, proliferate, increase in number and size, and initiate mineralization.5

IL-1β is an inflammatory molecule of the dental pulp. IL-1β stimulates cyclooxygenase-2 (COX-2) and prostaglandins production of pulp cells and affects pulpal inflammation and repair.6

IL-6 is a proinflammatory cytokine secreted by T cells, monocytes, fibroblasts, epithelial cells, and macrophages, in response to antigen and other cytokines such as IL-1 and TNF-ɑ7.

Several techniques and biomaterials for dental pulp capping are used: Calcium-hydroxide-based cement was patented in 1962, and the first clinical study on Dycal® (Dentsply Caulk, Milford, DE, USA) was reported in 1963, with a success rate of 85%.8

Calcium hydroxide materials are the most commonly used dental pulp capping agents because of their ability to encourage tissue repair by promoting tertiary dentin secretion and providing antibacterial activity via their high alkaline pH.9

Biodentine™ with active biosilicate technology, announced by dental material manufacturer Septodont in September 2010, can be used not only as an endodontic repair material but also as a coronal restorative material for dentin replacement10.

With the fast improvement in technology, contemporary lasers have different types of applications in dentistry, depending on their type, power, energy, and effects on oral and dental tissues.11

Laser technology proved to be effective in improving the prognosis of pulp capping procedures.12 The use of a laser for direct pulp capping has been suggested because of its considerable advantages, including decontamination, biostimulation, hemostatic, and coagulant effects.13

The aim of the present study was to evaluate the effect of different dental pulp capping biomaterials using the conventional technique or Er:YAG laser on the secretion of IL-1β and IL-6, one month after pulp effraction.

MATERIALS AND METHODSThis study was conducted at the laboratories of

Saint-Joseph University, Beirut, Lebanon.A total of 42 healthy, mature, permanent maxillary

and mandibular incisor teeth (Fig. 1) of 7 rabbits (3.5-4 kg weight) were included in the study. Animals were anesthetized by intraperitoneal injection of a combination of ketamine (Imalgene 500, Merial, France) (50mg/ml) and xylazine (Rompun, Bayer, France) (25mg/ml).

Fig. 1. Preoperative specimens. Fig. 2. Pulp exposure with a high-speed round bur.

Fig. 3. Pulp exposure with Er:YAG laser.

INTRODUCTIONDirect dental pulp capping is a procedure used to

cover an exposed pulp by a biocompatible material to promote dentinal bridge’s formation.Biocompatibility or inflammatory effects of pulp capping materials are important to avoid pulp tissue irritation or degeneration.1 Capping procedure leads to a local inflammatory process, leading to pulp cells recruiting: these cells proliferate and differentiate into odontoblast/osteoblast-like cells that produce an extracellular matrix which turns out to be a scaffold for amineralized

Effect of different dental pulp capping materials using Er:YAG laser and conventional techniques on the secretion of IL-1ß and IL-6: An in vivo study.Cynthia Kassis Khoury1, Dr. Chir. Dent., MS (Oral Surg.), DU Oral Pathol., DU Restor. Dent., Pierre Khoury2, BDS, DESS Prostho., Karim Corbani3, Dr. Chir. Dent., DES Endo., MAACD, MASDA,Georges Hilal4, Ph.D., DEPD,CSPQ,Louis Hardan5, Dr. Chir. Dent., DEA (Biol.), Dr. Univ., Carole Chakar6, Dr. Chir. Dent., CES Oral Biol., CES Perio., DU Perio., MS (Biol. Sc.), Dr. Univ.

AbstractIntroduction: Direct dental pulp capping induces a local inflammatory process. Several biomaterials have been

used for this procedure. The aim of this study was to evaluate the effect of different pulp capping biomaterials using the conventional technique or Erbium:YAG (Er:YAG) laser on the secretion of interleukin-1 beta (IL-1β) and interleukin 6 (IL-6), one month after pulp effraction.

Materials and Methods: 42 Class V cavities were prepared on buccal surface of 4 maxillary incisors and 2 mandibular incisors. Specimens were devided into 6 treatment groups: Group 1: teeth were treated with Erbium:YAG laser and Biodentine® Septodont. Group 2: teeth were treated with Erbium:YAG laser and self-hardening calcium hydroxide (Dycal® Dentsply). Group 3: teeth were treated with traditional rotating instruments and self-adhesive resin (Prime & Bond® NT™ Dentsply). Group 4: teeth were treated with traditional rotating instruments and Biodentine®. Group 5: teeth were treated with Erbium:YAG laser and self-adhesive resin. Group 6: teeth were treated with traditional rotating instruments and self-adhesive resin (Prime & Bond® NT™ Dentsply). Animals were sacrificed at day 30 and teeth were isolated and prepared for examination and evaluation using ELISA kits for detecting and quantifying IL-1ß and IL-6.

Results: The mean proportion of IL-1β was not significantly different between turbine and laser with Biodentine® (-p-value=0.453), Dycal® (-p-value=0.143) and self-adhesive resin (-p-value=0.899). Mean proportion of IL-6 was not significantly different between turbine and laser with Biodentine® (p=0.076), Dycal® (p=0.164) and self-adhesive resin (p=0.459).

Conclusion: These techniques and biomaterials proved to be useful for direct pulp capping. Biodentine®, Dycal®, and self-adhesive resin were used for 4 weeks in order to evaluate their effect on IL-1ß and IL-6 secretion; concentrations of IL-1ß and IL-6 were reduced in capped teeth but no differences were observed between these three biomaterials.

1. Senior Lecturer and Clinical Tutor, 2. Clinical Instructor, Department of Prosthodontics, Lebanese

University, Faculty of Dental Medicine, Beirut, Lebanon3. Senior Lecturer and Clinical Tutor4. Biochemist and Research Scientist, Cancer and Metabolism

Laboratory, Saint-Joseph University, Faculty of Medicine, Beirut, Lebanon

5. Associate Professor and Chairperson, 6. Assistant Professor, Department of Periodontology, Saint-

Joseph University, Faculty of Dental Medicine, Beirut, Lebanon

1,3,5. Department of Restorative and Esthetic Dentistry, Saint-Joseph University, Faculty of Dental Medicine, Beirut, Lebanon

Dental Research



IL-1 beta levels in serum, plasma, and culture media. It contains Escherichia coli-expressed recombinant Rabbit IL-1ß and antibodies raised against recombinant factor and has been shown to accurately quantitate recombinant Rabbit IL-1ß. This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for IL-1 has been pre-coated onto a microplate. Standards and samples were pipetted into the wells and any IL-1 present is bound by the immobilized antibody. After washing away any unbound substances, an enzyme-linked polyclonal antibody specific for IL-1ß was added to the wells. Following a wash to remove any unbound antibody-enzyme reagent, a substrate solution was added to the wells. After an incubation period, an amplifier solution was added to the wells and color developed in proportion to the amount of IL-1 bound during the initial step. Color development was stopped and the intensity of color measured at 450 nm and the concentrations of unknown samples were assessed using the standard curve (Fig. 4).

The Quantikine HS Rabbit IL-6 Immunoassay is a solid-phase ELISA designed to measure Rabbit IL-6 in serum, plasma, and urine. It contains E. coli-expressed recombinant rabbit IL-6 and it has been shown to accurately quantitate the recombinant factor. This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for IL-6 has been pre-coated onto a microplate. Standards and samples were pipetted into the wells and any IL-6 present was bound by the immobilized antibody. After washing away any unbound substances, an enzyme-linked polyclonal antibody specific for IL-6 was added to the wells. Following a wash to remove any unbound antibody-enzyme reagent, a substrate

solution was added to the wells. After an incubation period, an amplifier solution was added to the wells and color developed in proportion to the amount of IL-6 bound during the initial step. Color development was stopped and intensity of color was measured at 450 nm and the concentrations of unknown samples were assessed using the standard curve (Figs. 5, 6).

RESULTS Statistical Analysis

Statistical analyses were performed using SPSS** for Windows version 18.0. The alpha error was set at 0.05. The outcome variables of the study were the proportion of IL-1ß and IL-6.

The Kolmogorov-Smirnov (K-S) test was used to assess the normality of the distribution of variable.

Repeated measure analysis of variance was used to compare the mean proportion of IL-1ß and IL-6 according to material (Biodentine®, Dycal®, and adhesive resin) and technique (Er:YAG laser and conventional technique). It was followed by univariate analysis and Tukey's multiple comparison test (Table 1).

The mean proportion of IL-1ß was not significantly different between Biodentine®, Dycal®, and self-adhesive resin when associated with conventional technique (p=0.206) or laser (p=0.708).

The mean proportion of IL-1ß was not significantly different between turbine and laser with Biodentine® (-p-value=0.453), Dycal® (-p-value=0.143) and self-adhesive resin (-p-value=0.899) (Table 2).

In the group performed with rotating instrument, the mean proportion of IL-6 was not significantly different between Biodentine®, Dycal®, and self-adhesive resin (p=0.528).

In the group performed with Er:YAG laser, the

Fig. 5. Reagent preparation for IL-6.

** SPSS = Statistical Package for the Social Sciences (SPSS is a predictive analytics software used to perform data entry and analysis and to create tables and graphs).

Fig. 6. ELISA kit.

42 Class V cavities were prepared on buccal surface of 4 maxillary and 2 mandibular incisors. They were divided into 2 groups:

- 21 class V cavities were prepared and in the center of the cavity, pulp exposure was created using a high-speed round diamond bur (0.2mm) without excessive pressure and under abundant air/water spray coolant (Fig. 2).

- 21 cavities were prepared and pulps were exposed by a 0.2 tip of Er:YAG laser irradiation at an energy level of 200mJ, frequence 15 Hz, with water 4 % and with 6% air (Fig. 3).

All dental pulps were capped with different materials.

- Biodentine® (Septodont), mixed according to the manufacturer’s instructions,

- Calcium hydroxide, CH paste (Dycal®). - Self-adhesive resin ( Prime & Bond® NT™ Dentsply).All cavities were subsequently filled with a bulk- fill

flowable composite SDR (DENTSPLY) and covered by Esthet-X composite (DENTSPLY).

2 rabbits were lost, 2 weeks after the launching of the treatment. Animals were sacrificed at day 30 and teeth were isolated and prepared for examination and evaluation. Specimens were placed in Dulbecco’s Modified Eagle’s Medium (DMEM) with penicilline and streptomycine. DMEM is a modification of Basal Medium Eagle (BME) that contains a four-fold higher concentration of amino acids and vitamins, as well as additional supplementary components. Specimens were incubated for 5 days, then each 1 ml of the solution was transferred to a tube and frozen at -80ºC.

This study involved two treatment steps: first

step involved preparation of exposed pulp tissue and surrounding dentin, whereas second step consisted of sealing the exposed pulp with one of the aforementioned dental materials.

Specimens were divided into 6 treatment groups:Group 1: teeth were treated with Er:YAG laser and

Biodentine® (Septodont).Group 2: teeth were treated with Er:YAG laser and

self-hardening calcium hydroxide (Dycal® Dentsply).Group 3: teeth were treated with traditional rotating

instruments and self-adhesive resin (Prime & Bond® NT™ Dentsply).

Group 4: teeth were treated with traditional rotating instruments and pulp capping Biodentine®.

Group 5: teeth were treated with Er:YAG laser and self-adhesive resin.

Group 6: teeth were treated with traditional rotating instruments and self-adhesive resin (Prime & Bond® NT™ Dentsply).

ELISA*Protein quantification was carried out with ELISA

kits for IL-1ß (RPN-5971, Biotrak™, Amersham Pharmacia Biotech, Buckinghamshire, UK) and IL-6 (RPN-5969, Biotrak™ Easy ELISA) following the manufacturers’ instructions. Data obtained from each well (three independent wells for each sample) were submitted to Levene’s statistical test, which confirmed their normal distribution. Data were statistically analyzed by analysis of variance (ANOVA; P<0.05) and complemented by Tukey’s posthoc test (P<0.05).

The Quantikine HS Rabbit IL-1 beta Immunoassay is a solid phase ELISA designed to measure rabbit

Fig. 4. Reagent preparation for IL-1ß

*ELISA = Enzyme-Linked Immunosorbent Assay: a technique used for detecting and quantifying substances such as antibodies, proteins, peptides, and hormones.


According to Jayawardena and co-workers21, Er:YAG laser–exposed pulp tissue demonstrated good healing capacity with the formation of a dentin bridge and reparative dentin. Furthermore, Er:YAG laser removed dentin chips at the exposure site,leading to the formation of homogeneous dentin bridge, formed at a faster rate by odontoblasts, which were differentiated from pulp cells.21

The use of lasers for direct pulp capping showed great promise with respect to clinical and basic sciences because of their versatility and wide applicability.22

Antimicrobial activity of different pulp-capping materials has shown a direct influence on the healing process. Poggio and associates23 tested the effect of Dycal® (Dentsply Tulsa Dental), Calcicur® (Voco GmbH), Calcimol LC® (Voco GmbH), TheraCal LC® (Bisco Inc), MTA-Angelus® (Angelus), and Biodentine® (Septodont): authors confirmed the antibacterial activity of calcium hydroxide, as reported in previous studies (Mohammadi et al., 2012 - Siqueira JF Jr and Lopes, 1999 - Estrela et al., 1999 - Bystrom et al., 1985 - Stevens and Grossman, 1983 - DiFiore et al., 1983).The antibacterial activity of Ca(OH)2 is based on the release of hydroxyl ions in solution which are highly oxidant free radicals that show extreme reactivity with several biomolecules.23

Anti-inflammatory effects of low-power laser irradiation have previously been reported. The mechanism by which laser irradiation regulates expression of inflammatory cytokines remains unknown, even though low-power laser irradiation regulates intracellular signaling molecule activities to exert its anti-inflammatory effect.24

In the present study, a period of 4 weeks was chosen to evaluate the effect of different capping materials and techniques on the secretion of interleukines 1ß and 6. Concentrations of IL-1ß and IL-6 were reduced in capped teeth but no differences were observed between the 3 biomaterials. Kramer and co-workers17 found similar results at 30 days after capping.

Adhesive systems have expanded the range of possibilities of teeth restoration. However, when they are placed in contact with dental pulp, they may trigger an inflammatory process of variable intensities.3

IL-1ß is produced in response to inflammatory agents, infections, or microbial endotoxins. It plays a central role in immune and inflammatory responses,

bone remodeling, fever, and carbohydrate metabolism.This cytokine production after calcium hydroxide

stimulation can be related to the fact that the IL-1ß has different functions according to its dose and time of action, during different phases of inflammation, including inflammation control.25

It was observed that after 24 hours, calcium hydroxide has stimulated the production of IL-1ß, without stimulating IL-8. Conversely, the adhesive resin and formocresol stimulated the production of IL-8, and did not stimulate IL-1ß.15

Mean proportion of IL-6 was not significantly different between turbine and laser with Biodentine® (p=0.076), Dycal® (p=0.164), and self-adhesive resin (p=0.459).

IL-6 is a pleiotropic cytokine that acts during the acute phase reaction, inflammation, hematopoiesis, bone metabolism, and cancer progression. It contributes to chronic inflammation .

CONCLUSIONFor many years, the importance of inflammation

in pulp healing has been underestimated, considered only to be an undesirable effect, leading in most cases to pulp necrosis. Recent results from different studies showed that the inflammatory process should be re-examined to understand the potentially beneficial effect of this process.2

In the present study, we evaluated the effect of Biodentine®, Dycal®, and self-adhesive resin in-vivo, on pulp tissue cytokine response to pulp injury: our results showed that the three aforementioned biomaterials have an anti-inflammatory effect which may influence dentinal bridge formation that favors pulp healing.

These biomaterials, pulp capping conventional techniques, and Er:YAG laser technique proved to be useful and efficient for pulp capping. IL-1β and IL-6 secretions and concentrations were reduced in capped teeth, 4 weeks after application of Biodentine®, Dycal®, and self-adhesive resin, but no differences were observed between these three biomaterials.

Further studies on histological aspect of dental pulp response to such biomaterials are warranted in order to compare dentinal bridge thickness using different pulp capping biomaterials or conventional techniques or laser-assisted techniques.

mean proportion of IL-6 was higher with self-adhesive resin (p=0.016); No significant difference was found between Dycal® and Biodentine® (p=0.893).

The mean proportion of IL-6 was not significantly different between turbine and laser with Biodentine® (p=0.076), Dycal® (p=0.164), and self-adhesive resin (p=0.459).

DISCUSSIONPulp capping is a technique that aims to preserve

vitality of dental pulp, and to use a material that leads pulp cells to stimulate deposition of a hard tissue bridge.14

After exposing pulp tissue, cytokines are produced in order to promote pulp inflammatory response.15 If pulp is exposed, stem cells or progenitors located within the pulp are recruited: they proliferate and differentiate and start to produce an extracellular matrix that will ultimately undergo mineralization. This cascade of events leads to the elaboration of a reparative dentin in the form of a thin dentinal bridge occluding exposure site.16

A very relevant danger for dental pulp tissue after direct pulp capping is a bacterial infection that can

cause inflammation and pulp necrosis.17

Many researchers have used several materials and techniques to compare pulpal response and cytokines secretions: Asgary and co-workers18 demonstrated that because of its low-grade irritation potential of traumatized pulp tissue, calcium hydroxide [Ca(OH)2] is the material of choice for pulp capping, despite three known disadvantages for this biomaterial such as gradual degradation, tunnel defects in dentinal bridge, and poor sealing properties.18

Mechanical properties of pulp capping materials may affect their resistance to fracture during placement of a final restorative material or while supporting an overlying restoration over time. Nielsen and associates19 demonstrated that Biodentine® had greater stiffness after 3 hours, to potentially provide better support of an overlying restoration under function over time.19

Adaptation of pulp capping materials to prepared tooth surface may be the key to the success of biological tooth treatment. Stefanova and co-workers20 proved that dentin surface prepared with Er:YAG laser demonstrates a very good adaptation of the three tested pulp capping biomaterials.20

Table 2. Mean proportion of IL-6 among groups.

Table 1. Mean percentage of IL-1ß among groups.

IL-1ß Biodentine Dycal self adhesive resin Sig.

Turbine Mean ±SD 0.332 ± 0.388 0.062 ± 0.072 0.251 ± 0.186 0.206

Laser Mean ±SD 0.133 ± 0.187 0.202 ± 0.197 0.271 ± 0.252 0.708

Sig. 0.453 0.143 0.899

IL6 Biodentine Dycal self adhesive resin Sig

Turbine Mean ±SD 0.014±0.007

N=5

0.0165±0.008

N=5

0.0213±0.0125

N=5

0.527

Laser Mean ±SD 0.009 ±0.009

N=5

0.008 ±0.009

N=5

0.022±0.0109

N=5

0.016

Sig 0.076 0.164 0.459

Comparison of IL-1ß

Comparison of IL-6

2120

INTRODUCTIONDespite recent significant improvements in

reconstruction techniques and materials biotechnology, regeneration of defects remains a challenge1. Indeed, current clinical approaches used to reconstruct and heal complex defects, including different bone grafting methods, such as autologous bone grafts, allografts, bone-graft substitutes, distraction osteogenesis, and/or guided bone regeneration, are deemed restricted. This is often multi-factorial, whether due to limited self-

renewal capacity of the defect and/or the limited donor supply, increased morbidity, and risk of antigenicity and foreign body reactions associated with the grafts used. Operative-associated time and cost contribute as well. Hence, the art and science of oro-maxillo-facial reconstruction is of great interest for contemporary oral and maxillofacial surgeons in search for better bioengineering strategies and biomaterials: a core driver for biodental research, today2.

Platelet concentrates are autologous blood extracts obtained through centrifugation of whole blood samples. Preparation procedure allows the gathering and concentration of platelets and other therapeutic blood constituents (fibrinogen/fibrin, growth factors, leukocytes and circulating cells) in clinically-usable preparations (surgical adjuvants), which may enhance, accelerate and promote wound healing and regeneration of hard and soft tissues 3. Despite promising clinical observations, their overall effectiveness remains

Natural guided regeneration of periodontal and jaw defects by L-PRF: A “super” biomaterial for hard/soft tissue bio-engineering?Mira S. Haidar1,2, Dr. Chir. Dent., M.Sc., Private Practice, Santiago de ChileZiyad S. Haidar1,3-5, DDS, Cert. Implant., M.Sc.(OMFS), FRCS(C), MBA, Ph.D., Profesor Investigador y Director BioMAT'X, Director Cientifico del Facultad de Odontologia, Universidad de los Andes, Santiago, Chile

AbstractLeukocyte and Platelet-Rich Fibrin (L-PRF) is a 3-D autogenous biomaterial obtained via simple and rapid

centrifugation of patient's whole blood patient samples, in absence of anti-coagulants, bovine thrombin, additives or any gelifying agents. A relatively new “revolutionary” step in second generation platelet concentrate-based therapeutics, clinical effectiveness of L-PRF remains highly debatable, whether due to preparation protocol variability, limited evidence-based clinical literature and/or inadequate understanding of its bio-components. This critical review provides an update on the application of L-PRF during oral surgery procedures, in human randomized and controlled clinical trials only (up to February 2016). Accordingly, autologous L-PRF is often associated with early bone formation and maturation; accelerated soft-tissue healing; and reduced post-surgical pain and discomfort. L-PRF is a simple, malleable, and safe biomaterial suitable for use in oral surgery. Being innovative tool in regenerative dentistry, L-PRF is a strong alternative and possibly cost-effective biomaterial for oral-tissue regeneration. Preparation protocols require revision and standardization. Furthermore, a good analysis of its rheological properties, bio-components and their bioactive function would enhance the validity, comprehension and therapeutic potential of reported findings or observations; a step closer towards a new era of “super” dental biomaterials and bioscaffolds.

1.BioMAT’X, Facultad de Odontología, Universidad de Los Andes, Santiago de Chile.2. Formerly Programa de Diplomado en Endodoncia, Facultad de Odontología, Universidad de Los Andes, Santiago de Chile.3. Plan de Mejoramiento Institucional (PMI) en Innovación I+D+i, Universidad de Los Andes, Santiago de Chile.4. Programa de Doctorado en BioMedicina, Facultad de Medicina, Universidad de Los Andes, Santiago de Chile.5. Centro de Investigación Biomédica, Facultad de Medicina, Universidad de Los Andes, Santiago de Chile.

Regenerative Dentistry

Conflict of Interest Disclosure StatementThe authors affirm that they have no financial

affiliation (employment, honoraria, direct payment, stock ownership, consultantships, patent licensing arrangements) or involvement with any commercial organization or corporation, with any direct financial or economic interest in the subject or materials discussed in this manuscript. Any other potential conflict of interest is disclosed.

REFERENCES1. Chang S, Bae W,Yi J, Lee S, Lee D, Kum K, Kim E.Odontoblastic Differentiation, Inflammatory Response, and Angiogenic Potential of 4 Calcium Silicate–based Cements: Micromega MTA, ProRoot MTA, RetroMTA, and Experimental Calcium Silicate Cement.J Endod 2015;41:1524–1529.2. Goldberg M, Farges JC, Lacerda-Pinheiro S. et al. Inflammatory and immunological aspects of dental pulp repair. Pharmacol Res 2008 Aug;58(2):137–147.3. Cavalcanti BN, Rode Sde M, França CM, Marques MM. Pulp capping materials exert an effect on the secretion of IL-1β and IL-8 by migrating human neutrophils. Braz Oral Res. 2011 Jan-Feb;25(1):13-8.4. Hahn C, Liewehr F. Update on the Adaptive Immune Responses of the Dental Pulp. J Endod 2007;33:773–781.5. Goldberg M, Njeh A, Uzunoglu E. Is Pulp Inflammation a Prerequisite for Pulp Healing and Regeneration? Mediators Inflamm 2015;2015:347649. 6. Chang MC1, Tsai YL2, Chang HH3, Lee SY4, Lee MS2, Chang CW4, Chan CP5, Yeh CY2, Cheng RH4, Jeng JH6. IL-1β-induced MCP-1 expression and secretion of human dental pulp cells is related to TAK1, MEK/ERK, and PI3K/Akt signaling pathways. Arch Oral Biol 2016 Jan;61:16-22. 7. Silva M, Vieira L ,Sobrinho A , Horizonte B The effects of mineral trioxide aggregates on cytokine production by mouse pulp tissue.Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;105:e70-e768. Komabayashi T, Zhu Q, Eberhart R and Imai Y. Current status of direct pulp-capping materials for permanent teeth. Dent Mat J 2016;35(1):1-129. Cengiz E, Yilmaz H. Efficacy of Erbium, Chromium-doped:Yttrium, Scandium, Gallium, and Garnet Laser Irradiation Combined with Resin-based Tricalcium Silicate and Calcium Hydroxide on Direct Pulp Capping: A Randomized Clinical Trial. J Endod 2016;42(3):351-35510. Kenchappa M1, Gupta S, Gupta P, Sharma P J Dentine in a capsule: clinical case reports. Indian Soc Pedod Prev Dent. 2015 Jul-Sep;33(3):250-254. 11. Seyed Mohsen Hasheminia & Ghader Feizi & Seyed Mohammad Razavi & Mahboobe Feizianfard & Norbert Gutknecht & Maziar Mir .A comparative study of three treatment methods of direct pulp capping in canine teeth of cats: a histologic evaluation.Lasers Med Sci 2010;25:9-15.12. Olivi G1, Genovese MD, Maturo P, Docimo R Pulp capping:

advantages of using laser technology. Eur J Paediatr Dent. 2007 Jun;8(2):89-95.13. Cengiz E, Yilmaz HG. Efficacy of Erbium, Chromium-doped:Yttrium, Scandium, Gallium, and Garnet Laser Irradiation Combined with Resin-based Tricalcium Silicate and Calcium Hydroxide on Direct Pulp Capping: A Randomized Clinical Trial. J Endod 2016 Mar;42(3):351-355. 14. Silva M, Vieira L , Sobrinho A, Horizonte B.The effects of mineral trioxide aggregates on cytokineproduction by mouse pulp tissue. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008 May;105(5):e70-76.15. Zhao Y, Wang CL, Li RM, Hui TQ, Su YY, Yuan Q, Zhou XD, Ye L. Wnt5a promotes inflammatory responses via nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) pathways in human dental pulp cells. J Biol Chem 2014 Jul 25;289(30):21028-21039.16. Goldberg M, Smith A. Cells and extracellular matrices of dentin and pulp. A biological basis for repair and tissue engineering. Crit Rev Oral Biol Med 2004;15:13-27.17. Kramer P, Woodmansey K, White R, Primus C, Opperman L.Capping a pulpotomy with calcium Aluminosilicate cement:comparison to Mineral Trioxide Aggregates. J Endod 2014; 40:1429-1434.18. Asgary S, Eghbal M, Parirokh M, Ghanavati F, and Rahimi H A comparative study of histologic response to different pulp capping materials and a novel endodontic cement. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;106:609-614.19. Nielsen MJ, Casey JA, VanderWeele RA, Vandewalle KS.Mechanical properties of new dental pulp-capping materials. Gen Dent. 2016 Jan-Feb;64(1):44-8.20. Stefanova VP, Tomov GT, Tsanova STs. Morphological Study Of Border Area Of Pulp-Capping Materials And Er:YAG Laser Prepared Hard Dental Surface. Folia Medica (Medical University of Plovdiv, Bulgaria) 2015 Jan-Mar;57(1):49-55.21. Jayawardena J, Kato J, Moriya K, Takagi Y .Pulpal response to exposure with Er:YAG laser Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001;91:222-229.22. Komabayashi T, Ebihara A, Aoki A. The use of lasers for direct pulp capping. J Oral Sci 2015;57(4):277-286.23. Poggio C , Beltrami R , Colombo M, Ceci M, Dagna A, Chiesa M .In vitro antibacterial activity of different pulp capping materials. J Clin Exp Dent 2015 Dec 1;7(5):e584-588.24. Shiba H. Tsuda H, Kajiya M. et al. Neodymium-doped Yttrium-Aluminium-Garnet Laser Irradiation Abolishes the Increase in Interleukin-6 Levels Caused by Peptidoglycan through the p38 Mitogen-activated Protein Kinase Pathway in Human Pulp Cells J Endod 2009 Mar;35(3):373-376.25. Ferreira DC, Brito DG, Cavalcanti BN. Cytokine production from human primary teeth pulp fibroblasts stimulated by different pulpotomy agents. J Dent Child (Chic) 2009 Sep-Dec;76(3):194-198.

Corresponding author:Cynthia Kassis [email protected]




maxillo-facial procedures. Initial search resulted in 62 articles, 19 of which met the inclusion criteria (Table 2). Five articles were excluded due to quality/availability lack of randomization. Due to the high heterogeneity, results are presented in a narrative format.

RESULTS AND DISCUSSIONL-PRF in the treatment of periodontal intra-bony defects (IBDs).

Periodontal tissue regeneration is the formation of new cementum, alveolar bone, and a functional periodontal ligament on a previously-diseased tooth-supporting root surface. Due to limited intrinsic regenerative potential, IBDs are a common and challenging sequel of chronic periodontal disease. Meta-analyses demonstrated that treatment with conservative open flap debridement produces an average clinical

attachment gain of 2.0mm9. While about 1.5mm may be attributed to newly formed bone; bone-fill does not implicate the regeneration of new attachment to the root9. In this context, L-PRF appears promising for regeneration of the whole periodontal attachment system (Figs. 3A, 3B). Five RCTs addressing the prospective application of L-PRF in the treatment of periodontal IBD were found. Identified studies allowed for the following comparisons: (a) L-PRF/open flap surgery vs. open flap surgery10-12, (b) L-PRF/Bio-Oss® constructs (Bio-Oss®, Geistlich Pharma North America, Inc.) vs. L-PRF13 and (c) L-PRF/DFDBA constructs vs. DFDBA (Demineralized Freeze-Dried Bone Allograft)14. All patients included in those studies were periodontally-stable and systemically healthy individuals who presented: similar bilateral IBDs of at least 5mm probing depth, in relation with vital

Fig. 1. L-PRF Clinical Presentation and Composition/Architecture Illustration.

Fig. 2. Flow-Chart of Literature Search Strategy and Results.

debated to date. This is mainly due to mixed/variable clinical outcomes, limited high-quality evidence-based literature, and poor characterization of end-products (and preparation protocols) used in studies, and - until recently - lack of proper terminology systems to classify these preparations4. Indeed, the first “classification” consensus5 was published in 2009, describing 4 different platelet concentrate sub-families, based on variability in biological content (fibrin and cell), properties (gelification) and potential applications: Pure Platelet-Rich Plasma (P-PRP), Leukocyte and Platelet-Rich Plasma (L-PRP), Pure Platelet-Rich Fibrin (P-PRF) and Leukocyte and Platelet-Rich fibrin (L-PRF)5. Nowadays, it can be safely stated that, in oral and maxillofacial surgery, the L-PRF sub-family4-6 is receiving the most attention, mainly due to simplicity, user-friendliness and cost-effectiveness, when compared to the PRPs.

L-PRF is a second generation autologous platelet concentrate of whole venous blood4,6. A slowly- and strongly-polymerized fibrin gel (Fig. 1) rich in growth factors, platelets, leukocytes (almost half of the initial blood harvest) and lymphocytes, is collected, following rapid (~10 minutes) centrifugation of blood (note that preparation protocols vary - see Table 1), in vacutainer tubes, without anti-coagulant. The gathered clot (or biomaterial) is stable, resilient, strong, adhesive and

malleable, where it can be cut or adapted into different anatomical defects and applications (used directly as filling material, mixed with bone grating material, or compressed into a strong fibrin membrane). Alongside this established clinical ease of use and handling, biochemical composition of L-PRF by-products provides it with attractive hemostatic, angiogenic, osteogenic, anti-inflammatory, anti-microbial, pain-inhibitory and wound healing characteristics3,7,8.

This critical review aims to provide readers with an evidence-based presentation on the evaluation of L-PRF use and application in periodontal and jaw tissue regeneration, from randomized and controlled clinical trials. Thus, in vitro, in vivo, and case report studies were excluded from our analysis.

REVIEW METHODA structured literature search (Fig. 2) was performed

on PubMed (October 2015 to February 2016) using MeSH terms “Platelet-rich fibrin” and “Platelet-rich plasma” according to the following search strategy: “Platelet-rich fibrin” [All Fields] NOT “Platelet-rich plasma” [All Fields]. Results were limited by: Seniority (5 years since publication), Language (English), Availability (Full-text) and Species (Human). Inclusion criteria were: (a) randomized controlled trials (RCTs) using (b) Choukroun’s L-PRF (not PRF) in (c) oro-

Table 1. Recommendations for L-PRF preparation.


gain and KTW increase in all L-PRF-treated sites vs. controls. Interestingly, post-treatment GMS was also higher in the test group with 100% root coverage after 6 months vs. 64.88% in controls18. However, in contrary with this RCT, Aroca and co-workers19 reported limited clinical benefits when using the L-PRF/CAF approach19. Herein, clinical average attachment level gain and gingival tissue thickness (GTT) were the only benefiters of the combination; whereas percentage of root coverage, full root coverage, GMS, and recession width (RW) reduction were significantly higher in CAF-alone controls than the test group19. Such “contradictory” results may be partially explained by a deficient study design, which, not only failed to adequately include blind examiners (leading to potential bias in favor of the “traditional” approach), but also included: multiple adjacent gingival

recessions (with poorer prognosis than single/localized recessions), heavy smokers (in which healing response is usually altered), and the storage of L-PRF in a 4°C refrigerator until use (L-PRF protocols often recommend immediate/fresh use). Indeed, emerging evidence states that growth factor release from L-PRF initiates as early as 5 minutes from preparation/centrifugation. Hence, storage could have altered its properties and thereby diminished or deteriorated its clinical potential. When compared to other root coverage procedures (EMD/CAF, CTG and SCTG), the L-PRF/CAF approach showed similar clinical outcomes regarding RD reduction, clinical average attachment level gain, mean root coverage and complete root coverage. KTW increase was the only exception, with both EMD/CAF and CTG controls showing higher KTW than L-PRF-treated groups20-22.

Fig. 3. Clinical illustrations of L-PRF applications in oral and periodontal defect regeneration: natural guided tissue bio-engineering using L-PRF as a “bio-scaffold”.

3A. L-PRF membrane preparation. 3B. Clinical application in IBD. 3C. Clinical application in PAOO.

asymptomatic teeth with no furcation involvement. Studies evaluating the addition of L-PRF to conventional open flap procedure reported that the biomaterial notably improved both, clinical and radiographic parameters of IBDs, after 911,12 and 12 months10. A significant increase in probing depth (PD) reduction, clinical average attachment level gain, post-treatment gingival margin stability (GMS) [less post-treatment gingival recession], bone defect fill and percentage bone defect fill were noticed in all L-PRF-treated sites v/s. controls10-12. Interestingly, higher patient acceptance was also associated with use of L-PRF. Most probably, this is attributed to the accelerated wound healing and pain-inhibitory properties10,11. PD reduction and clinical average attachment level gain values were superior to previously-reported values in meta-analysis performed for open flap surgery9, suggesting the additional benefits of L-PRF over the conventional approach. Treatment with L-PRF/particulate bone-graft substitutes (Bio-Oss®13 and DFDBA14) provided additional statistically-significant benefits, in terms of PD reduction, clinical average attachment level gain and bone defect fill vs. graft substitutes, after 6 months. Nonetheless, the absence of “simultaneously-run” L-PRF-alone control renders it difficult to distinguish between the effects of L-PRF and other potential variables in the study. Thus, while results are promising, additional studies are deemed essential in order to appropriately determine (quantifiably) the effectiveness and advantages of L-PRF application over particulate bone-grafts use.

L-PRF in the treatment of periodontal furcation defects (PFDs)

Molars with furcation involvement (resulting from periodontitis) have higher rates of periodontal breakdown and poorer prognosis, than single-rooted teeth15. Contemporary treatment options often include the use of regenerative materials and bone grafts; however, introduction of L-PRF seems promising for better therapeutic outcomes. In our analyses, 1 RCT addressing the therapeutic use of L-PRF in PFDs was found16. The study compared L-PRF/open flap vs. open flap debridement alone, in the treatment of grade II mandibular defects. Included patients were periodontally-stable and systemically healthy, with similar bi-lateral grade II buccal furcation defects (at least 5mm probing

depth and >3mm horizontal probing depth), in vital asymptomatic mandibular first molars.

L-PRF use significantly improved clinical and radiographic parameters of conventional open flap debridement. After 9 months, complete clinical closure of the defect was achieved in 66.7% of L-PRF-treated sites. Severity within residual defects was reduced in 5/6 sites (degree I), whereas one defect remained in degree II. Significantly greater PD reduction, clinical average attachment level gain and radiographic vertical defect fill was reported on experimental sites vs. controls. L-PRF use was also associated with a greater post-treatment GMS16.

L-PRF in the treatment of Miller's Class I and II gingival recessions

Gingival recessions are characterized by apical migration of gingival margin with subsequent root surface exposure. If left untreated, this condition may lead to other problems including: deficient esthetics, dentine hypersensitivity and higher risk of dental caries17. Available treatment options include the use of: (a) Coronally-Advanced Flaps (CAF); (b) Connective Tissue Grafts (CTG); and (c) Sub-epithelial Connective Tissue Grafts (SCTG). On their own, the aforementioned techniques have important limitations such as (a) unpredictable long-term root coverage (i.e. CAF decreases from 89% to 58.8% after 6 months), (b) limited gain of keratinized tissue width (KTW) (important to prevent recurrence), and (c) adverse post-surgical effects such as pain/discomfort, swelling, flap necrosis, etc.17. In this review, five RCTs evaluating the application of L-PRF in the treatment of gingival recessions were included. These studies allowed for the following comparisons: (a) L-PRF/CAF vs. CAF18-19; (b) L-PRF/CAF vs. EMD (Enamel Matrix Derivatives)/CAF20; (c) L-PRF/CAF vs. CTG21; and (d) L-PRF/CAF vs. SCTG22. Similar to previous RCTs, all patients included herein were periodontally-stable and systemically healthy; they presented with: similar bilateral Miller's Class I or II gingival recessions (>2mm depth) localized on vital teeth without restorations. According to Padma and associates18, addition of L-PRF to CAF improved both, clinical outcomes and post-treatment stability of CAF18. After 6 months, authors reported significantly more recession depth (RD) reduction, clinical average attachment level


Tabl

e 2.

Sum

mar

y of

lite

ratu

re (R

CTs

) on

L-PR

F us

e in

den

tistry

(Par

t I).

Interestingly, all studies reported significantly faster healing and fewer complications (pain and discomfort) when L-PRF was used20-22. Findings were notable, especially when compared with SCTG (the current “gold standard” technique for treating Miller's Class I and II gingival recessions), indicating that L-PRF/CAF could be a safer and less invasive alternative to current grafting techniques and a more cost-effective strategy or approach than EMD is in treating Miller's Class I and II gingival recessions (Fig. 3C).

L-PRF in maxillary sinus floor augmentation

Resorption of maxillary bone after tooth loss is a frequent problem faced in posterior maxillary implant placement due to lack of sufficient bone mass for anchorage. Common maxillary sinus floor augmentation techniques provide a solution via increasing the available bone height at the expense of sacrificing volume of the maxillary sinus23. Traditionally, autologous bone grafts and resorbable membranes are used to promote osteogenesis and avoid soft tissue in-growth into the surgical site. However, donor site morbidity and size restrictions, latter resorption of the graft and high-cost of membranes, are main disadvantages24-25. In this context, L-PRF appears to provide a promising alternative overcoming such limitations. In this review, two RCTs evaluating the use of L-PRF in lateral window maxillary sinus augmentation were found. Applications were performed either as: (a) grafting material (L-PRF/Bio-Oss® constructs vs. Bio-Oss®)26 or (b) absorbable covering membrane for the lateral osteotomy window (L-PRF vs. Geistlich Bio-Gide®)27. In both studies, included subjects were systemically healthy adults with maxillary atrophy (defined as <5mm residual bone crest height measured in OPG/orthopantomogram). Smoking status was not assessed. The addition of L-PRF to Bio-Oss® bone-substitute revealed neither advantages nor disadvantages over Bio-Oss®-alone controls26. After 6 months, clinical and radiographic examinations revealed both groups exhibiting similar amounts and density of mineralized tissues, with no signs of material resorption. Histological evaluations also showed non-significant differences regarding: (a) percentage of newly formed bone, (b) percentage of residual Bio-Oss®, (c) bone-to-bone-substitute contact, and (d) post-treatment inflammatory

reactions26. Regarding coverage of lateral osteotomy sinus window, L-PRF use resulted in a similar amount of vital bone formation (%) and residual bone-substitute when compared to Bio-Gide® controls (L-PRF: 17.0% and 15.9%, Bio-Gide®: 17.2% and 17.3%, differences were not statistically-significant). Overall, despite a slightly superior to no coverage at all (12.1%), it can be stated that results were similar to those reported using other conventional membranes (collagen: 17.6%; e-PTFE: 16.9%)27. Within the presented limitations in both RCTs, evidence suggests that L-PRF is a safe, simple to use and handle, and cost-effective alternative to traditional bone grafts and absorbable membranes in low-income patients pursuing maxillary sinus augmentation procedures.

L-PRF in alveolar ridge preservationPost-extraction changes in alveolar bone

compromise prosthodontic rehabilitation with fixed, removable and/or implant-supported prosthesis. Alveolar ridge preservation (ARP) is a technique which involves the use of grafting and barrier materials in order to significantly reduce post-extraction bone loss28. L-PRF has been demonstrated to accelerate/enhance bone repair29,30, promote fibroblast proliferation3,30 and increase vascularity31, thereby, potentially favoring the post-extraction healing process and the ARP approach. Yet a single RCT evaluating the use of L-PRF in ARP was identified, according to the inclusion criteria set herein32. This sole study compared the application of L-PRF vs. natural blood clots in post-extraction sockets of third molars. Patients were systemically healthy and non-smoking adults requiring bilateral mandibular third molar removal. The use of L-PRF significantly improved post-extraction soft tissue healing after 7 days32. Early and significantly-higher radiographic bone formation/maturation was noticed in the L-PRF treated sites vs. controls, at 8 weeks. By 12 weeks, inter-group differences were non-significant. Radiographic bone density (measured by gray scale value) at 12 weeks increased in the biomaterial group compared to controls; nonetheless, the differences were not significant32. Similar to other studies, L-PRF reduced early post-surgical pain (on visual analog scale - VAS) on day 1; however, inter-group differences were not significant by day seven32.


Personal expertise–L-PRF in periodontally accelerated osteogenic orthodontics (PAOO)

In our own pilot prospective observational study30 involving a cohort of 11 patients (with informed consent) receiving a Wilcko’s modified PAOO (Periodontally Accelerated Osteogenic Orthodontics = a surgical procedure which allows faster tooth movement via combining orthodontic forces with corticotomy and grafting of alveolar bone plates) technique with L-PRF (incorporated into the graft and as covering membrane), accelerated wound healing with no signs of infection or adverse reactions was evident (Figure 3D). Post-surgical pain, inflammation and infection were recorded for 10 days post-operatively, while overall orthodontic treatment and post-treatment stability were followed up to 2 years. In our data analysis, post-surgical pain was found to be either “mild” (45.5%) or “moderate” (54.5%); immediate post-surgical inflammation was recorded as either “mild” (89.9%) or “moderate” (9.1%); and, resolution was marked to begin on day 4 where most patients experienced either “mild” or no inflammation (72.7% and 9.1%, respectively). Interestingly, complete resolution was achieved in all patients by day 8, the average orthodontic treatment time was calculated at 9.3 months and all cases were stable throughout. Thus, we concluded that combining L-PRF with traditional bone grafts (L-PRF plug or block) potentially accelerates wound healing and reduces post-surgical pain, inflammation and infection without interfering with tooth movement and/or post-orthodontic stability, over an extended 2-year observational period; thereby alleviating the need for analgesics and anti-inflammatory medications30.

CONCLUSIONS Tissue regeneration and anatomical reconstruction

of periodontal and jaw defects have always been a critical and controversial issue. Both, quality and quantity of the regenerated tissues are important to consider, esthetically and functionally. Practically, oral and periodontal surgeons are faced with an ample collection of regenerative techniques and materials to choose from. How can one select the “ideal” or “best-fit” strategy and procedure for an optimal clinical outcome? Evidence-based studies? Level of evidence? To the best of our knowledge, this is the first review

of randomized controlled clinical trials on L-PRF use and application in Oral Surgery. While the available literature is found to be highly-limited, L-PRF can be considered as an innovative tool for contemporary oro-maxillo-facial tissue regeneration and bioengineering. Indeed, existing evidence suggests that L-PRF improves early wound healing and promotes post-surgical bone formation/maturation. However, it is noteworthy that a clearer consensus seems to be present regarding its significant beneficial impact on post-surgical pain and discomfort control, regardless the type of procedure. Unlike its predecessors, new L-PRF preparations tend to function more as biologically-active biomaterials and scaffolds for the delivery of autologous cells, cytokines and growth factors. Thus, L-PRF should be considered a “living tissue” preparation for natural guided tissue regeneration and not simply a “growth factor-rich” surgical adjuvant. Yet it is safe to say that this remains an unexplored territory in Dental Biomaterials (Dental BioEngineering) Research, in general. Our group is currently investigating the potential of incorporating oral-derived mesenchymal stem cells or growth-factor embedded nanoparticles within the L-PRF, as “super” or “smart” bio-scaffolds, to further boost, with predictability, bone formation, soft tissue healing, treatment time and post-surgical stability, in advanced oral and periodontal surgical procedures such as PAOO. Our research extends to investigate the potential of L-PRF in reducing the need for drug use following invasive surgical procedures such as third molar extraction and cysts enucleations. Finally, we are vigorously working on characterizing the rheological and biological variations of L-PRF, alongside partnering up with nurses, physicians, and dentists in order to standardize the preparation protocol, for use in other therapeutic indications.

Acknowledgements: This work was supported by generous funding and operating grants provided to the BioMAT’X Research Group, part of CIIB (Centro de Investigacióne Innovación Biomédica), through the Faculty of Dentistry and PMI (Plan de Mejoramiento Institucional en Innovación I+D+i), Department for Research, Development and Innovation, Universidad de Los Andes, Santiago de Chile, and CONICYT-FONDEF Chile grant ID#16l10366. Special acknowledgement

Tabl

e 2.

Sum

mar

y of

lite

ratu

re (R

CTs

) on

L-PR

F us

e in

den

tistry

(Par

t II)

.


25. Van den Bergh JP, Bruggenkate CM ten, Krekeler G, Tuinzing DB. Sinusfloor elevation and grafting with autogenous iliac crest bone. Clin Oral Implants Res. 1998;9(6):429-435.26. Zhang Y, Tangl S, Huber CD, Lin Y, Qiu L, Rausch-Fan X. Effects of Choukroun’s platelet-rich fibrin on bone regeneration in combination with deproteinized bovine bone mineral in maxillary sinus augmentation: A histological and histomorphometric study. J Cranio-Maxillofac Surg 2012;40(4):321-328. 27. Gassling V, Purcz N, Braesen J-H, Will M, Gierloff M, Behrens E, et al. Comparison of two different absorbable membranes for the coverage of lateral osteotomy sites in maxillary sinus augmentation: A preliminary study. J Cranio-Maxillofac Surg 2013;41(1):76-82. 28. Hämmerle CHF, Araújo MG, Simion M, Osteology Consensus Group 2011. Evidence-based knowledge on the biology and treatment of extraction sockets. Clin Oral Implants Res 2012;23 Suppl 5:80-82. 29. Pripatnanont P, Nuntanaranont T, Vongvatcharanon S, Phurisat K. The primacy of platelet-rich fibrin on bone regeneration of various grafts in rabbit’s calvarial defects. J Cranio-Maxillofac Surg 2013;41(8):e191-200. 30. Munoz F, Jiménez C, Espinoza D, Vervelle A, Beugnet J, Haidar Z. Use of leukocyte and platelet-rich fibrin (L-PRF) in periodontally accelerated osteogenic orthodontics (PAOO): Clinical effects on edema and pain. J Clin Exp Dent 2016 Apr 1;8(2):e119-124.31. Chen Y, Niu Z, Xue Y, Yuan F, Fu Y, Bai N. Improvement in the repair of defects in maxillofacial soft tissue in irradiated minipigs by a mixture of adipose-derived stem cells and platelet-rich fibrin. Br J Oral Maxillofac Surg 2014;52(8):740-745. 32. Singh A, Kohli M, Gupta N. Platelet Rich Fibrin: A Novel Approach for Osseous Regeneration. J Maxillofac Oral Surg 2012;11(4):430-434.

Corresponding Author: Ziyad S. [email protected]

is given to Dr. Nelson R. Pinto for kindly providing the SEM micrographs and Dr. Macarena Llompart for kindly providing the clinical photographs for L-PRF use in periodontics (Figs. 3B, 3C).

Conflicts of Interest Disclosure StatementAuthors of this review article declare having no

conflict of interest of any form or nature with any platelet concentrate product, protocol, technique, or company.

REFERENCES1. Habibovic P, de Groot K. Osteoinductive biomaterials—properties and relevance in bone repair. J Tissue Eng Regen Med 2007;1(1):25-32. 2. Haidar ZS. NanoDentistry: Perspectives on the Role of NanoBiotechnology in Biomaterials, Pharmaceutics and BioDental Tissue Engineering. EC Dental Science 2015; 3(2):506-507.3. Dohan DM, Choukroun J, Diss A, Dohan SL, Dohan AJJ, Mouhyi J, et al. Platelet-rich fibrin (PRF): A second-generation platelet concentrate. Part II: Platelet-related biologic features. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;101(3):e45-50.4. Del Corso M, Vervelle A, Simonpieri A, Jimbo R, Inchingolo F, Sammartino G, et al. Current knowledge and perspectives for the use of platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) in oral and maxillofacial surgery part 1: Periodontal and dentoalveolar surgery. Curr Pharm Biotechnol 2012;13(7):1207-1230. 5. Dohan Ehrenfest DM, Rasmusson L, Albrektsson T. Classification of platelet concentrates: from pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF). Trends Biotechnol 2009;27(3):158-167.6. Simonpieri A, Del Corso M, Vervelle A, Jimbo R, Inchingolo F, Sammartino G, et al. Current knowledge and perspectives for the use of platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) in oral and maxillofacial surgery part 2: Bone graft, implant and reconstructive surgery. Curr Pharm Biotechnol 2012;13(7):1231-1256.7. Dohan DM, Choukroun J, Diss A, Dohan SL, Dohan AJJ, Mouhyi J, et al. Platelet-rich fibrin (PRF): A second-generation platelet concentrate. Part III: Leucocyte activation: A new feature for platelet concentrates?. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;101(3):e51-55.8. Bielecki T, Dohan Ehrenfest DM, Everts PA, Wiczkowski A. The role of leukocytes from L-PRP/L-PRF in wound healing and immune defense: new perspectives. Curr Pharm Biotechnol 2012;13(7):1153-1162.9. Lang NP. Focus on intrabony defects – conservative therapy. Periodontol 2000 (2000);22(1):51-58.10. Rosamma Joseph V, Raghunath A, Sharma N. Clinical effectiveness of autologous platelet rich fibrin in the management of infrabony periodontal defects. Singapore Dent J 2012;33(1):5-12.

11. Thorat M, Pradeep AR, Pallavi B. Clinical effect of autologous platelet-rich fibrin in the treatment of intra-bony defects: a controlled clinical trial: Platelet-rich fibrin and periodontal regeneration. J Clin Periodontol 2011;38(10):925-932.12. Sharma A, Pradeep AR. Treatment of 3-wall intrabony defects in patients with chronic periodontitis with autologous platelet-rich fibrin: a randomized controlled clinical trial. J Periodontol 2011;82(12):1705-1712.13. Lekovic V, Milinkovic I, Aleksic Z et al. Platelet-rich fibrin and bovine porous bone mineral vs. platelet-rich fibrin in the treatment of intrabony periodontal defects: Xenograft and platelet-rich fibrin in intrabony defects. J Periodontal Res 2012;47(4):409-417.14. Bansal C, Bharti V. Evaluation of efficacy of autologous platelet-rich fibrin with demineralized-freeze dried bone allograft in the treatment of periodontal intrabony defects. J Indian Soc Periodontol 2013;17(3):361-366.15. Goldman MJ, Ross IF, Goteiner D. Effect of periodontal therapy on patients maintained for 15 years or longer. A retrospective study. J Periodontol 1986;57(6):347-353. 16. Sharma A, Pradeep AR. Autologous platelet-rich fibrin in the treatment of mandibular degree II furcation defects: a randomized clinical trial. J Periodontol 2011;82(10):1396-1403.17. Cortellini P, Pini Prato G. Coronally advanced flap and combination therapy for root coverage. Clinical strategies based on scientific evidence and clinical experience. Periodontol 2000 (2012);59(1):158-184. 18. Padma R, Shilpa A, Kumar PA, Nagasri M, Kumar C, Sreedhar A. A split mouth randomized controlled study to evaluate the adjunctive effect of platelet-rich fibrin to coronally advanced flap in Miller’s class-I and II recession defects. J Indian Soc Periodontol 2013;17(5):631-636. 19. Aroca S, Keglevich T, Barbieri B, Gera I, Etienne D. Clinical evaluation of a modified coronally advanced flap alone or in combination with a platelet-rich fibrin membrane for the treatment of adjacent multiple gingival recessions: a 6-month study. J Periodontol 2009;80(2):244-252. 20. Jankovic S, Aleksic Z, Milinkovic I, Dimitrijevic B. The coronally advanced flap in combination with platelet-rich fibrin (PRF) and enamel matrix derivative in the treatment of gingival recession: a comparative study. Eur J Esthet Dent 2010;5(3):260-273. 21. Jankovic S, Aleksic Z, Klokkevold P, Lekovic V, Dimitrijevic B, Kenney EB, et al. Use of platelet-rich fibrin membrane following treatment of gingival recession: a randomized clinical trial. Int J Periodontics Restorative Dent 2012;32(2):e41-50. 22. Eren G, Atilla G. Platelet-rich fibrin in the treatment of localized gingival recessions: a split-mouth randomized clinical trial. Clin Oral Investig 2014;18(8):1941-1948. 23. Boyne PJ, James RA. Grafting of the maxillary sinus floor with autogenous marrow and bone. J Oral Surg 1980;38(8):613-616. 24. Cordaro L. Bilateral simultaneous augmentation of the maxillary sinus floor with particulated mandible. Report of a technique and preliminary results. Clin Oral Implants Res 2003;14(2):201-206.



Implant Dentistry

INTRODUCTIONDuring the sixties, Boyne1-2 proved, in a dog study,

how the use of a shield to protect blood clot produced regeneration. He also demonstrated how metallic cages could work in association with autogenous marrow and bone graft in the reconstruction of jaw defects.1-2

In 1988, Dahlin and associates3 introduced the use of a teflon membrane to induce regeneration on bony defects in rabbit bones, isolation of the soft tissue from the wound area would result in healing promoted by marrow cells, resulting in new bone formation.3

These concepts have been later applied to human situations whenever a bony defect resulted from extraction, trauma, or periodontal disease. Simion and co-workers4 compared, in a human model, the ability of e-PTFE membranes plus bone chips autografts, ePTFE (expanded polytetrafluoroethylene) membranes plus DFDB (Decalcified Freeze-Dried Bone), ePTFE

membranes plus a new form of DFDB, and ePTFE membranes alone to enhance bone regeneration around dental endosseous implants placed into fresh extraction sockets. Combination of membrane and autogenous bone proved to be the best in producing dense new bone formation4. Fontana and associates5 compared clinically and histologically an allogenic bone matrix to autogenous bone chips in vertical ridge augmentation using titanium reinforced ePTFE membranes. In their study, the two grafting materials proved to be efficient but the deal was the use of a rigid type of membrane supported with a titanium grid.5

The use of non resorbable titanium reinforced membranes became a standard treatment of vertical defects and the literature described all the lights and also all the shadows related to this kind of approach. Fontana and co-workers6 classified the different types of complications related to the use of non-resorbable membranes. They divided the complications in surgical and healing ones6 (flap damage, neurological and vascular complications, complications during healing period, early membrane exposure).

When evaluating a surgical technique, systematic reviews best evaluate its effectiveness. A systematic review done by Rocchietta and associates7 on clinical outcomes of vertical ridge augmentation, concluded

Roberto Rossi1, DDS, CAGS, M.Sc.D, FSidP, MAAP, MESCD, Edoardo Foce2, MD, DDS, Salvatore Scolavino3, DDS, MD

AbstractThe loss of one or more teeth very often causes fuctional and esthetic impairements. Alveolar ridge volumetric

changes after dental extractions can reach up to fifty percent of the original bony volume during the first twelve months. During the past twenty five years, dental community experienced several different surgical procedures for bone and soft tissue regeneration using non resorbable membranes, titanium meshes, and other materials, always associated with bone grafts, in attempt to address this problem. All these procedures, named guided bone regeneration, have demonstrated many limitations and a range of complications, all well documented in the literature.

The Cortical Lamina technique uses a curved collagenated bony plate which has characteristics that make the surgery easy and predictable. This paper describes the protocol used in a multicenter study aimed to show the predictability and validity of this relatively new approach.

1. Private practice, Genoa, Italy,Visiting Professor of Periodontology and Implant Dentistry, Masters Programs in Dental Implantology, Universities of Rome and La Sapienza, Italy,Clinical Associate Professor of Periodontology, LUDES Higher Education Institute, Smart City, Ricasoli SCM, Malta2. Former Lecturer, San Raffaele Hospital, Department of Periodontology, Milano, Italy,3. Esthetic and Restorative Dentist, Member of the StyleItaliano group, Private Practice in Nola, Italy.

The Cortical Lamina technique: A new option for alveolar ridge augmentation. Procedure, protocol, and case report.



implant with a good prosthetic axis.Case study is done also on stone casts in order to

evaluate several important parameters:1- Ridge width and discrepancy (Fig. 4).2- Inter arch space. 3- Occlusion.After completing all preliminary measurements,we

can proceed with our plan to change anatomy of the area from concave to convex, thus augmenting the volumes in both dimensions.

Surgical ProcedureLocal analgesia is administered with local infiltration

of articaine 2% with adrenaline 1:200.000. Incisions are made with a 12C blade to split the available keratinized gingiva and full-thickness buccal and lingual flaps are raised to expose the underlying anatomy.

We can see the series of steps in fig. 5: once the flaps are reflected and the bone exposed, the cortical lamina is trimmed, bent, and adjusted to local anatomy.

A very important issue is to keep the lamina dry in order to preserve its stiffness. Because of its flexibility and elasticity, cortical lamina doesn't need to be stabilized with pins or screws, which makes this procedure easier and faster for dentists. Indeed, curved lamina is hard but also flexible and has a good elastic memory. Once activated, it works like a clip on the underlying residual bone. It is very important to mobilize the flaps (buccal and lingual) only at this stage, to make sure that it is possible to achieve a passive closure (of the flaps) and avoid any tension. After these steps are completed, perform intra marrow penetrations on the recipient site to stimulate bleeding from marrow spaces. Once this step is completed, a cortico-cancellous bone graft (hydrated with the patient’s own blood clot) will be placed to fill the edentulous area for augmentation. In fig. 5, one can see the amount of augmentation under a periodontal probe (last picture on the right).

In fig. 6, we can see the grafted area covered with the cortical lamina. The next step is to secure the flaps on top of the lamina with resorbable horizontal mattress sutures. After the procedure is completed, we can see the completely ‘new’ and different anatomy of the quadrant.

Cortical lamina works like a resorbable membrane, but actually integrates in the area where it is placed and at the time of re-entry, we can find sound bone. Six months

after surgery, a CT scan shows the anatomical changes of the area and a more manageable situation (Figs. 7,8,9). The ridge is now wide and has a completely different anatomy as compared to baseline. And after these changes in the augmented area, the placement of two endosseous implants of standard diameter and length is now possible.

At re-entry, the placement of periodontal probe on top of regenerated bone shows a width of 6-7 mm on bucco-lingual aspect and a normal quality of bone. Two standard diameter implants are then placed and primary stability is evaluated using ISQ* scale. The decision was anyway to let the implant rest for at least 90 days before performing second stage (Fig 10).

At day 90, implants were exposed and a mucogingival procedure of soft tissue augmentation was performed to optimize and protect the augmented area. A free gingival graft was harvested from mandibular retromolar area and sutured on buccal aspect of the implants (Fig 11).

Fig. 12 shows the changes in volume on the stone cast before surgery and after final restoration is removed from master cast, and also the radiograph depicting the final restoration in place.

Success of the procedure in augmenting the area is shown in comparing before and after completion of the augmentation and the final restoration in place.

We achieved not only hard and soft tissue augmentation but also a natural emergence profile and a very natural looking restoration (Figs.13a, 13b).

At a recall appointment, 18 months after, a final restoration was placed in function. Fig. 14 shows a perfect stability of soft and hard tissue complex suggesting that the cortical lamina technique should be considered as a possible therapeutic option for this kind of clinical situation.

RESULTSBone lamina technique employs a partially

demineralized cortical, xenogenic, lamella to reconstruct cortical plate. Careful planning, good patient’s selection, and adequate use of biomaterials allow us to achieve good and predictable results.

The use of cortical lamina has been now going on for more than five years13,14 and the results we are collecting are very encouraging. The lamina represents a bone graft

* ISQ = Implant Stability Quotient = is a scale from 1 to 100 and it indicates the level of stability and osseointegration of dental endosseous implants.

that the generalizability of the approach was limited.7 In their review, authors evaluated guided bone regeneration, distraction osteogenesis, autogenous block onlay bone grafting, and an array of different techniques. It was clear that this approach cannot be standardized because of the very variable anatomy.

Nevertheless, Urban and co-workers8 published a study in which 19 patients underwent the use of new titanium reinforced non resorbable membranes (high density PTFE), in combination with a mixture of anorganic bovine bone derived mineral and autogenous bone. In this study, authors established that the vertical limit was 5,45 mm (standard deviation 1.93 mm) and in their population, all patients healed uneventfully and this technique was considered successful.8

Complications described in the study of Fontana6 are a reality we cannot hide, and therefore, alternative options need to be introduced in an attempt to reduce failures and complications.

Pagliani and associates9 introduced a new technique utilizing a different kind of barrier with completely different characteristics from the one proposed before in the literature. They introduced a porcine bone substitute called Cortical Lamina: in their study, they utilized it for augmenting the maxillary sinus floor while placing endosseous dental implants. They reported 94,7% success rate for their implants as one of the 34 implants failed. Histological evaluation of the use of this barrier showed that the material resorbes with time and gets replaced with bone.9

Happe and Slotte10 showed the versatility of the cortical lamina as a mean for horizontal ridge augmentation. Wachtel and associates11 also reported a large number of cases treated by mean of the cortical lamina of different situations where ridge augmentation was required.

Another option proposed in the literature was the use of block graft, autologous and heterologous. In case of autograft, it is necessary to have a harvesting site, creating two surgical sites and an extra discomfort for the patient and more risks of morbidity. To avoid the latter, it is possible to use grafts which have been prepared by companies and sterilized. In both cases, addition of fixation screws becomes mandatory to stabilize the blocks.12-13

CASE REPORTThe cortical lamina is a collagenated porcine bone

graft, prepared by Tecnoss (Giaveno, Torino, Italy), it is delivered sterile and packaged for use. Cortical lamina is made in different versions, thin, curved and straight, offering several surgical options in cases of horizontal or vertical bone augmentation.

We will forcus here on the case study and surgical protocol for combined horizontal and vertical augmentations.

Patient is a 60 year-old female requiring 2 endosseous implants to replace the missing mandibular right molars. We can observe the presence of a knife edge ridge and both horizontal and vertical collapse (Fig. 1).

Anatomy is depicted in the CT scan, with lack of bone in the areas where implants should be placed (Figs. 2-3).

In fig. 2, we can see how the anatomy of the crest is concave and unfavorable to the placement of a dental

Fig. 1

Fig. 2

Fig. 3


Fig. 8

Fig. 10

Fig. 11

Fig. 9

Fig. 12

Fig. 4

Fig. 7

Fig. 5

Fig. 6


7. Rocchietta I, Fontana F, Simion M. Clinical outcomes of vertical bone augmentation to enable dental implant placement: a systematic review. J Clin Periodontol 2008 Sep;35(8 Suppl):203-215.8. Urban I, Lozada JL, Jovanovic SA, Nagursky H, Nagy K. Vertical ridge augmentationwith titanium reinforced, dense-PTFE membranes and a combination of particulated autogenous bone and anorganic bovine bone derived mineral: a prospective case series in 19 patents. Int J Oral Maxillofac Implants 2014 Jan-Feb:29(1):185-939. Pagliani L, Andersson P, Lanza M, Nappo A, Verrocchi D, Volpe S Sennerby L. A colagenated porcine bone substitute for augmentation at Neoss implant sites: a prospective 1-year multicemtric case series study with histology. Clin Implant Dent Related Res 2012 Oct;14(5):746-74910. Happe A, Slotte C. Reconstruction of horizontal defects. Bone, Biomaterials and Beyond. EDRA 2014 (Edited by Antonio Barone and Ulf Nannmark).11. Wachtel H, Helf C, Thalmair T. The bone lamina technique: a novel approach of bone augmentation. Bone Biomaterials and Beyond. EDRA 2014 (Edited by Antonio Barone and Ulf Nannmark).12. Nannmark U, Sennerby L. The bone tissue responses to prehydrated and collagenated corico-cancellous porcine bone grafts: a study in rabbit maxillary defects. Clin Implant Dent Relat Res 2008; 10 (4):264-270.13. Wachtel H, Fickl S, Hinze M, Bolz W, Thalmair T. The bone lamina technique: a novel approach for lateral ridge augmentation - a case series. Int J Periodontics Restorative Dent 2013 Jul-Aug;33(4):491-497.14. Lopez MA, Andreasi Bassi M, Confalone L, et al. The use of resorbable cortical lamina and micronized collagenated bone in the regeneration of atrphic crestal ridges: a surgical technique. Case series. J Biol Regul Homeost Agents 2016. Apr-Jun;30(Suppl 1):81-85.15. Deepika-Penmetsa SL, Thomas R, Baron TK, Shah R, Mehta DS. Cortical lamina technique: A therapeutic approach for lateral ridge augmentation using guided bone regeneration. J Clin Exp Dent 2017 Jan 1;9(1):e21-e26.

Corresponding author:Roberto [email protected]@ludes.edu.mtwww.drrossi.com

itself and its passive placement already augments any area. Addition of a particulate bone graft provides blood supply and cells under the lamina and flaps provide a proper blood supply on top and the whole complex heals uneventfully.

DISCUSSIONLiterature on guided bone regeneration has proposed

many different techniques and biomaterials during the past twenty years to solve the problem of edentulous resorbed ridges. From PTFE membranes, to titanium meshes, to block grafts, options for clinicians are numerous. It is also known that limitations of the above-mentioned techniques and the complications related to them are also well documented in the literature. The use of a porcine collagenated cortical lamina with a thickness of 0.9 mm allows to use a rigid, moldable, and adjustable membrane that is actually made of bone and adapts well to local anatomy in edentulous mandible or maxilla. In our experience, this technique can safely reconstruct alveolar ridge defects, improving and bypassing many of the limitations related to alternative techniques. The case presented here is part of a large international ongoing multicenter study that aims to evaluate volumetric changes before and after lamina placement, histomorphometrically assess bone healing, and evaluate long-term success of dental endosseous implants inserted into these reconstructed areas.

The bone lamina technique combines the stability found in non-resorbable membranes with the biodegradation found in collagen membranes. In combination with a resorbable bone substitute, the lamina technique is an interesting and attractive approach to biological regeneration of alveolar ridge defects in implant dentistry.

Recently, an academic group of Indian periodontists and oral implantologists published a study15 in which

they addressed the cortical lamina technique as a possible therapeutic approach for lateral ridge augmentation: they used a mineralised, allogenic, cortical shell of 1 mm thickness, particulate xenograft, and resorbable collagen membrane, on horizontal ridge defects in 10 patients. They demonstrated that bone lamina technique can be an effective means of horizontal ridge augmentation, leading to a good amount of bone regeneration for subsequent implant placement15.

Further studies are warranted to confirm the efficacy of this technique and its future applications as an everyday surgical option.

ACKNOWLEDGEMENTSWe would like to thank Tecnoss (Giaveno, Torino,

Italy) and Drs. Giuseppe and Davide Oliva for their continuous commitment for developing new biomaterials.

REFERENCES1. Boyne PJ. Regeneration of alveolar bone beneath cellulose acetate filter implants. J Dent Res 1964;43:827.2. Boyne PJ. Restoration of osseous defects in maxillofacial casualties. J Am Dent Assoc 1969;78:767.3. Dahlin C. Lindhe A. Gottlow J. Nyman S. Healing of bone defects by guided tissue regeneration. Plast Reconstrts Surg 1988 May;81(5):672-676.4. Simion M, Dahlin C, Trisi P, Piattelli A. Qualitative and quantitative comparative study on different filling materials in bone tissue regeneration: a controlled clinical study. Int J Periodontics Restorative Dent. 1994 Jun;14(3):198-215.5. Fontana F, Santoro F, Maiorana C, Iezzi G, Piattelli A, Simion M. Clinical and histological evaluation of allogenic bone matrix versus autogenous bone chips associated with titanium reinforced ePTFE membrane for vertical ridge augmentation: a prospective pilot study. Int J Oral Maxillofac Implants 2008 Nov-Dec;23(6):1003-1012.6. Fontana F, Maschera E, Rocchietta I, Simion M. Clinical classification of complications in guided bone regeneration procedures by means of non resorbable mebranes. Int J Periodontics Restorative Dent 2011 Jun;31(3):265-273.

Fig. 13a Fig. 13b Fig. 14



CAN TREATMENT RESPONSE CONFIRM THE DIAGNOSIS OF TN?

The first line recommended medications for TN include frequency-dependent sodium channel blockers such as carbamazepine (Tegretol®, a drug used in epilepsy and bipolar disorder) and oxcarbazepine (Trileptal®, Oxtellar XR®, an anticonvulsant primarily used to treat epilepsy, but also used an add-on therapy for bipolar disorder); these drugs were shown to reduce pain in 90% of patients13,14. Thus, a response to these medicines might be considered as a supporting criterion of TN. Despite that, there are no standardized criteria for partial versus complete pain relief. Additionally, these medications may not be well tolerated by certain patients. Therefore, the inclusion of response to medications as a diagnostic criterion is not currently valid3.

For etiologically established TN, two subcategories comprise this entity: classical and secondary TN with an underlying etiology15. Both entities are known as neuropathic pains. However, in a very small proportion of patients with a clinically established TN, investigations fail to show conclusive etiology; the condition will then be defined as idiopathic TN.

Classical TN: Magnetic Resonance Imaging – MRI - demonstration of a vascular compression of trigeminal nerve root along with morphological changes is required for a diagnosis of this category. Other imaging modalities (such as advanced MRI techniques) are now being assessed for a better detection of trigeminal nerve neurovascular compression. Such tools may have a predictive value for neurosurgical intervention16.

Secondary TN: Diagnosing secondary TN entails a demonstration of a neurological disease causing the neuralgia. The majority of tumors (such as cerebellopontine angle tumors) causing TN are benign, and when malignant tumors cause trigeminal pain, pain attacks are not similar to the ones experienced in classical TN. TN occurs in 2%-5% of patients with multiple sclerosis; conversely, multiple sclerosis is detected in 2%-15% of patients with TN4,17,18.

The proposed novel classification will be reflected in the upcoming revision of the World Health Organization’s International Classification of Diseases (WHO ICD), and it is designed to help in diagnostic decisions and treatment guidelines (also see diagram in Fig. 1)3.

RESEARCH AT BASIC SCIENCE LEVEL: LINK BETWEEN PAIN AND THE BRAIN

Chronic pain has been shown to correlate with morphological and functional changes in the brain20. Accordingly, it has been argued that chronic facial pain of somatic or visceral is a neurological disease with neurophysiological biomarkers encompassing a functional anatomical map referred to as a ‘pain neuromatrix’21,22. However, nearly two decades after introducing the concept of neuromatrix, little progress has been made in understanding the dynamic and state-dependent processing of nociceptive information in the brain.

Authors of this letter are of the opinion that conventional pain research is biased towards the study of single-unit electrophysiology in the anesthetized state, and we here argue that in order to make a meaningful advancement, the field needs to move towards characterizing emergent properties of multi-unit ensembles in the awake state.

Of relevance, electroencephalography - EEG - (which is the measurement of brain electrical activity and its recording) fits the bill perfectly in animal and human studies. It allows cost-effective, non-invasive, practical, high-speed, and high-throughput recording of neuronal activity which could be critical for informing optimal treatment protocols while conserving tremendous resources on patient and caregiver23.

BRAIN WAVES AND QUANTITATIVE EEG

Sampled at high frequencies (~3-3,000 Hz), EEG far exceeds the temporal resolution of most imaging techniques. Local field potential - LFP - in the EEG reflects postsynaptic potentials and spiking activity24. Rather than investigating the analogue or ‘raw’ EEG waveforms, quantitative analysis is applied to transform signals from temporal domain to frequency domain, mainly using the Fourier transform algorithm. Although earlier EEG studies focused on skin-evoked responses, the effect of long-term tonic pain on brain oscillation, especially toothache, has not been well characterized. In patients with somatic neuropathic pain, EEG power is increased and dominant frequency is slowed25,26. These changes have been reverse-translated in animal models and were attenuated following effective

TRIGEMINAL PAIN DIAGNOSIS: WHAT’S THE PATIENT SAYING?

The diagnosis of trigeminal neuralgia - TN - is based primarily on patient’s verbal report (pain severity, quality and temporal frequency of attacks) and secondarily, on imaging techniques. However, verbal report and imaging are seldom related. Furthermore, communication between patient and healthcare professional is a subjective process, especially in the case of long-term pain associated with co-morbid cognitive conditions, leading to ambiguous diagnostic criteria that could undermine treatment strategies, compromise clinical outcome, and reduce patient satisfaction. Such is the case for TN, including orofacial pain and several pain conditions of visceral or somatic origins below the neck. To overcome this challenge, empirical diagnostic criteria need to be identified and validated. To achieve this goal, better understanding of nociceptive circuitry in the brain is required, preferably on a spatiotemporal scale that reflects neuronal activity at the synaptic, millisecond electrophysiological level.

DIAGNOSTIC CRITERIA FOR CLINICALLY ESTABLISHED TN: NEW CLASSIFICATION AND DIAGNOSTIC GRADING SYSTEM FOR TN

Previous diagnostic criteria of TN didn’t account for phenotypic variants and underlying etiologies1,2. With these shortcomings, this article discusses a novel diagnostic classification of idiopathic, classical, and secondary TN.3

The chief and leading complaint is typically a unilateral orofacial pain within the anatomical distribution of trigeminal nerve. Pain is often paroxysmal in nature and should not extend to posterior areas of the scalp, back of the ear, or mandibular angle, as these territories are innervated by cervical nerves4,5. Very few patients may acquire bilateral orofacial pain over the course of the disease (such in multiple sclerosis - MS), but bilateral pattern is rarely a presenting sign6. Pain induced by trigger stimuli or mechanical maneuvers was reported in 99% of patients with TN7-10. Thus, induced pain qualifies as a major criterion with a very high diagnostic value for TN. There is a minor resemblance here to allodynic pain encountered in neuropathy, but, unlike allodynia, a refractory period of several seconds or minutes by which a second pain paroxysm cannot be elicited, is another distinctive feature of TN11,12.

Spatiotemporal coding in the brain: Promise of objective orofacial pain diagnosis.Carl Saab1, MS, Ph.D, Samah Abdul Baki2, MD

AbstractPain in its mild, acute form is an adaptive alarm, whereas chronic pain is maladaptive and a curse. In particular,

chronic, neuropathic oral pain can be debilitating. Lack of objective diagnostic criteria further frustrates the patient and the caregiver, while undermining disease management. We propose that pain is mediated by specific brain activity patterns that present ‘biosignatures’ or diagnostic markers for pain. We discuss emergent brain activity convolved into rhythmic ‘oscillations’ in the context of information. Elucidating basic science mechanisms will lead to objective pain diagnosis and, consequently, better treatments for orofacial and other types of pain.

1. Associate Professor (Research), Departments of Neurrosurgery and Neuroscience, Brown University, and Rhode Island Hospital/The Warren Alpert Medical School, Providence, Rhode Island, USA.2. Chief Executive Officer and Chief Medical Officer, Bio-Signal Group - BSG, USA, and Assistant Clinical Professor, Department of Emergency Medicine and Critical Care, State University of New York - SUNY, Downstate Medical Center, Brooklyn, New York, USA.

Neuroscience



science views regarding the electrophysiology of neurons within the thalamocortical network and the causal relation of neuronal activity in this network to nociceptive behaviors23.

TECHNOLOGICAL BREAKTHROUGHS Analytical investigation of the LFP in the frequency

domain uses mostly the Fourier transform algorithm, an algorithm that decomposes a function of time (in this case the LFP) into its constituent frequency components over contiguous bandwidth (for example theta and alpha bands in the 4-8 Hz and 8-12 Hz, respectively). Hence, one can study power amplitude, as well as signal coherence to elucidate rhythmic oscillations in brain regions and ‘phase-locking’ between brain regions. We can also study the relation between action potential discharge in single-units and the LFP (for example thalamocortical spike-field coherence). To be able to record from multiple brain regions in a pre-clinical longitudinal study, light-weight, chronic-drive implants for extracellular electrophysiology have to be used in order to position several (up to 100) individual microwire electrodes in awake behaving animals28. Similar approaches in basic science have led to breakthroughs in the field of motor disorders, notably in a study of colleagues at Brown University (at Providence, Rhode Island, USA) in which they successfully decoded neocortical activity in motor cortex and concluded that such information can be used to restore virtual movement to paralyzed patients using brain-machine interface neurotechnology29. In addition, the ability to modulate neuronal activity with high specificity (for example optogenetic) is critical to further probe the causal neuronal circuitry mediating pain (not to be confused with the general, perhaps different concept of pain neuromatrix) which could potentially lead to novel therapies for severe neurologic diseases30.

CONCLUSION AND FUTURE DIRECTIONS

A fundamental weakness in the field of pain, including orofacial pain and TN, is due to a failure in identifying objective biomarkers that can be used as reliable diagnostics. We propose that the relation of micro-level interactions to the rich macro-level network

activity and behavior in real-time and in awake animals could close these critical knowledge gaps. Presently, however, we don’t have a complete appreciation of how small-scale interactions (spike activity) translate into large-scale patterns (cortical synchrony and behavior) and how these variables in turn shape and feedback into small groups. The brain’s computational power depends on how individual processing elements are networked together. Multi-scale systems are organized as complex networks that are mutually interdependent, whereby the coordinated actions of networks is responsible for global functional properties of individual neurons. Together, these concepts form elements of the nascent field of connectomics, a comprehensive description of how neurons and brain regions are functionally interconnected31. It parallels the field of systems biology that is based on the application of mathematical and computational models to specific areas of biology (e.g. genomics).

Successful approaches will require regional and international consortia of experts with diverse backgrounds ranging from computation neuroscience to engineering, working synergistically to build new technologies and infrastructures for data collection and analysis. Such concerted efforts will lead to new insights and tools for formulating testable hypotheses regarding network dynamics giving rise to orofacial pain and TN.

Ultimately, while we argue for an empirical measurement of pain, we do not promote overriding the patient’s verbal report, but merely propose adjunct, objective diagnostic tools, be it electrophysiologic or imaging, to aid healthcare providers in objectively assessing the level, quality and temporal progression of pain.

REFERENCES1. Alivisatos AP, Chun M, Church GM, et al. The brain activity map. Science. 2013 Mar 15;339(6125):1284-1285.2. Treede RD, Jensen TS, Campbell JN, et al.Neuropathic pain: redefinition and a grading system for clinical and research purposes. Neurology 2008 Apr 29;70(18):1630-1635.3. Headache Classification Committee of the International Headache Society (IHS). The International Classification of Headache Disorders-ICHD, 3rd edition (beta version). Cephalgia 2013 Jul ; 33:629-808.

therapeutic interventions27. It would be interesting to know whether these results can be replicated in a pre-clinical model of TN.

TEMPORAL CODING IN THE BRAINWe simply challenge the conventional textbook

teaching of pain as a static ‘wiring diagram’ of neurons passively encoding noxious stimuli, and argue instead in favor of an active ‘traffic pattern’ of interactions between brain regions (i.e. connectomics). Scientists and clinicians realized that pain and nociception are not equivalent and we now know that

pain is likely the result of state-dependent properties of neuronal ensembles emerging from single-unit activity. Multi-unit activity is convolved into rhythmic oscillations, tuned by thalamic feedforward input and bound together in multiple brain regions mediating pain experience. Moving from ‘rate coding’ in single-units to ‘temporal coding’ in neuronal ensembles, requires the development of new analytical and technical tools to record simultaneously from multiple units in different brain regions in awake, unrestrained animal and human subjects. This will allow us to identify a neural signature of pain while addressing long-held

Fig. 1. Diagram illustrating the process or ‘flow chart’ for diagnosing trigeminal neuralgia (Cruccu et al., 2016 / reference number 4).

4746

INTRODUCTION Nowadays, science and dental materials develop

faster than ever. Newer materials and concepts are addressed constantly to dental community. Indeed, it is a difficult task for practitioners to keep the hectic pace. It is a common knowledge that the varieties describing an in vitro experiment for materials’ testing (such as kind of chewing simulator, food medium or lack of it,

choice of antagonists, length of sliding path, loads and many more), are very diverse and the modulation of only one of them can completely change the outcomes. Therefore, our purpose was to create a reliable and feasible method for in vitro testing of dental materials, which will recreate the chewing process as closely as possible. Using recently developed chewing simulator “Sofia1, we compared the wear resistance of some new and old composite resins in order to help dentists gaining better insight into this complicated and often confusing issue.

In vitro wear resistance of five composite restorative materials: A comparative research study.Ivan Chakalov1, DDS, PhD, Pavlina Ivanova2, DMD

AbstractIntroduction: Wear resistance of restorative materials is among the main properties that determine stability and

long-term success of dental restorations. Most reliable data regarding wear resistance is obtained via clinical research, however, latter is expensive and time consuming. This is why many in vitro chewing simulators were developed to enable researchers obtaining, within short time, relevant data regarding wear resistance of tested materials.

Objective of the study: To develop a method for in vitro wear testing in order to compare wear resistance of five composite restorative materials. Tested materials were deliberately selected with five to ten years difference of launching on the market as representatives of different concepts of scientific development.

Materials and Methods: For the purpose of the present study, an in vitro wear testing device - the chewing simulator "Sofia", was developed, based on a thorough analysis of movement trajectory and force profile during chewing. The analysis indicated pattern of occlusal interaction in agreement with the functional occlusal concept. A chewing simulator was designed and constructed in order to mimic force profile and sliding length established in in vivo research during physiological chewing. Specimens were fabricated out of the selected composite materials and subjected to in vitro chewing simulation tests. All materials were tested in a three-body wear test using an artificial food bolus formula described by previous researchers. One of the materials was tested also in a distilled water medium in order to compare the data with other two-body chewing simulator’s results. Measurements were performed using contact profilometer (1μm precision) following a predetermined mesh.

Results: Our results indicated no relationship between wear and year of production. The most wear resistant composite was the nanohybrid, while the second most resistant to wear was a mid-filler - the oldest among tested materials. Analysis indicated a very low coefficient of variation of results compared to other chewing simulators.

Conclusion: The present study indicated that newer materials and developments do not necessarily lead to a better wear resistance of composite materials. The most wear resistant among tested materials was the tested nanohybrid composite.

1. Assistant Professor, Department of Prosthetic Dentistry, Faculty of Dental Medicine, Medical University of Sofia, Sofia, Bulgaria2. Restorative Dentist in private practice, Sofia, Bulgaria

Dental Research

4. Cruccu G, Finnerup NB, Jensen TS,et al. Trigeminal neuralgia New classification and diagnostic grading for practice and research. Neurology 2016 Jul 12;87(2):220-228.

5. Gronseth G, Cruccu G, Alksne J, et al. Practice Parameter: The diagnostic evaluation and treatment of trigeminal neuralgia (an evidence-based review). Report of the Quality Standards Subcommittee of the American Academy of Neurology and the European Federation of Neurological Societies. Neurology 2008 Oct 7;71(15):1183-1190.6. Melzack R, Terrence C, Fromm G, Amsel R. Trigeminal neuralgia and atypical facial pain: use of the McGill Pain Questionnaire for discrimination and diagnosis. Pain 1986 Dec 1;27(3):297-302.7. Rushton JG, Olafson RA. Trigeminal neuralgia associated with multiple sclerosis: report of 35 cases. Arch Neurol 1965 Oct;13(4):383-386.8. Maarbjerg S, Gozalov A, Olesen J, Bendtsen L. Trigeminal neuralgia–a prospective systematic study of clinical characteristics in 158 patients. Headache 2014 Nov-Dec;54(10):1574-1582.9. Nurmikko TJ. Altered cutaneous sensation in trigeminal neuralgia. Arch Neurol 1991 May ;48(5):523-527.10. de Siqueira SRDT, Nóbrega JCMN, Valle LBS, et al. Idiopathic trigeminal neuralgia: clinical aspects and dental procedures. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004 Sep 30; 98(3):311-315.11. Karol EA , Karol MN . A multiarray electrode mapping method for percutaneous thermocoagulation as treatment of trigeminal neuralgia. Technical note on a series of 178 consecutive procedures. Surg Neurol 2009; 71(1):11-17.12. Calvin WH, Devor M, Howe JF. Can neuralgias arise from minor demyelination? Spontaneous firing, mechanosensitivity, and after discharge from conducting axons. Exp Neurol 1982 Mar 31;75(3):755-763. 13. Devor M, Amir R, Rappaport ZH. Pathophysiology of trigeminal neuralgia: the ignition hypothesis. Clin J Pain 2002 Jan-Feb;18(1):4-13.14. Alshukry A, Salburgo F, Jaloux L, Lavieille JP, Montava M. Trigeminal neuralgia (TN) : A descriptive literature analysis on the diagnosis and management modalities . J Stomatol Oral Maxillofac Surg 2017 Jun 23; Epub ahead of print15. Cruccu G, Gronseth G, Alksne J , et al. AAN‐EFNS guidelines on trigeminal neuralgia management. Eur J Neurol 2008;15(10):1013-1028. 16.Dubner R,Sharav Y,Gracely RH,Price DD . Idiopathic trigeminal neuralgia: sensory features and pain mechanisms. Pain 1987 Oct;31(1):23-33.17. Zakrzewska JM, Jassim S, Bulman JS. A prospective, longitudinal study on patients with trigeminal neuralgia who underwent radiofrequency thermocoagulation of the Gasserian ganglion. Pain 1999 ;79(1):51-58.18. O’Connor AB, Schwid SR, Herrmann DN, Markman JD, Dworkin RH. Pain associated with multiple sclerosis: systematic review and proposed classification. Pain 2008;137(1):96-111.

19. Truini A, Barbanti P, Pozzilli C, Cruccu G. A mechanism-based classification of pain in multiple sclerosis. J Neurol 2013;260(2):351-367.20. Saab CY . Chronic pain and brain abnormalities. Elsevier Science Publishing Co Inc,USA,2013.21. Melzack R. From the gate to the neuromatrix. Pain 1999 Aug; Suppl 6 : S121-126.22. Melzack R. Pain and the neuromatrix in the brain. J Dental Edu 2001 ;65(12):1378-1382.23. Saab CY. Pain-related changes in the brain: diagnostic and therapeutic potentials. Trends Neurosc 2012 ; 35(10):629-637.24. Buzsáki G, Anastassiou CA, Koch C. The origin of extracellular fields and currents--EEG, ECoG, LFP and spikes. Nat Rev Neurosci 2012 May 18 ;13(6):407-420.25. Sarnthein J, Stern J, Aufenberg C, Rousson V, Jeanmonod D. Increased EEG power and slowed dominant frequency in patients with neurogenic pain. Brain 2005;129(1):55-64.26. Stern J, Jeanmonod D, Sarnthein J. Persistent EEG overactivation in the cortical pain matrix of neurogenic pain patients. Neuroimage 2006 Jun ;31(2):721-731.27. LeBlanc BW, Bowary PM, Chao YC, Lii TR, Saab CY. Electroencephalographic signatures of pain and analgesia in rats. Pain 2016 Oct ;157(10):2330-2340.28. Voigts J, Siegle JH, Pritchett DL, Moore CI. The flexDrive: an ultra-light implant for optical control and highly parallel chronic recording of neuronal ensembles in freely moving mice. Front Syst Neurosci 2013 May 13 ;7:8.29. Hochberg LR, Bacher D, Jarosiewicz B, et al. Reach and grasp by people with tetraplegia using a neurally controlled robotic arm. Nature 2012 May 16;485(7398):372-375.30. LeBlanc BW, Cross B, Smith KA, et al. Thalamic Bursts Down-regulate Cortical Theta and Nociceptive Behavior. Sci Rep 2017 May 30;7:2482.31. Sporns O. Discovering the Human Connectome. Reprint edition. The MIT Press; February 12, 2016.

Recommended Reading List-Apkarian, AV, Baliki MN, Geha PY. Towards a theory of chronic pain. Prog Neurobiol 2009; 87(2): 81-97.-Martucci KT, Ng P, Mackey S. Neuroimaging chronic pain: what have we learned and where are we going? Future Neurol 2014 Nov; 9(6): 615-626.-Saab CY. Chronic Pain and Brain Abnormalities. 2013, 1st Edition - London, Boston; Elsevier Academic Press.-Rosa MJ, Seymour B. Decoding the matrix: benefits and limitations of applying machine learning algorithms to pain neuroimaging. Pain 2014; 155(5): 864-867.

Corresponding author:Carl [email protected]




Fig. 4. The rotating shaft (21) transmitting motion to the antagonist, has a cam block (18) and an eccentric (19) attached to it.

MATERIALS AND METHODS The Chewing Simulator "Sofia"

For the purpose of the present study, a chewing simulator, “Sofia”, was designed and constructed. After thorough analysis of different parameters of physiological chewing, we decided to have a basis for the principle of the simulator upon "the functional occlusal concept" of Le Gall and Lauret2: this concept is based on the observation that human chewing is oriented in a centripetal direction (from outside towards center), while the movement utilized in traditional occlusal adjustments are centrifugal (from center towards outside). Since different sets of masticatory muscles are responsible for these movements, a subsequent difference in the registered tooth contacts is present. In fig. 1, the cyclogram on the left represents an experimental cycle carried out according to functional occlusion concept (A); the cyclogram to the right represents an experimental cycle based on the loading profile according to the conventional gnathological concept (B). The “Sofia” chewing simulator is capable of reproducing both loading profiles, but for the purpose of the present study, we decided to use the first one (A) because it reflects the characteristics during centripetal movement, which represents more accurately the inward orientation of the chewing cycle.

Figures 2, 3, 4 provide a more schematic view of the main components of the machine. A characteristic part of the construction is the use of a permanent Nd (Neodymium) magnet and a magnetic cam which generates a variable load, reproducing the change of load during the different stages of the chewing cycle. The ascending motion of the antagonist is created by an alleviating cam. The length of the track is determined by an interchangeable eccentric.

The antagonist trajectory during one chewing cycle consists in four phases (Fig. 5):

1- descending of the antagonist towards the specimen (this movement reproduces the initial contact between buccal cusps of antagonist teeth during chewing cycle)

2- sliding motion between antagonist and the specimen under predetermined variable load (this corresponds to the sliding motion from the point of initial contact to the position of central occlusion which is accompanied by an increase

in load until it reaches its maximum value; the subsequent sliding movement during the cycle is carried out under load, lower than the maximum)

3- separation of the antagonist from the specimen (it reproduces the end of occlusal phase of chewing cycle)

4- return of the system in a starting position (preparation of the dentition for a new occlusal phase)

Most important parameters of the wear simulator:- Length of the track: 0 - 7mm- Maximum distance between the antagonist and the

specimen: 2mm- Load: 0-70 N- Frequency: 0.1-2 Hz - Number of specimens tested simultaneously: 4

Composite materials For the aim of the recent experiment, we decided to

chose five composite materials with five to ten years difference of launching on the market: Herculite HRV*, Heliomolar**, Charisma***, Filtek™ Silorane****,

* Herculite® HRV™ Microhybrid Dental Composite (Kerr Dental).** Heliomolar® Dental Hybrid Composite (Ivoclar Vivadent).*** Charisma® (Heraeus Kulzer) Hybrid Composite.**** Filtek™ Silorane (3M ESPE) Low Shrink restorative and methacrylate composite.***** 3M™ ESPE™ Filtek™ Ultimate Universal Restorative System

OBJECTIVE OF THE STUDYThe purpose of the present study was to create

a reliable method for in vitro wear testing that will reproduce as closely as possible various parameters characterizing physiological chewing process. The objective was to use the method in order to compare several composite restorative materials belonging to different decades of market launching and generation of development, in an attempt to present an answer

to whether newer materials are superior to older generations of materials, in terms of wear resistance.

Working hypothesis Newer dental materials incorporate latest scientific

developments and breakthroughs. Therefore, they are expected to have an improved wear resistance when compared to older generations of materials.

Fig. 1. The cyclogram represents one experimental chewing cycle reproduced by the chewing simulator. Horizontal line (the x-axis) of the two diagrams represents the time of one experimental cycle. The diagram in red shows the change of force over time, while the blue one measures the distance between the antagonist and the tested specimen. When the blue line coincides with the x-axis on the upper diagram the antagonist in is contact with the specimen. Only during this interval the loading force changes. In the second part of the experimental cycle, the antagonist and the specimen are separated - this corresponds to the part of the chewing cycle when teeth are out of contact.

Fig. 2. Schematic view of the main components of the chewing simulator "Sofia":1. the base on which the chariot is mounted (2)3. electric gear motor4. the rocker arm module

N.B. The "Sofia" simulator was developed at Sofia Faculty of Dental Medicine as part of a Ph.D. work.

Fig. 3. Rocker arm21- stand24- holder of the antagonist (pearl, d=4mm)25- holder of the magnetic block26- constant load.

A B


Statistical methodsData were recorded and processed using the statistical

software IBM SPSS Statistics 19.0.0.P < 0,05 was set as the significance level at which

the zero hypothesis would be rejected. The following methods were applied:

1. Descriptive analysis 2. Analysis of variance 3. Nonparametric Kolmogorov-Smirnov test and

Shapiro-Wilk test 4. Nonparametric Kruskal-Wallis test 5. Nonparametric Mann-Whitney test6. T-test (Student's t-distribution).

RESULTS Results are displayed in table 2. The resultant

arrangement of materials tested in artificial food medium from highest to lowest wear resistant was the following:

Filtek Ultimate> Herculite> Heliomolar > Charisma > Filtek Silorane

Under the conditions of the present study, the most wear resistant material was the nanohybrid Filtek Ultimate: the average wear debth for that material was 47μm. The second most wear resistant material was the Herculite with an average 87 μm. The least wear resistant materials were Charisma and Filtek Silorane with 133-135 μm with no statistically significant difference between them.

MaterialYear Kind

Organical matrix Fillers

Kind Size (µm) Weight %HERCULITE HRV1980

Minifilled Microhybrid

Bis-GMATEGDMA

Barium silicate0,6 79

HELIOMOLAR1986

Microfilled Bis-GMAUDMADecandiol dimethacrylate

SiO2YbF3Prepolymers

O,040,2 66.7

CHARISMA1991

Minifilled microhybrid

Bis-GMATEGDMA SiO2

0,7–20,01–0,07 78

FILTEKSILORANE2007

Microhybrid Silorane resin Quartz

Yttrium fluorite76

FILTEK ULTIMATE2010

Nanohybrid Bis-GMAUDMATEGDMAPEGDMABis-EMA

SiO2

Zirconia

20 nm

4–11nm78,5

Material Number of experiments X SD V

Herculite 379 67,55a 24,63 36,46Heliomolar 105 87,27c 39,52 45,29Charisma 214 132,85d 40,34 30,36

Filtek Silorane 200 135,24d 70,25 51,95Filtek Ultimate 213 47,19e 21,16 44,84

Table 1. Description of the five selected composite materials.

Table 2. Comparative analysis of average wear debths of the tested materials* same letter after results indicate no significant difference, different letters indicate significant difference (p<0,05); X mean value; SD- standard deviation; V- coefficient of variations.

and Filtek Ultimate***** (Table 1). On each sample, 5-6 experiments with 50,000 chewing cycles were conducted. Some samples were tested in artificial food medium and others, in distilled water. The applied force profile varied in different parts of the traces in agreement to the one established for the physiological chewing in vivo; therefore the depth of the traces was unequal.

Specimen fabrication 39 specimens were fabricated from five different

composite materials. For this purpose, metal rings with an outer diameter of 25mm, inner diameter 24mm, and 8mm height were utilized. Metal rings were placed in a specially designed holder, which was firmly fixed onto a glass slab with a smooth surface. Preliminary rugosimetric measurement revealed that obtained surface corresponded to a 1,500-2,000 grit glass paper polishing. 2-2.5 grams of tested material were applied into the ring and carefully pressed against the glass slab until a uniform layer of about 1-2 mm was achieved. Polymerization of the material was carried out with a 2,000 mW/cm2 (milliWatt per square centimeter) light-curing lamp in 9 areas for each sample. Each area was polymerized separately using two polymerization modes – first with the “soft start” mode for 20 seconds (starting with low light intensity and gradually increasing the intensity towards the end of the curing cycle) and then with the "pulse" mode (sequence of maximum intensity light impulses and periods of lack of light irradiation). Subsequently, the remaining volume of the sample was filled up with pink cold-curing (self-curing) resin (Duracryl™, Spofa Dental). Samples containing air voids coinciding at the place of the tests were eliminated.

Artificial food mediumHerculite® specimens were divided in two groups -

the first group was tested in distilled water and the second, in artificial food medium. The artificial food medium was prepared according to Leinfelder’formula3. All other composite samples were tested only in artificial food medium.

AntagonistsPrefabricated silicon nitride spheres with a diameter

of 4 mm were used for the tests. Spheres were mounted

on a special holder. Standardization in shape, hardness, and roughness of their surface was beneficial in order to reduce variations in test results.

Measurement methodMeasurement was performed using a contact

profilometer (with a vertical accuracy of 1µm and horizontal accuracy of 5 µm), following a predetermined mesh (Fig. 6). For each wear groove, a number of 30 measurements were performed.

Fig. 5. The antagonist trajectory during one chewing cycle

Fig. 6. Shematic representation of the measuring steps following the predetermined mesh.

5352

INTRODUCTIONRadiographic imaging of alveolar peri-implant bone

is an important diagnostic tool in implant dentistry. Intraoral peri-apical radiography is commonly used for the follow-up examination of dental implants, with the aim of assessing marginal bone level and detecting signs of implant’s osseointegration failure1. One of the main disadvantages of conventional radiography (CR) is its inherent 2D nature, with anatomical superposition and geometric distortion, which will lead to visibility limitations of, for example, intra-osseous defects and their changes over time2. CR demonstrates mesial and distal aspects of alveolar bone/fixture interface and marginal alveolar bone tangential to the X-ray beam. However, initial post-insertion bone loss occurs mostly on buccal aspect of dental implants, since bone is often thin on this aspect3.

Due to anatomical superposition and projection methods in CR, limited information is provided on

peri-implant buccal and lingual defects. Therefore, there is a need to develop an effective radiographic method for postoperative evaluation of peri-implant bone quality and density.

Over the past few years, CBCT has become an increasingly important diagnostic tool in dentistry, providing three-dimensional (3D) radiographic information of teeth and jaws. As a result, CBCT is now widely used for diagnosis and treatment planning, especially in implant dentistry4.

Buccal and lingual lesions of peri-implant bone can be evaluated by CBCT, but there has been some concern expressed about the validity of the displayed data due to artifacts induced by titanium implants surfaces which tend to produce a low-density halo around implant contour, leading to misdiagnosis and false interpretation (Fig. 1).

This article addresses the most common type of artifact induced by dental osseous titanium implants (mainly beam hardening), its effect on the quality of displayed image, and methods used to reduce such artifact, with the ultimate goal of concluding whether or not CBCT can be used as a postoperative diagnostic imaging technique for the evaluation of osseointegration of dental endosseous implants.

Peri-implant bone radiolucencies: Reality or illusion?

Sara Kassem Moussa1, BDS, DU CBCT, DESS Oral Biol., DESS Oral Maxillofac. Radiol. Saydé Sokhn2, BDS, DESS Oral Biol., DESS Oral Maxillofac. Radiol.Ibrahim Nasseh3, Dr. Chir. Dent., DSO, FICD, FITI

AbstractDental endosseous, titanium, osseointegratable implants has become a common and popular method for replacing

missing teeth. Post-operative assessment of endosseous dental implants (fixtures) mainly depends on monitoring mobility, pain, infection, inflammation, and marginal alveolar peri-implant bone loss. Radiological follow-up is one of the most important methods for evaluating bone condition around endosseous implants (mainly periapical and panoramic radiographs), but its limitations (anatomical superposition, geometric distortion) led to an increase in the use of Cone Beam Computed Tomography (CBCT) imaging as a method for 3D evaluation of implant sites. Artifacts created by CBCT (mainly beam hardening) limit the visibility of peri-implant bone around dental endosseous implants and misdiagnose the true gray values.

The aim of this article is to show the possible efficiency of CBCT in assessing osseointegration of endosseous dental implants.

1. Clinical Instructor2. Chief of Clinical Services3. Professor, 1,2,3. Division of Dentomaxillofacial Radiology and Imaging, Department of Oral Medicine and Maxillofacial Radiology,Faculty of Dental Medicine, Lebanese University, Beirut, Lebanon

Oral and Maxillofacial Radiology and Imaging

Contrary to what was expected, more recent materials did not necessarily perform better, compared to older ones. The most wear resistant material - Filtek Ultimate, was also the most recently launched on the market. However, the second most resistant was the Herculite - material that has been on the market for more than 30 years. The second most recent material - Filtek Silorane, was the least wear resistant among tested materials. The resultant arrangement of materials was similar to those established by other studies.

DISCUSSION In the present study, we compared between five

well known composite materials with five to ten years difference of launching on the market - Herculite HRV, Heliomolar, Charisma, Filtek Silorane, and Filtek Ultimate. The materials belong to different types of composites - nanofilled, mid-filled and mini-filled, according to Bayne’s classification (Bayne et al., 1994). Filtek Silorane showed the lowest wear resistance which was unexpected because according to manufacturer’s instructions, this material is indicated for large class 1 and 2 restorations4,5, and, in addition to that, it is the second most recently launched on the market (2007). As reported by Mine and co-workers6, Filtek Silorane has lower volume percentage of filler (76%) compared to other microhybrid composites (Clearfil AP-X and Filtek Z100).

Heliomolar is micro-filled composite launched in 1986: its particles are approximately 0,04 µm in diameter. In order to surround and bond the filler particles together, more organic matrix is needed. Therefore, the micro-filled composites have lower volume percentage of filler, poorer mechanical properties, greater polymerization shrinkage, and water sorbtion.

The other tested material - Charisma, showed greater wear than Heliomolar and Herculite HRV. Same results were reported by other authors7.

CONCLUSIONIt was useful to compare our outcomes to those of

other authors who preferred different in vitro methods for evaluation of wear resistance. In the literature there are controversial data regarding different in vitro and in vivo researches. Dynamic force, the unique loading profile and the functional occlusal concept on which the chewing simulator “Sofia” is based, created

different experimental conditions. Most importantly, wear resistance arrangement following our method corresponded to results obtained by other researchers.

According to our (present) study, newer materials and developments do not necessarily lead to a better composite wear resistance8, and under the research conditions of our (present) study, the most wear resistant, among the five tested composites, was the tested nanohybrid composite - Filtek Ultimate9.

Conflict of Interest Disclosure StatementThe authors affirm that they have no financial

affliliation (employment, honoraria, direct payment, stock ownership, consultantships, patent licensing arrangements) or involvement with any commercial organization or corporation, with any direct financial or economic interest in the subject or materials discussed in this manuscript. Any other potential conflict of interest is disclosed.

REFERENCES1. Chakalov IE. Wear resistance of dental materials. In vitro studies.Ph.D thesis, 2014; Sofia, Bulgaria. 2. Lauret JF, Le Gall MG. The function of mastication: a key determinant of dental occlusion. Pract Periodontics and Aesthet Dent 1996 Oct;8(8):807-817.3. Leinfelder KF, Suzuki S. In vitro wear device for determining posterior composite wear. J Am Dent Assoc 1999 Sep;130(9):1347-1353.4.Multimedia.3m.com/mws/media/5092050/Filtek-silorane-brochure-australia.pdf.5.Multimedia.3m.com/mws/media/5980610/Filtek-silorane-tpp-ebu.pdf.6. Mine A, De Munck J, Van Ende A et al. TEM characteriazation of a silorane composite bonded to enamel/dentin.Dent Mater 2010 Jun;26(6):524-532.7. Kawai K, Leinfelder K. In vitro evaluation of OCA wear resistance of posterior composites. Dent Mater 1995 July;11(4):246-251.8. Chakalov I, Ivanova P, Apostolov N. Influence of different tribological mechanisms on in vitro wear stimulation results of composites. MedInform 2014; Issue 1:28-34. DOI: 10.18044/MedInform.201411.28.9.Multimedia.3m.com/mws/media/6299430/Filtek-ultimate-technical-product-profile-cee.pdf.

Corresponding author:Ivan [email protected]




words, the sensor records too much energy because only the higher-energy X-rays penetrate the implant, whereas the lower energetic (lower wavelength) rays of the polychromatic spectrum emitted by the X-ray source will suffer substantial absorption when passing through dense objects. Hence, recorded intensity will be too high (i.e., the gray value too dark) in relation to other less hardening structures4,5.

Beam-hardening artifact in dental endosseous implants will appear as dark band or halo around an implant or as an erroneous dark hourglass-like shape in between implants. This artifact will change visibility and accuracy of surrounding bone peri-implant inter-phase, leading to inaccurate assessment of peri-implant space (Fig. 3).

An increase in beam-hardening effect is noticed when the X-ray path length increases and in cases where the X-ray passes through two or more metallic objects (Fig. 4)7.

The finding of artifacts, mostly on buccal and lingual surfaces compared with occlusal surface, indicates that artifacts appear in horizontal direction, not vertical, on 3D surface models (Fig.5). The difference is likely attributable to the direction of the X-ray beam, because the emitter of a CBCT scanner rotates around an object in horizontal direction8. Artifacts were also observed to be frequently found in axial radiographic images9.

Due to artifacts in images displayed by CBCT, it is important to realize whether radiolucent regions viewed around dental endosseous implants (buccal, lingual, and in-between) are reality or illusion, as a result of beam-hardening artifact.

LITERATURE REVIEWMany authors1,3,4,9 discussed limitations of CBCT

machines in evaluating bone around and in between dental endosseous implants due to beam hardening effect, resulting in darkening of areas adjacent to implants and even complete loss of gray values between adjacent metallic objects, leading to false diagnosis.

Such results were showed by Benic and associates1

who reached a conclusion that regardless of dental implant position, artifacts were always present in proximity of dental titanium endosseous implants, with an increased gray value at buccal and lingual aspects of all implant sites, whereas long axis of mandibular body

was the region with reduced gray values1. Ritter and co-workers2 evaluated the diagnostic

accuracy for assessing peri-implant osseointegration using CBCT: they concluded that CBCT efficiency is limited in accurately determining buccal bone levels of dental osseous implants in vertical as well as horizontal dimensions2. Schulze and associates4 showed (based on mathematical assumption and explanation) that the missing data problem due to beam hardening is most prominent in the shadow between two implants. Consequently, these regions have to be diagnosed under the assumption that these peri-implant radiolucencies do not necessarily implicate a loss of peri-implant bone.

A study conducted by Shiratori and co-workers9 proved that CBCT can be considered as a precise method for measuring buccal bone volume around dental implants; CBCT was precise in determining bone height between implant platform and first contact with bone at buccal wall. Authors mentioned that artifacts observed in the study did not interfere with the measurements, as implant dimensions were retained in the CBCT, probably due to the software filters for images formatting and type of the tomography capture protocol9.

Metal artifact reduction methodsUnderstanding image formation principles and

being familiar with the nature of artifacts and their characteristic appearances in CBCT images are very important to avoid confusion with normal anatomy or post-surgical variations. It is presently unknown whether these artifacts can be reduced by using different CBCT scan techniques or settings10.

Metal artifact reduction can be carried out by11: 1- Adapted scanning technique2- Specific reconstruction algorithm (pre-processing

technique)3- Post-processing technique.

1- Adapted scanning technique:Field of view (FOV), kilovoltage peak (kVp),

milliamperage (mA), and voxel size are the effective parameters in decreasing or increasing metal artifacts during scanning procedure11-12.

Selection of FOV and voxel size can be detrimental in diagnosing dental peri-implant defects. It is possible

BEAM HARDENINGThe choice of an accurate and reliable imaging

modality in the assessment of peri-implant marginal alveolar bone status is clinically important in terms of postoperative monitoring of stability and selection of appropriate treatment3.

CBCT has the ability to provide cross-sectional images with lower radiation doses, compared to conventional multi-slice computed tomography (MSCT); this fact broadened diagnostic possibilities of CBCT in dentistry. CBCT provides accurate linear measurements of dentomaxillofacial structures; however, this imaging modality is prone to the appearance of artifacts generated by dental endosseous implants1.

An image artifact is a visualized structure in the reconstructed data that is not present in the object under investigation5. Artifacts can seriously affect the quality of CBCT images by decreasing the contrast between adjacent objects and ultimately lead to inaccurate or false diagnosis6.

Among different kinds of artifacts (such as scatter, noise artifacts, and others), beam-hardening artifacts were identified to be the most prominent artifacts induced by dental implants4,5. By definition, beam hardening is the process by which low energy photons in a polychromatic beam are attenuated after passing through metallic objects such as dental endosseous implants, leading to an increase in beam average energy level, i.e. the beam becomes harder (Fig. 2). In other

Fig. 1. Cross-sectional images of four different implant cases (a, b, c and d) depicting low-density halo/area around implant’s contour.

Fig.2: Schematic drawing explaining beam hardening phenomena in dental endosseous implants. (a) Polychromatic x-ray beam. (b) Attenuation of low energy x-rays. (c) Increase in beam average energy level. (d) Increase in the intensity recorded will be displayed as low-density areas around the implant.

(a) (b) (c) (d)


to obtain smaller voxel sizes with smaller FOVs, leading to improvement in spatial resolution of high-contrast structures; This superior spatial resolution, which is the ability to discriminate objects of different attenuation separated by very small distances, is one of the most attractive qualities of CBCT3. It is true that with decrease in voxel size, a better spatial resolution image will be obtained but it is important to mention that the smaller the voxel size, the greater the noise13.

Razavi and associates14 and Kamburoğlu and co-workers3 discussed the effect of voxel size in determining the accuracy of measuring cortical bone thickness adjacent to dental endosseous implants; It was concluded, in both papers, that machines with voxel size of 0.3mm and more may not produce sufficient resolution of the thin cortical bone, leading to inaccurate reading, whereas machines with voxel size of less than 0.3mm will produce better resolution and more accurate measurements of the thin bone, especially when the thickness of cortical bone increases above 0.8mm3,14.

A more pronounced beam hardening effect was observed in machines working at 80 kV and less artifact in machines with higher kV range (120-140 kV)4,11.

A study conducted by Chindasombatjaroen and associates15 demonstrated that higher tube voltage was associated with smaller artifacts; This is because increasing the tube voltage increases the effective X-ray energy, which can improve beam penetration and thus, reduce the missing projection data, and in turn, reduce artifact areas15. Similarly, a study conducted by Esmaeili and co-workers16 showed that scanning under high kV conditions reduces the amount of artifacts.

The only significant difference between these protocols is the milliamperage (mA); In most cases, mA varied between protocols because of the difference in the number of acquired projections (e.g. the more the projections, the bigger exposure time is). Although it can be expected that a larger number of projections leads to artifact reduction, there was no perceptible difference between high-mAs and low-mAs11. This means that increasing in mA will only lead to minor improvements in image quality.

Artifact reduction (based on adjustment of exposure parameters) is limited when comparing the minimal

reduction gained with respect to image quality in relation to increase in radiation dose, so the devices need to be optimized by enabling exposure factors that are appropriate for artifact reduction and finding a balance with radiation dose11.

2- Specific reconstruction algorithms (pre-processing technique)

Several metal artifact reducing methods for the CBCT system have been proposed during the past few years, most of which need to pre-reconstruct FOV and segment metal areas in the 3D space17.

In pre-processing algorithm, the metal part in the basis projection is located, and then, using the interpolation algorithm, metal projection data are modified. From these pre-processed raw data, images are reconstructed and metal section is retrieved18.

Nowadays, CBCT companies are actively developing artifact-reducing algorithms to be used during image reconstruction. These processes, although contributory, are rather slow and may cause further time consuming to the total reconstruction process. Contemporary approaches attempt to avoid reconstruction errors either by supplementing missing or incorrect information in

Fig. 5. Cross-sectional image depicting low density area around a dental endosseous implant, buccally and lingually.

Fig . 3. (a) Axial cut depicting beam hardening artifact between adjacent endosseous implants in the form of hourglass low density area. (b) The same axial cut with illustrated doted hourglass in inter-implant beam hardening region.

Fig. 4. Four different axial cuts for different patients depicting different patterns of beam hardening artifacts between adjacent endosseous implants (white arrows indicate regions of beam hardening).


6. Demirturk Kocasarac H, Helvacioglu Yigit D, Bechara B, Sinanoglu A, Noujeim M. Contrast-to-noise ratio with different settings in a CBCT machine in presence of different root-end filling materials: an in vitro study. Dentomaxillofac Radiol 2016;45(5), 20160012. doi: 10.1259/dmfr.20160012. 7. Ibraheem I. Reduction of artifacts in dental cone beam CT images to improve the three dimensional image reconstruction. J Biomed Sc Eng 2012; 5: 409-415.8. Nabha W, Hong Y-M, Cho J-H, Hwang H-S. Assessment of metal artifacts in three-dimensional dental surface models derived by cone-beam computed tomography. Korean J Orthod 2014 Sep; 44(5): 229–235.9. Shiratori LN, Marotti J, Yamanouchi J, Chilvarquer I, Contin I, Tortamano-Neto P. Measurement of buccal bone volume of dental implants by means of cone-beam computed tomography. Clin Oral Impl Res 2012; 23: 797–804.10. Helvacioglu-Yigit D, Demirturk Kocasarac H, Bechara B, Noujeim M. Evaluation and Reduction of Artifacts Generated by 4 Different Root-end Filling Materials by Using Multiple Cone-beam Computed Tomography Imaging Settings. J Endod 2016 Feb;42(2):307-314.11. Pauwels R, Stamatakis H, Bosmans H, Bogaerts R, Jacobs R, Horner K, Tsiklakis K, The SEDENTEXCT Project Consortium. Quantification of metal artifacts on cone beam computed tomography images. Clin Oral Impl Res 2013; 24 (Suppl. A100): 94–99.12. Bechara B, Alex McMahan C, Moore WS, Noujeim M, Teixeira FB, Geha H. Cone beam CT scans with and without artefact reduction in root fracture detection of endodontically treated teeth. Dentomaxillofac Radiol 2013; 42(5):20120245. doi:10.1259/dmfr.20120245. 13. Spin-Neto R, Gotfredsen E, Wenzel A. Impact of voxel size variation on CBCT-based diagnostic outcome in dentistry: a systematic review. J Digit Imaging 2013Aug;26(4):813-20. doi: 10.1007/s10278-012-9562-7. 14. Razavi T, Palmer RM, Davies J, Wilson R, Palmer PJ. Accuracy of measuring the cortical bone thickness adjacent to dental implants using cone beam computed tomography. Clin Oral Impl Res 2010; 21, 718–725.15. Chindasombatjaroen J, Kakimoto N, Murakami S, Maeda Y, Furukawa S . Quantitative analysis of metallic artifacts caused by dental metals: comparison of cone-beam and multi-detector row CT scanners. Oral Radiol 2011 Dec;27(2):114-120.16. Esmaeili F, Johari M, Haddadi P. Beam hardening artifacts by dental implants: Comparison of cone-beam and 64-slice computed tomography scanners. Dent Res J (Isfahan) 2013; 10(3): 376–381.17. Wang Q, Li L, Zhang L, Chen Z and Kang K. A novel metal artifact reducing method for cone-beam CT based on three approximately orthogonal projections. Phys Med Biol 2013 Jan 7; 58(1): 1-17. doi:10.1088/0031-9155/58/1/118. Parsa A, Ibrahim N, Hassan B, Syriopoulos K, Van der Stelt P. Assessment of metal artefact reduction around dental titanium implants in cone beam CT. Dentomaxillofacial Radiol 2014;43 (7), 20140019. doi: 10.1259/dmfr.20140019.

19. Kamburoglu K, Kolsuz E, Murat S, Eren H, Yüksel S, Paksoy CS. Assessment of buccal marginal alveolar peri-implant and periodontal defects using a cone beam CT system with and without the application of metal artefact reduction mode. Dentomaxillofac Radiol 2013 Aug;42(8): 20130176. doi: 10.1259/dmfr.20130176. 20. Sirin Y, Horasan S, Yaman D et al. Detection of crestal radiolucencies around dental implants: an in vitro experimental study. J Oral Maxillofac Surg 2012 Jul;70(7):1540-1550.

Corresponding author:Ibrahim [email protected]

projection images or by integrating some sort of meta-information into an iterative* reconstruction process19.

Because these artifacts are system-immanent to the data acquisition process, they cannot be avoided completely; Simple back-projection algorithms - such as the cone-beam algorithm of Feldkamp** (Feldkamp LA, Davis LC, Kress JW, 1984) - are not able to avoid them at all, if no additional artifact suppressing means are applied4. Most of algorithms under investigation can be categorized as projection interpolation, iterative reconstruction, and filtering algorithms, using different approaches or combinations thereof to limit the effect of metal objects in the image.

It is generally agreed that continuous increase in computational power will lead to an increasing clinical implementation of artifact reduction using iterative reconstruction algorithms. It may take several more years before iterative algorithms for CBCT are implemented in routine clinical practice11.

All these methods require massive computational power, which has so far prevented them from being used in daily routine work performed by commercial CBCT. Luckily, increasing computational speed and advances in graphics processing units can be expected to overcome this problem19.

3- Post-processing technique:This technique applies metal reduction artifact on

DICOM*** files not on raw projection data, and this means that post-processing is based on segmentation and modification of metal areas in each projection image and reconstruction of final image with modified data.

In term of artifact reduction, pre-processing of the actual physical image acquisition is superior to post-processing of affected data18.

CONCLUSIONIn 2012, an in vitro study, conducted by Sirin and

associates20, compared the diagnostic potentials and practical advantages of different imaging modalities in detecting bone defects (crestal radiolucencies) around dental implants; Authors concluded that "DDR (direct digital radiography) may provide a faster and more confident diagnostic option that is as accurate as PR (periapical radiography) in detecting peri-implant

radiolucencies" and that "CBCT has a comparable potential to these intraoral systems but with slower decision making and lower image quality, whereas panoramic radiography (PANO) and MSCT become more reliable when bone defects have a diameter that is at least 1,5mm larger than that of the implant"20.

Beam hardening affects the quality of reconstructed images. As a result, diagnosis of areas around or in between dental osseous implants by CBCT imaging technique should be avoided due to the fact that those areas show excessive loss of projectional information. Metal artifact reduction methods lead to minor improvement in image quality. In conclusion, clinicians must be careful while using CBCT imaging technique for the assessment of osseointegration of dental endosseous implants.

REFERENCES1. Benic GI, Sancho-Puchades M, Jung RE, Deyhle H, Hämmerle CHF. In vitro assessment of artifacts induced by titanium dental implants in cone beam computed tomography. Clin Oral Impl Res 2013; 24: 378–383.2. Ritter L, Elger MC, Rothamel D, Fienitz T, Zinser M, Schwarz F, Zöller JE. Accuracy of peri-implant bone evaluation using cone beam CT, digital intra-oral radiographs and histology. Dentomaxillofac Radiol 2014 Jul; 43(6): 20130088. doi: 10.1259/dmfr.20130088.3. Kamburoglu K, Murat S, Kılıç C, Yüksel S, Avsever H, Farman A, and Scarfe WC. Accuracy of CBCT images in the assessment of buccal marginal alveolar peri-implant defects: effect of field of view. Dentomaxillofac Radiol 2014 May; 43(4): 20130332.doi: 10.1259/dmfr.20130332. 4. Schulze RKW, Berndt D, d’Hoedt B. On cone-beam computed tomography artifacts induced by titanium implants. Clin Oral Impl Res 2010; 21: 100–107.5. Omar G, Abdelsalam Z, Hamed W. Quantitative analysis of metallic artifacts caused by dental metallic restorations: Comparison between four CBCT scanners. Future Dental Journal 2016; 15e21.

* Iterative reconstruction refers to iterative algorithms used to reconstruct 2D and 3D images in certain imaging techniques.

** Algorithm of Feldkamp is a widely used filtered back-projection algorithm for 3D image reconstruction from cone-beam projections measured with a circular orbit of the x-ray source (Rodet et al., 2004)

*** DICOM (Digital Imaging and Communications in Medicine) is a standard for handling, storing, printing, and transmitting information in medical imaging.



have assessed the occlusal outcome of orthodontic therapy comparing early and late treatment5, patients treated by residents and specialists,6-11 longer and shorter treatment duration,12 and assessing performance of orthodontic advanced education programs13-14.

Postgraduate clinical training is an important component of orthodontic specialty education. Assessment of occlusal treatment results of comprehensive orthodontic therapy performed at an educational institute will always provide directions to future standards and improvement for postgraduate training. Such evaluations are also critical aspect of clinical audit15,16.

The aim of the present investigation was to evaluate the outcome of comprehensive orthodontic treatment performed by means of fixed appliance at an educational institute in Dubai, United Arab Emirates.

MATERIALS AND METHODSDuring the period of 2008-2012, Boston University-

Dubai (BU-D) established and administered a Master of Science in Orthodontics program. As part of this program, patients were treated in the Orthodontic Clinic by residents under faculty supervision. When BU–D discontinued its function, Dubai School of Dental Medicine (presently Hamdan Bin Mohammad College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences) was founded in 2012 and became responsible for the retention follow-ups as well as continuation of treatment of orthodontic patients of the former institution.

The records of all patients who received comprehensive orthodontic treatment by means of fixed edgewise appliances in maxillary and mandibular dental arches at BU-D were screened in order to identify those who fulfill the following inclusion criteria:

a. Healthy patients without a history of systemic diseases which may have an impact on orthodontic treatment (craniofacial anomalies, and cleft lip and/or palate).

b. Patients with permanent dentition at the beginning of their orthodontic therapy.

c. Patients with complete record files and study models of good quality.

Patients who had orthognathic surgery and patients with previous orthodontic treatment were excluded

from the study. Finally thirty (30) consecutive cases (22 females and 8 males) were included in the present study.

PAR and ICON indices were calculated at the beginning and end of orthodontic therapy using the initial and final sets of models, respectively. The first author, who blindly applied PAR and ICON indices and elaborated the data, was trained and calibrated in using them. All data were entered in an Excel file according to a specific format and patients’ data confidentiality was ensured.

Data were entered in computer using the Statistical Package for Social Sciences (SPSS), Windows version 20.0 (SPSS Inc., Chicago, Illinois, USA). Measurements were tested for normality by using Shapiro-Wilk test which was validated for small sample size. A cross-tabulated test was used to examine the independency between categorical variables and statistics was performed using chi-square test for assessing association. Where two or more continuous independent variables were examined, t-test and analysis of variance (ANOVA) were used if the data were normally distributed. Pearson coefficient of correlation was used to test the relations between variables. Paired t-test was used to assess the reliability and consistency of the investigator. P-value of less than 0.05 was considered significant in all statistical analyses.

To test the assumption that the investigator read consistently the materials, a calibration test was done by using the paired sample t-test after blindness and random selection were considered. As shown from the p-values of Table 1, the reliability of the investigator was confirmed.

RESULTS The average age of the sample at the beginning of

orthodontic treatment was 19.3 years (SD = 7.9 years). The average duration of orthodontic treatment (initial and final study models) was 17.7 months (SD = 5.8 months).

All variables, namely initial PAR, final PAR, initial ICON and final ICON were normally distributed.

Table 2 presents PAR and ICON values before and after orthodontic therapy. The mean value of initial PAR score was 19.4 (SD = 12.49), the mean value

INTRODUCTIONEvaluation of orthodontic treatment outcome is

important for justifying its necessity, its funding by private or third party providers, time invested by both patient and clinician, its effect on dentofacial esthetics, occlusal morphology and function as well as the long-

term retention and stability of the results. Orthodontic treatment outcome can be assessed by means of (a) occlusion, (b) function of the stomatognathic system, (c) facial esthetics and dental views of the patient and/or clinician, (d) short-term and long-term stability of the treatment occlusal outcome, and (e) iatrogenic treatment effects.1

Such highly subjective criteria, in many instances, need to be objectively evaluated in order to assess treatment outcomes. Occlusal indices can provide objective and quantitative assessment of occlusion. The most suitable and frequently used indices for assessing orthodontic treatment outcome are the Peer Assessment Rating (PAR) Index,2 the Index of Complexity, Outcome and Need (ICON),3 and the American Board of Orthodontics Objective Grading System (ABO-OGS).4

Utilizing these three indices, many investigations

Occlusal outcome assessment of orthodontic treatments performed at an educational institute in DubaiFadi Iyad Elshafee1, BDS, M.Sc.,Shazia Naser-ud-Din2, BDS, M.Sc., M. Orth. RCS(Ed),Amar Hassan Khamis3, Ph.D,Athanasios E. Athanasiou4, DDS, MSD, Dr. Dent.

1. Orthodontic Specialist, Fujairah, United Arab Emirates2. Former Associate Professor of Orthodontics, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates3. Associate Professor of Biostatistics, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates4. Dean and Professor, Department of Orthodontics, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates

AbstractThe aim of the study was to assess occlusal outcome of orthodontic treatments performed by postgraduate students

at an educational institute in Dubai. Consecutive patients’ files, including dental casts, were selected from the archives of the Boston University - Dubai

(BU-D) (2008-2012), which have been transferred to the Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences. The final sample was formed following application of certain inclusion criteria and consisted of 30 patients with permanent dentition who received comprehensive orthodontic treatment by means of fixed appliances in both dental arches. All pre- and post-treatment dental casts were blindely assessed by the first author (FIE) using the Peer Assessment Rating (PAR) and Index of Complexity Outcome and Need (ICON) indices. In order to test the intra-examiner reliability, the examiner re-assessed 15 cases, which were randomly selected from the original sample, one week after the initial examinations. Statistical analysis included descriptive statistics, paired t-test, Pearson coefficient of correlation and linear regression. The level of significance was set at p<0.05. The intra-examiner reliability was assessed using paired t-test and found high.

Results of the study indicated that occlusal outcome related to the orthodontic care provided was characterized by significant improvement. Mean PAR changed from 19.43 before treatment to 4.63 after (p<0.001). Mean ICON changed from 53.96 before treatment to 19.06 after (p<0.001). According to PAR 46.67% of patients “greatly improved” and 36.67% “improved”, respectively. According to ICON, 23.33% of patients “greatly improved”, 20% “substantially improved” and 36.67% “moderately improved”, respectively.

It may be concluded that examined patients treated at the Postgraduate Orthodontic Program of BU-D demonstrated significant improvement of their occlusion after orthodontic treatment.

Dental Research



presented “unacceptable treatment”.PAR and ICON changes were found statistically

significant (p<0.001) (Table 4).ICON and PAR improvements showed a strong

linear relation in correlation coefficient test (r=0.874 and p<0.001) indicating that whenever there is PAR improvement there will be ICON improvement as well (Fig. 1).

Based on PAR index interpretation, 46.67% of patients felt into the “greatly improved” category, 36.67% in the “improved” category, and 16.67% in “worse / no different” category.

Based on ICON index interpretation, 23.33% of patients felt in the “greatly improve” category, 20% in “substantially improved” category, 36.67% in “moderately improved” category, and 20% in “minimally improved” category.

PAR and ICON improvements were not related to treatment duration (p=0.195 and p=0.264, respectively) (Tables 5 and 6).

PAR and ICON improvements were found to be significantly related to initial PAR (r=0.738 and

p<0.001, respectively) and initial ICON (r=0.772 and p<0.001, respectively) (Figures 2 and 3).

Initial PAR and ICON values were significantly related to treatment duration (initial PAR, r= 0.415 and p=0.023, respectively; initial ICON, r=0.408 and p=0.025, respectively) (Figures 4 and 5).

Figure 6 shows that there is a statistically significant difference (p<0.001) between the three categories of PAR improvement in favor of the “greatly improved” group. It also shows a very low score of initial PAR in the “worse / no different” group.

DISCUSSION Measuring the outcome of orthodontic therapy

is an expanding field in orthodontics since it may contribute in justifying its need, cost, and commitment of all parties involved. PAR and ICON indices are regarded as essential tools, not just as self evaluation instruments, but also as means for evaluating large samples of patients. They could be used for quality control and setting standards as well as for educational improvement.

Table 5. Correlation between PAR improvement and treatment duration.

PAR Improvement

Duration (months)

PAR Improvement

Pearson Correlation

1 0.243

Sig. (2-tailed)

0.195

Duration (months)

Pearson Correlation

0.243 1

Sig. (2-tailed)

0.195

Table 6. Correlation between ICON improvement and treatmentduration

ICON Improvement

Duration (months)

ICON Improvement

Pearson Correlation

1 0.211

Sig. (2-tailed)

0.264

Duration (months)

Pearson Correlation

0.211 1

Sig. (2-tailed)

0.264

of final PAR score was 4.63 (SD = 2.47), the mean value of initial ICON was 53.96 (SD = 23.78) and the mean value of final ICON was 19.06 (SD = 6.19), respectively.

The rate value of PAR reduction (improvement) was 76.17% (Table 3).

Based on PAR index interpretation, PAR treatment

acceptability descriptive analysis showed that 17 cases (56.67%) were treated to “ideal occlusion”, 12 cases (40%) to “acceptable occlusion” and only one case (3.33%) presented “unacceptable treatment”.

Based on ICON index interpretation, ICON treatment analysis shows 29 cases (96.7%) had “acceptable treatment” while only one case (3.3%)

Table 1. Results of the reliability test of consistency of investigator’s readings by using paired t-test.

Table 2. PAR and ICON values before and after treatment. Table 3. Calculation of rate of PAR reduction.

PairsMean

difference

Std. Error Mean

95%CIp-value

Lower UpperInitial PAR1 &

Initial PAR2 -0.13 2.13 -1.26 1.0 0.817Final PAR1 & Final

PAR2 -0.07 1.07 -0.69 0.55 0.807Initial ICON1 &

Initial ICON2 -0.94 5.11 -3.66 1.78 0.474Final ICON1 &

Final ICON2 -0.71 1.86 -1.79 0.36 0.174

Variable Mean SD

Initial PAR 19.43 12.49

Final PAR 4.63 2.47

Initial ICON 53.96 23.78

Final ICON 19.06 6.19

Table 4. Difference between initial PAR and final PAR values as well as between initial ICON and final ICON values evaluated by means of paired t-test.

Paired difference

t Sig. (2-tailed)

Mean SD SE95% Confidence Interval of the

Difference

Lower Upper

Initial PAR - Final PARInitial ICON - Final ICON

14.834.9

12.8124.22

2.334.42

10.0125.85

19.5843.94

6.327.89

.000

.000


Fig. 2. Correlation between PAR improvement and initial PAR score.

2

Figure 2. Correlation between PAR improvement and initial PAR score.

PAR

impr

ovem

ent

Initial PAR

PAR

impr

ovem

ent

Initial PAR

were used in order to examine it from different points of assessment. Furthermore, advantages in one index could compensate disadvantages of the other index. For example, PAR is not critical of final outcome because of its undue leniency on poor finishes and undue harshness on treatment with limited aims. ICON seemed to require more stringent standard than PAR to attain “greatly improve” categorization19. Also PAR can give more detailed view for single component, for example the overjet, while ICON addresses esthetics by including an esthetic component in addition to the occlusal component.

The mean initial PAR score in this study was 19.43. This is close to the residents groups’ scores of another report (21.0 and 21.3, respectively)5 and relatively smaller than the scores of other studies (23.8, 28.7 and 23.83, respectively)20-22. Mean final PAR score was 4.63, which is smaller than PAR scores found in other reports (8.3, 10.2 and 8.4, respectively)5 (6)21, similar (4.4)20 and larger (1.7)22.

The percentage of PAR reduction was 76.17%, which is very close to other similar investigations (76.7 and 77.8, respectively)5,20 but lower from another one’s

score (86%)22. Although the final PAR score indicated that 17

cases (56.7%) reached “ideal occlusion” and 12 cases (40%) reached “acceptable occlusion”, still this finding is not sufficient to show a high standard of treatment because the percentage of cases assigned to “worse / no different” was above 5%.

For more understanding of the results of PAR scores for this sample, differentiation should be made among three terms namely categories of improvements, acceptability of occlusion and standards of treatment.

Categories of improvement depend on the percent of reduction from initial score to final score or the amount of points reduced due to orthodontic treatment. If the amount of PAR score reduction is 22 points or more, the case will classify as “greatly improved”, and it will classify as “improved” if the percentage of PAR reduction is equal or greater than 30%. If the percentage of PAR reduction is less than 30% the case will lie under “worse or no different”.

In the present sample, and because of low initial PAR, the total reduction points were small leading to high number of cases (five cases) which were “worse or

The present study assessed the occlusal outcomes in patients treated orthodontically by residents at a higher education institution in order to examine the quality of treatment delivered and for benchmarking standards. Moreover, this study could serve as a baseline for comparing subsequent treatment results as part of internal clinical audit in the institution which is presently in the place of BU-D.

The sample that has been used in this study consisted of patients who were treated with fixed appliances in maxillary and mandibular dental arches by means of the straight wire technique. After applying inclusion criteria, the total cases were 30, which are regarded as a relatively small size sample. This was due to the limited period that the orthodontic program existed in BU-D and the small number of orthodontic residents who attended it.

The first author (FIE) blindly scored the casts by assigning a random number to each set of casts without being aware of patients’ details and stage of therapy. Also the computer program selected randomly 30 sets (16 initial and 14 final) to be re-examined for assessing method’s error. The error of the method was assessed

by measuring the models after one week for a washout period. The results showed significant correlation between the second and first reading thus indicating reliability of measurement. It should be noted that the scoring investigator was calibrated in using the indices by attending a relevant course by the innovators of PAR and ICON indices.

These two indices are internationally acceptable and regarded valid and reliable. PAR index has shown high validity and reliability17. ICON has shown validity in measuring outcome and complexity18.

There are advantages in using both indices in a study like the present one. PAR assessed the cases from the aspect of how much these cases deviated from normal occlusion before treatment and described the improvement that took place by means of percentage of PAR reduction and PAR acceptability, thus assisting in setting and examining treatment standards. On the other hand, in addition to describing the outcome, ICON evaluated the degree of treatment need and complexity of the case before treatment. Therefore, to better describe the occlusal outcome of cases treated orthodontically by the BU-D residents, both indices

Fig. 1. Correlations between PAR improvement and ICON improvement.

1

Figure 1. Correlations between PAR improvement and ICON improvement.

ICON improvement

PAR

impr

ovem

ent

PA

R im

prov

emen

t

ICON improvement


Fig. 3. Correlation between ICON improvement and initial PAR score.

3

Figure 3. Correlation between ICON improvement and initial PAR score.

Initial PAR

ICO

N im

prov

emen

t

ICO

N im

prov

emen

t

Initial PAR

Fig. 4. The relation between initial PAR and treatment duration.

4

Figure 4. The relation between initial PAR and treatment duration.

Initi

al P

AR

Duration (months) Duration (months)

Initi

al P

AR

no different” and resemble 16% of the cases.The other manner by which PAR assesses treatment

outcomes is by noting the acceptability of treatment. In this aspect, there are three categories “ideal” occlusion if the final PAR score is less than 5, the second category is “acceptable” occlusion if the final PAR score is from 5 to 10, and “unacceptable” occlusion if the final PAR score is more than 10.2,17. Younis proposed a value of 15 rather than 10 for the case to be “acceptable” occlusion23.

These two ways of assessing the final results (i.e. categories of improvement and acceptability of occlusion) sometimes create confusion.

In the present study, it was interesting to note that five patients who ended with final PAR scores of 2, 9, 9, 5 and 5, respectively, were actually from the improvement criteria and categorized as “worse / no different”. On the other hand, from the acceptability criteria points of view, four of these cases were under “acceptable” occlusion, and the case with final PAR score 2 was under “ideal” occlusion. There was also a case with final PAR score 12 assigned to the “improved” category from the improvement point of view, and “unacceptable” from the acceptability point of view.

The third way to interpret PAR scores is standards of treatment. It has been proposed that to reach orthodontic treatment of high standards, the mean PAR reduction should be greater than 70%, the number of cases allocated to the “worse / no different” category should be negligible (less than 5%), and the number of cases allocated to “greatly improved” should be high (for example greater than 40%)17.

In the present sample, the mean PAR reduction was 76.17%, the number of cases allocated to the “worse / no difference” category was 16.67% and the number of cases allocated to “greatly improved” category was 46.67%.

Therefore, based on these criteria and because the number of cases allocated to “worse / no different” category is 16.67%, the treatment accomplished for this sample did not reach the high standard orthodontic treatment although PAR reduction was above 70% and cases felt in the “greatly improved” category was above 40%.

Considering the percentage of PAR reduction as the

only criterion to reflect on the standards of treatment, the actual quality of orthodontic treatment that had been provided to these patients may not be evident, especially if treated cases had low initial PAR score. It should be noted that the percentage of reduction depended on the initial PAR score, and whenever the initial PAR score was low (i.e. less than 22 points) the case could never be finished to the “greatly improve” category. This is demonstrated well in Figure 2 that shows by means of linear regression analysis between initial PAR and PAR improvement that 54.5% of PAR improvement explained by initial PAR measurement. It is also demonstrated in Figure 3 that shows from linear regression analysis between initial PAR and ICON improvement that 59.5% of ICON improvement explained by initial PAR.

It may be suggested that for more reliable standards of treatment, more emphasis should be given to the final PAR score in addition to the initial PAR score and amount of PAR reduction.

As both PAR and ICON indices showed high validity and reliability as assessed by British and an international panel of orthodontists, it is logic to show high correlation between both PAR improvement and ICON improvement scores.

The mean value of initial ICON score for the present study was 53.96, which indicates moderate level of complexity similar to a mixed dentition sample in which it was 54.923 in comparison to another one that was 6925. Our score of 53.96 is above the ICON’s cutoff for “treatment need”, which means that these cases needed treatment, while the mean of final ICON score was 19.06, compared to 15.825 and 33.6 in a mixed dentition sample24.

This final ICON score places the sample under the “easy” group of complexity and “no need” group for treatment need.

The outcome of orthodontic treatment of the present sample, according to ICON, showed that 20% “minimally improved”, 20% “substantially improved”, 23.33 “greatly improved” and 36.67 “moderately improved” thus verifying that all cases of this sample collectively presented different grades of improvement.

All the cases finished with acceptable occlusion except one which is the same case that showed unacceptable occlusion according to PAR index.


PAR and ICON improvements were not related to treatment duration and this means that whether the orthodontic treatment finished in a shorter or longer duration it did not affect PAR or ICON improvement.

Regardless of the relatively small sample size that was examined in this investigation, there was a significant difference between the initial and final PAR and ICON scores indicating that the BU-D orthodontic residents were able to significantly improve the occlusion of their patients.

CONCLUSIONS Analysis and interpretation of the outcome of

orthodontic therapy delivered by BU-D residents (by means of the PAR and ICON indices) conclude the following:

1- According to PAR index scoring, 83.34% of patients were in the “improved” and “greatly improved” categories and only 16.67% were in the “worse or no different” category.

2- According to ICON index scoring, all patients showed various degrees of improvement.

3- There was a strong correlation between initial PAR score mean and PAR reduction that justifies the use of initial PAR as a good predictor factor for the final treatment acceptability.

4- The length of the treatment duration did not affect occlusal outcome.

REFERENCES 1. Berg R. Evaluation of orthodontic results - a discussion of some methodological aspects. Angle Orthod 1991;61:261-6.2. Richmond S, Shaw WC, Roberts CT, Andrews M. The PAR Index (Peer Assessment Rating): methods to determine outcome of orthodontic treatment in terms of improvement and standards. Eur J Orthod 1992;14:180-7.3. Daniels C, Richmond S. The development of the index of complexity, outcome and need (ICON). J Orthod 2000;27:149-62. 4. Casko JS, Vaden JL, Kokich VG, Damone J, James RD, Cangialosi TJ, Riolo ML, Owens SE Jr, Bills ED. Objective grading system for dental casts and panoramic radiographs. Am J Orthod Dentofacial Orthop 1998;114:589-99.5. Firestone AR, Häsler RU, Ingervall B. Treatment results in dental school orthodontic patients in 1983 and 1993. Angle Orthod 1999; 69:19-26.6. Dyken RA, Sadowsky PL, Hurst D. Orthodontic outcomes assessment using the peer assessment rating index. Angle Orthod 2001;71:164-9.

7. Mascarenhas AK, Vig K. Comparison of orthodontic treatment outcomes in educational and private practice settings. J Dent Educ 2002;66:94-9.8. Yang-Powers LC, Sadowsky C, Rosenstein S, BeGole EA. Treatment outcome in a graduate orthodontic clinic using the American Board of Orthodontics grading system. Am J Orthod Dentofacial Orthop 2002;122:451-5.9. Cook DR, Harris EF, Vaden JL. Comparison of university and private-practice orthodontic treatment outcomes with the American Board of Orthodontics objective grading system. Am J Orthod Dentofacial Orthop 2005;127:707-12.10. Tofeldt LN, Johnsson AC, Kjellberg H. Evaluation of orthodontic treatment, retention and relapse in a 5-year follow-up: a comparison of treatment outcome between a specialist and a postgraduate clinic. Swed Dent J 2007;31:121-7.11. Mislik B, Konstantonis D, Katsadouris A, Eliades T. University clinic and private practice treatment outcomes in Class I extraction and nonextraction patients: A comparative study with the American Board of Orthodontics Objective Grading System. Am J Orthod Dentofacial Orthop. 2016;149:253-8.12. Vu CQ, Roberts WE, Hartsfield JK, Ofner S. Treatment complexity index for assessing the relationship of treatment duration and outcomes in a graduate orthodontics clinic. Am J Orthod Dentofacial Orthop 2008;133:9.e1-13.13. Santiago JJ, Martínez CJ. Use of the objective grading system of the American Board of Orthodontics to evaluate treatment at the Orthodontic Graduate Program Clinic, University of Puerto Rico, 2007-2008. Puerto Rico Health Sci J 2012;31:29-34.14. Pariskou AG. Occlusal outcome assessment of orthodontic treatment performed at the postgraduate orthodontic program of Aristotle University of Thessaloniki. Thessaloniki: Master of Science in Orthodontics, Aristotle University of Thessaloniki, 2013.15. Eliades T, Athanasiou AE. Advanced orthodontic education: evolution of assessment criteria and methods to meet future challenges. Angle Orthod 2005;75:147-54.16. Athanasiou AE, Darendeliler MA, Eliades T, Hägg U, Larson BE, Pirttiniemi P, Richmond S, Soma K, Vardimon A, Wiltshire W. World Federation of Orthodontists (WFO) guidelines for postgraduate orthodontic education. World J Orthod 2009;10:153-66.17. Richmond S, Shaw WC, O’Brien KD, Buchanan IB, Jones R, Stephens CD, Roberts CT, Andrews M. The development of the PAR Index (Peer Assessment Rating): reliability and validity. Eur J Orthod 1992;14:125-39.18. Savastano NJ, Firestone AR, Beck FM, Vig KW. Validation of the complexity and treatment outcome components of the index of complexity, outcome, and need (ICON). Am J Orthod Dentofacial Orthop 2003;124:244-8.19. Fox NA, Daniels C, Gilgrass T. A comparison of the index of complexity outcome and need (ICON) with the peer assessment rating (PAR) and the index of orthodontic treatment need (IOTN). Br Dent J 2002;193:225-30.20. Richmond S, Andrews M. Orthodontic treatment standards in Norway. Eur J Orthod 1993;15:7-15.

Fig. 5. The relation between initial ICON and treatment duration.

Fig. 6. Simple box plot between initial PAR and PAR grades.

5

Figure 5. The relation between initial ICON and treatment duration.

Initi

al IC

ON

Duration (months)

Initi

al IC

ON

Duration (months)

6

Figure 6. Simple box plot between initial PAR and PAR grades.

Initi

al P

AR

PAR grades

Initi

al P

AR

PAR grades

7170

INTRODUCTIONAccording to the World Health Organization (WHO)

criteria, patients who have lost all of their teeth, suffer from a chronic condition called oral disability.1 One of the popular treatments for this chronic condition is removable complete dentures.2 Oral rehabilitation with well-made complete dentures can restore a sense of normalcy and an acceptable self-esteem.3

Complete denture therapy is the replacement of lost natural dentition with an artificial esthetic, mechanical, and functional prosthetic medical device.4,5 According to the National Institute of Aging (2014-2015), average life expectancy increased from 50 years in the late 20’s to over 84 years, and aging edentulous patients are expected to wear their dentures for a longer period of time, facing a complete disappearing of primary support surface due to loss of alveolar bone and destruction of basal bone (Fig. 1). These changes are accompanied by a natural reduction in neuromuscular activities and strength, not to forget that deterioration in the overall medical health can worsen the situation.6 These neuromuscular forces vary in magnitude and direction in different areas of oral cavity, and with aging.7 The goal of modern complete dentures is not only to replace teeth but also to compensate for the loss of supporting structures and impaired functions. Modern prostheses must occupy and restore the "volume - space - zone"1,2,33 within the edentulous oral cavity, including teeth, hard

The “Neutral Zone” concept in removable complete denture fabrication: A salvation technique for severely resorbed mandibular ridges.Robert G. Mokbel1, Dr. Chir. Dent., Dr. Sc. Odont., Tony Daher2, Dr. Chir. Dent., CES Fixed Prostho., CES Remov. Prostho., PG Cert. Prostho., MS (Education), FACP, FICP, FICD, MAO, Diplomate of the American Board of Prosthodontics, Fellow of Pierre Fauchard Academy,Joseph J. Massad3, DDS, MAGD, FACD, FICD, MIA Dent. Fac. Esth., Fellow of Pierre Fauchard Academy

1. Clinical Associate Professor, University of Southern California, Herman Ostrow School of Dentistry, Los Angeles, California, USA2. Co-Director of Global Dental Implant Academy - GDIA, La Palma, California, USA, and Former Associate Professor, Loma Linda University School of Dentistry, Loma Linda, California, USA3. Clinical Associate Professor of Prosthodontics, University of Tennessee Health Science Center -UTHSC- College of Dentistry, Memphis, Tennessee, and, Adjunct Associate Professor, Department of Restorative Dentistry, Loma Linda University School of Dentistry, Loma Linda, California, USA Memphis.

Removable Prosthodontics

AbstractThe Neutral Zone-NZ- is the specific area of the mouth where ,during physiological function,tongue forces pressing

outwards are neutralized by cheeks and lips forces pressing inwards. The neutral zone impression technique is a special technique that relies on muscles balance , the muscular oral control being the major retentive and stabilizing factor of complete dentures during oral functions.

A denture shaped by NZ technique ensures a better harmony of oral muscular forces , an improved retention and stability of the complete denture , a reduced food trapping adjacent to molar teeth, and good esthetics due to facial support.

The aim of this article is to address the NZ technique to general practitioners and prosthodontists who need to consider this alternative impression technique in the fabrication of mandibular complete dentures on highly resorbed residual ridges. This technique is particularly useful and indicated when placement of dental endosseous implants is not possible.

Dental clinicians are advised to incorporate this technique into their daily routine treatment of totally edentulous patients.

21. Birkeland K, Furevik J, Bøe OE, Wisth PJ. Evaluation of treatment and post-treatment changes by the PAR Index. Eur J Orthod 1997;19:279-88.22. Onyeaso CO, BeGole EA. Orthodontic treatment - improvement and standards using the peer assessment rating index. Angle Orthod 2006;76:260-4.23. Younis JW. Validation of the Index of Orthodontic Treatment Need in the United States. Pittsburgh: Master of Science, Univeristy of Pittsburgh, 1995.23. King GJ, Brudvik P. Effectiveness of interceptive orthodontic treatment in reducing malocclusions. Am J Orthod Dentofacial Orthop 2010;137:18-25.25. Richmond S, Aylott NA, Panahei ME, Rolfe B, Tausche E. A 2-center comparison of orthodontist’s perceptions of orthodontic treatment difficulty. Angle Orthod 2001;71:404-10.

Corresponding author:Athanasios AthanasiouAthanasios.Athanasiou@mbru.ac.aewww.mbruniversity.ac.ae




Orthodontists recognized the importance of this space: an imbalance between both buccinator muscles and the tongue will move teeth within dental arch, and can cause a failure of orthodontic treatments. When teeth are lost, this "give and take" between the muscles does not disappear; Trying to replace teeth with complete dentures should not ignore muscular dynamics, especially if the stability of dentures is compromised by continuous resorption as, of the residual ridges.4,19

Any attempt to stabilize dentures must indeed take into consideration the position and the tension of muscles at rest, as well as during function (mastication, phonation, deglutition, and facial expression)28. Tongue position and lateral border of the tongue must function

in a way not to dislodge lower denture from its base, especially during the placement of bolus on occlusal table during mastication.15 Buccinator and orbicularis oris muscles should act to stabilize the denture in its position (Fig. 4). Conventional denture teeth are supposedly set up in the volume occupied previously by teeth,12,13,20 over the crest of the ridge,21,22 they have

Fig. 3. Equilibrium of the forces generated by A) Cheeks and labial muscles, against B) Tongue muscles.

Fig. 4. Buccinators (B) and orbicularis oris (OO) muscles should stabilize mandibular denture in place.

Fig. 5. Neutral Zone formed by molding the grey modeling plastic by the action-reaction of tongue and cheeks and lip muscles. In that zone, prosthetic teeth will be arranged to improve the stability of mandibular denture.

Fig. 6. Optimally contoured polished external denture surfaces.

3A 3B

B

B

B

B

OO

OO

and soft tissues, and allow proper function (Figs. 2A, 2B). Thus, the treatment must evolve to include a 3 dimensional (3-D) approach.8

There are many acceptable techniques used in the construction of dentures in private practice. Some will end up in a successful or unsuccessful outcome. We often hear practicing dentists complaining: “denture treatment is very frustrating; we have to deal with so many adjustments visits!” “unsuccessful result is always when the mandibular ridge is very resorbed,” “We have stopped treating denture patients because we could not help them”.9

Fabricating removable complete dentures is a complex process, but in the mind of most clinicians, it is just a matter of replacing missing teeth. To the contrary, complete dentures should replace all missing oral structures and accommodate changes in oral neuromuscular activities.6 It is widely known that denture base is considered the first surface of complete dentures, occlusal surface is the second surface, but very few dentists pay attention to the third one, which is the polished external surface that is surrounded by a group of strong muscles.10 Instability of poorly fitting complete dentures can be attributed to a multitude of factors such as poor reproduction techniques of supporting tissues, inadequate tooth arrangement, and poor occlusal scheme.11,12,13 As the ridges continue to deteriorate, orofacial and antagonistic lingual muscles play a larger role in this equation. Prosthetic external surfaces have to be molded to conform physiologically and functionally in order to compensate for changes in muscles tonicity.

However, because of the confusion that exists in treating completely edentulous patients, especially in the case of a very resorbed mandibular ridge, it is important to recognize the importance of the "Neutral Zone" -NZ- record and the external surfaces impressions. This becomes the more important factor in denture’s stability, thus the traditional techniques for making impressions need to be changed.

The purpose of this paper is to describe these 2 additional techniques that should be incorporated in denture's fabrication steps: 1) making a neutral zone record and 2) making an external surfaces impression.

THE COMPLETE DENTURE SURFACESThe 3 surfaces of a complete denture: teeth,

base, and polished surfaces, have to confine and function within the Neutral Zone,13,14 or the prosthetic space.15,16,17,18 The neutral zone is not a new concept in dentistry7,35. The concept of neutral zone is rooted in the idea that teeth erupt into a space surrounded by a balance between opposing oral forces5 (Figs. 3A,B).

Fig. 1 Excessive resorption of a mandibular ridge.

Fig. 2. A) excessive loss of oral structures. B) adequate support of the oral tissues with newly fabricated removable complete dentures.

2.A

2.B


Fig. 7. A) The base-plate is stabilized by relining it on the master cast with zinc oxide material. B. 2mm width of red stick compound is luted onto the baseplate.

Fig. 10. Making the neutral zone clinically. A) Softening of the record in the water bath. B) Molding the record by asking the patient to sip hot water and to swallow and then cold water to cool the record.

Fig. 9. Neutral zone fabrication in the lab. A) Hot red compound is placed over the base-plate to secure the grey compound in place. B) The height of the record is established from the measurement of the lower lip at rest with the "Massad lip ruler". C) "Massad lip ruler" measurement of the height of the lower lip at rest.

Fig. 8. A) Soft liner placed over the red compound and molded phonetically in patient’s mouth. B. The neutral zone record finished and placed over the master cast. C. Lab silicon putty indexes are made and used as a guide when setting up the prosthetic teeth.

7A 7B

8C

9C9B

10B

9A

10A

8B8A

validity when the ridge and other landmarks (retromolar pad) can be easily identified, such in recent extraction cases or in immediate dentures. Pound23 and Weinberg11 recommended the use of landmarks on mandibular ridge, such as the Pound triangle bound by the buccal and lingual aspects of retromolar pad extending to the canine. Other authors expanded on these landmarks as well25 while Lammie26 claimed that posterior teeth should be set up on buccal shelve to give more room for the tongue.26

Ideally, mandibular posterior teeth should be arranged in a central position within the neutral zone, in a manner that allows tongue and cheeks to function and improve denture's stability during occlusal loading, and during normal function (Fig. 5). In this scenario, forces applied by the tongue on dentures are neutralized or countered by the resistance of cheeks and lips7,27 on optimally contoured polished external denture surfaces (Fig. 6). This may facilitate retention and stability of the prosthesis.28

Dental endosseous implants improve stability and retention of dentures, but not every patient can have dental implants. Nevertheless, the teeth and the polished surfaces10 of dentures must stay in harmony with the patient's musculature in order to provide a comfortable denture. Many clinical techniques have been described for the registration and improvement of tooth position and the polished surfaces of the dentures.28,29

NEUTRAL ZONE RECORDINGS Several techniques and materials have been

described to register the prosthetic space. They all require fabrication of a stable base-plate and placing a registration material in mandibular edentulous space while the patient is activating his cheeks and remaining muscles.

A - Phonetic techniqueKlein29 was one of the first who described the

“Piézographie” technique which is performed at rest, using the a 2mm occlusal rim with a tissue conditioner (Hydrocast®); the patient does not have to move his tongue or his/her lips, and if the tongue is retracted, Klein recommended educating it using phonetics (SE, DE, TE, and SIS); the patient can then rest his/her tongue and lips for 5 minutes before removing the

recording from the mouth. No opposing base-plate is present on maxillary arch during this registration.

In our personal doctoral thesis,30 we described (in 1982) an improved 2-steps phonetic technique for recording the neutral zone.

1- A base-plate with a thin occlusal rim of 2mm width is fabricated with a red impression compound (Impression compound, Kerr). The base-plate is stabilized on the cast using a zinc oxide impression material (Figs. 7A, 7B).

2- The clinician should try the record base in patient's mouth and observe for any contacts of the occlusal rim with the borders of the tongue and the cheeks and lips at rest, the occlusal rim should extend 2 mm above the lower lip, at rest.

3- Also, one should verify that the tray is stable, remove any interferences using a Parker blade knife, and if necessary, warm the occlusal rim using a handheld Torch (Hanau, Dentsply) in suspicious areas and place back in patient's mouth, ask the patient to open, close, and repeat the phonemes “SIS, DE, TE, SE” as described by Klein in his thesis29 (repeat as needed). This will help mold the first part of the “prosthetic space” (R. Mokbel30,31). The use of occlusal rim helps stimulating the tongue in a more physiological position by recalling the memory of contact with teeth. The occlusal rim helps carrying the additional registration material in the mouth without slumping.

4- Mix the tissue conditioning material (Visco-Gel®, Dentsply) to a medium consistency. Apply the tissue conditioner generously with a spatula on occlusal rim, on both sides, and then place in patient's mouth. The soft material can also be injected with a syringe. This technique uses phonetics (ask the patient to repeat the French sounds “Sis, De, Te, Se”, repeat the procedure for 5 minutes, remove from the mouth, and examine the registration). The sound “Sis” presses tongue horizontally against mandibular teeth and activates buccinator muscles30, while the phonemes “Deu”, “Teu” and “Seu”, push lips against front teeth in opposite direction.

5- Mark the position of maximum concavity with a marker to highlight borders of tongue. In this technique, presence of occlusal rim is necessary to support the Visco-Gel®.

6- In the laboratory, fabricate a lab. silicone putty


index to transfer neutral zone on the cast. This will represent the 3D volume space necessary to setup the teeth. Adapt the putty on each side of the recording (lingual and buccal), the putty represents the tongue on one side and the muscles of the cheeks and lips on the opposite side (Fig. 8)3,19.

The advantage of this technique30 is the determination of vertical position of occlusal plane as well as the

horizontal position of the teeth.

B - Swallowing techniqueBeresin and Schiesser7 described a technique to

register and transfer the volume of neutral zone, using modeling plastic impression compound over a record base-plate during different functions. The impression of the registered neutral zone is then transferred using

Fig. 13 A) View of the neutral zone surrounded by labial, buccal, and lingual putty indexes on master cast. B) The brown areas show the action of buccinator muscles, the green area shows the action of orbicularis oris muscles, the black area shows the action of tongue muscles.

Fig. 14 A) Placing the light viscosity of PVS after removing some of the festooned wax. B) Showing buccal and labial external surfaces molded. C) Showing lingual external surfaces molded. D) Blending the cervical pink wax with the PVS after removing PVS from over teeth. The mandibular trial denture is now ready to be flasked and finished.

13A 13B

14A

14C

14B

14D

Fig. 11. A) the outward actions of the tongue and the inward actions of the cheeks are molding the warm grey compound to form the neutral zone or the prosthetic space. B) The molded neutral zone recorded the action of tongue muscles, cheeks muscles, and lips muscles. C,D) The prosthetic teeth are set according to the neutral zone on the finished mandibular denture.

Fig. 12. A) the neutral zone molded in patient’s mouth showing the excess of grey compound that is needing to be trimmed. B. Lingual view of the neutral zone record showing the flared area molded by the action of tongue. C) The black line shows the excess of modeling plastic impression grey compound displaced superior to the intended occlusal plane during the recording procedure that needs to be eliminated. D) The trimmed record ready to be sent to the laboratory.

11A 11B

11C

12A

12C

11D

12B

12D


C - Forming the Polished (External) Surfaces, also known as the Cameo Surfaces8,28

1- After the approval of trial dentures by the dentist and the patient trial, the preparation for the cameo surfaces impressions starts. The purpose of such impression is to define denture polished surface contours within the neutral zone.

2- Carefully remove all baseplate wax apical to denture teeth on facial and lingual aspects of mandibular trial denture. This will leave a slight flat to concave surfaces. Inform the patient about the movements that must be made during impression process. Practice will be required from the patient to do the repeated orofacial movements prior to making impressions.

3- Apply vinyl polysiloxane (VPS) adhesive (Caulk Tray Adhesive; Dentsply Caulk, Milford, Del, USA) and low-viscosity VPS (Aquasil Ultra LV Fast Set; Dentsply Caulk, USA) onto lingual surfaces of mandibular trial denture where wax was removed (Figs. 14 A, 14 B, 14C, 14D).

4- Use cheek retractors (Columbia Cheek Retractors; Hu-Friedy Mfg Co, Inc, Chicago, USA) to retract cheeks and lips and to aid in the placement of trial dentures (be careful not to displace the impression material).

5- Place the trial denture and instruct the patient to extend the tongue and move it from side to side, and then ask the patient to sip water and to swallow several times.

6- Trim excess impression material from the trial denture. Carefully eliminate all material covering the denture teeth (Fig. 14D) and get ready to impress labial and buccal cameo surfaces.

7- Apply VPS adhesive (Caulk Tray Adhesive; Dentsply Caulk, Milford, Del, USA) and low-viscosity VPS (Aquasil Ultra LV Fast Set; Dentsply Caulk) onto labial and buccal surfaces of the mandibular trial denture where wax was removed.

8- Use cheek retractors (Columbia Cheek Retractors; Hu-Friedy Mfg Co, Inc, Chicago, USA) to aid in the placement of trial dentures.

9- Place the trial denture intraorally and be careful not to displace impression material.

10- Place the trial denture and instruct the patient to puck the lips forward like kissing and then to smile like he/she is happy, and then ask the patient to sip water and to swallow several times.

11- Trim excess impression material from the trial denture. Carefully eliminate all material covering the denture teeth (Fig. 14D).

12- Remove the trial denture and examine denture flange dimensions and extensions. Adjust record base and wax contours, and then send to the laboratory where denture cameo surfaces will be refined by blending the wax with the PVS material(Fig. 14D). The denture then will be invested, processed, finished, and polished using conventional methods32,33,34 (Fig. 6).

CONCLUSION This paper addresses a clinical technique intended

for the physiologic registration of optimal denture teeth positions and denture base contours. Determination of the "Neutral Zone" and the establishment of proper contoured cameo surfaces, are most useful in enhancing the stability of mandibular denture with minimum or no alveolar ridge remaining, and making wear of dentures more comfortable. The registration of polished surfaces or cameo surfaces, produces surfaces that are not conventional; These surfaces are convex, concave, or mixed, according to the tonus of oral musculature. They also provide more support and better facial seal to the cheeks and the lips, rendering the dentures more comfortable and more functional.

The "neutral zone philosophy" follows a concept that advocates considering, for each individual edentulous patient, a specific area in the denture space, where muscular function will not unseat the denture and where tongue forces are neutralized by forces generated by cheeks and lips.

Clinicians are advised to incorporate this technique into the routine prosthodontic management of totally edentulous patients in order to improve stability and retention of lower denture and minimize food retention.

REFERENCES1. World Health Organization. International Classification of functioning, disability and health: ICF. Geneva: WHO, 2001.2. Felton DA. Edentulism and Comorbid Factors. J Prosthodontics 2009; 18:88-963. Roumanas ED. The Social Solution-Denture Esthetics, Phonetics, and Function. J Prosthodont 2009;18:112-115.4. Atwood DA. Reduction of residual ridges: a major oral disease entity. J Prosthet Dent 1971;26:266-79.

a lab. silicone putty matrix to perform the denture teeth set up. During the trial denture visit, an additional impression is made using either zinc oxide and eugenol paste or tissue-conditioning material to register external surfaces of the denture on facial, lingual, and palatal surfaces of the trial denture. This final impression is made to record functional tissue interactions with denture surfaces. The patient is instructed to close his mouth, purse the lips as in sucking, and then swallow.7,28

Another variant of Beresin and Schiesser technique is the Massad technique8,28:

1- In the laboratory, fabricate the mandibular neutral zone record base and rim, and construct mandibular record base using conventional methods.32 Apply hot red modeling plastic impression compound (Impression Compound; Kerr Corp, Orange, California, USA) to the record base to facilitate adhesion of the rim. Seal the edges of the recording rim to the record base using a heated spatula. In a water bath set to 170°F (76,6oC), warm 3 sticks of grey modeling plastic impression compound (Impression Compound; Kerr Corp), knead the material thoroughly, and adapt it to the record base, forming a recording rim. The anterior height of the grey compound rim is done according to the measurement of the lower lip line giving by the "Massad ruler", and the posterior height of the compound rim is at half way of the retromolar pad. The rim width is 8mm anteriorly and 10mm posteriorly. This thickness is important to allow enough material to raise up to above tongue's border (Figs. 9A, 9B, 9C).

2- In the clinic, the neutral zone record9 is heated in a water bath of 170°F, then placed in patient's mouth. The patient will be asked to sip and swallow hot water for 4-5 times, then cold water is given before removing the record out of the mouth (muscles of cheeks and lips move inward while tongue's muscles move outward). This neutral zone record is a must when mandibular ridge is very low (very resorbed) or non-existing. Use of the neutral zone method to identify and register the anatomy and physiology that impact prosthesis stability may result in improved prosthodontic therapy for patients (Figs. 10A, 10B).

3- In the maxilla, it is important not to place either a record base or the existing maxillary denture during clinical registration of mandibular neutral zone. This will avoid any compressive interferences from

opposing ridge, encountered during the functional recording procedure.

4- Since the swallowing maneuver is used during registration of neutral zone, patients with decreased occlusal vertical dimension typically produce horizontally excessive and vertically reduced neutral zone records.28 Hence, it is important to reestablish an appropriate vertical jaw relationship, and deprogram muscles responsible for mandibular posture with effective clinical deprogramming techniques that have been previously described for complete denture patients.28

5- Coordinated cheeks muscles and tongue's activity plastically shape the rim to form the neutral zone (Figs. 11A, 11B, 11C, 11D).

6- When the neutral zone record has cooled and hardened, remove and inspect the record for accuracy and completeness (Figs. 12A, 12B, 12C, 12D). Eliminate excess modeling plastic impression compound displaced superior to the border of the tongue, to the intended occlusal plane during the recording procedure with a Bard-Parker® blade and repeat the recording process to ensure proper recording of the entire neutral zone.

7- In the laboratory, the technician will develop the lingual neutral zone index. The neutral zone record is seat back on the mandibular definitive cast. Prepare laboratory putty (Poly V Putty; Accurate Set, Inc, Newark, NJ, USA) to a workable consistency and completely fill the tongue space with it to the lingual contours of neutral zone record, and up to the level of the occlusal plane of the record.

8- Adapt a newly mixed rope of laboratory putty (Poly V Putty; Accurate Set, Inc) along facial contours of neutral zone record to develop the facial index. Mold the putty so that it completely captures the facial contours of the neutral zone record. Once polymerized, remove both lingual and facial indices and ensure that they can be replaced securely on the cast, without the neutral zone record (Figs. 13A, 13B).

9- This neutral zone record will help the dental lab technician to arrange mandibular posterior denture teeth so that all posterior teeth contact the lingual index and all posterior occlusal surfaces are leveled with the planed occlusal plane.

8180

INTRODUCTIONIn chronic periapical lesions, the low intensity

chronic stimulus, provided by bacteria and their products, allows for the maintenance of inflammation in periapical region; the growth of these lesions results in bone resorption that is visible radiographically1. Apical inflammatory root resorption forms part of periapical pathology associated with apical periodontitis2.

Most endodontic lesions occur as a result of leakage of irritants from pathologically involved root canals into periradicular tissues. An adequate apical seal is a major factor that is indispensable for improving endodontic success3. Clinically, obturation of canals with extensive apical inflammatory root resorption is not an easy task. Conventional root canal filling techniques rely on the presence of a constriction at apical level of the canal; therefore, absence of apical constriction (because of incomplete root development), aggressive apical resorption, or iatrogenic enlargement are obviously clinical challenges. Placement of root filling in a canal with an open apical foramen carries the risk of root filling material extrusion, which may compromise the long-term outcome of treatment4. Mineral trioxide aggregate (MTA) has a profound advantage when used

as canal obturation material because of its superior physiochemical and bioactive properties5; MTA is a bioactive cement that is nonirritating to periapical tissues, it induces regeneration of bone, cementum, and periodontal ligament. Human osteoblasts show adhesion to the material, indicating favorable biologic responses and biocompatibility3, 5. When MTA comes in contact with physiological fluids in vivo, reactions take place between them and form a layer of hydroxyapatite between MTA and canal walls; this layer has been demonstrated to release calcium and phosphorous continuously. In addidtion, this phenomenon increases the sealing ability of MTA and promotes regeneration and remineralization of hard tissues. This hydroxyapatite layer also forms over the material and fills the voids and surface defects. Formation of this layer develops a chemical bond between MTA and dentinal walls that might be the key characteristic responsible for successful performance of this material6.

Several MTA formulations are marketed such as: ProRoot MTA (Dentsply-Tulsa Dental, Tulsa-USA), MTA Angelus (Angelus, Londrina, PR, Brazil), and MM-MTA™ (Micro-Mega, Besançon, France).

MM-MTA™ is a modified class of MTA developed to overcome the major drawbacks of MTA: slow setting time and difficult handling and manipulation. Like other MTA products, it is mainly composed of Portland cement but with a variation in the amount of

Obturation of root canals with varying degrees of apical inflammatory root resorption in a mandibular second molar: A case report.Carla Jabre1, Dr. Chir. Dent., MS (Endo.), Issam Khalil2, Dr. Chir. Dent., CES (Oral Biol.), CES (Conservative Dent./Endo.), MS (Oral Biol.), Dr. Univ.

AbstractApical inflammatory root resorption is common in chronic periapical periodontitis and causes a difficulty in

root canal obturation. This case reports the obturation of varying degrees of apical root resorption in a mandibular second molar, with gutta-percha and MM-MTA™, and the beginning of healing, 5 months later.

In cases of severe apical inflammatory root resorption due to chronic apical periodontitis, creating an apical plug with MTA may be an appropriate option to avoid overextension of obturation material.

1. Chargée de Stages Cliniques, Department of Endodontics, Saint-Joseph University, Faculty of Dental Medicine, Beirut, 2. Assistant Professor and Chairperson, Department of Endodontics, Saint-Joseph University, Faculty of Dental Medicine, Beirut

Endodontics

5. Tallgren A. The continuing reduction of the residual alveolar ridges in complete denture wearers: a mixed-longitudinal study covering 25 years. J Prosthet Dent 1972;27:120-132.6. Goumy R, Mokbel R., Triloff P. Variation de l’espace prothétique chez l’édenté complet. Le Chirurgien-Dentiste de France # 195, March 17, 1983. p.53-557. Beresin VE, Schiesser FJ. The neutral zone in complete dentures. J Prosthet Dent 1976;36:356-67.8. Massad JJ et al. Cameograms: A new technique for prosthodontic applications, Dentistry Today 2016 Mar;35(3):80,82,84-85.9. Daher T et al. Successful and Predictable Custom Made Complete Dentures. Dentistry Today 2016 Mar;35(3):86-89.10. Fish EW. Principles of full denture prosthesis. London: John Bale, Sons & Danielsson, Ltd; 11, 1933. p. 1-8.11. Weinberg LA. Tooth position in relation to the denture base foundation. J Prosthet Dent 1958;8:398-405.12. Wright CR, Swartz WH, Godwin WC. Mandibular denture stability - a new concept. Ann Arbor: The Overbeck Co; 1961. p. 29-41.13. Murray CG. Re-establishing natural tooth position in the edentulous environment. Aust Dent J 1978;23:415-21.14. Beresin VE, Schiesser FJ, editors. Neutral zone in complete and partial dentures. Mosby; 1978. 15. Desjardins RP. The tongue as it relates to complete dentures, J Am Dent Assoc 1974 Apr;88(4):814-82216. Fish EW. Using the muscles to stabilize the full lower denture. J Am Dent Assoc 1933;20:2163-2169.17. Matthews E. The polished surfaces. Br Dent J 1961;111:407-11.18. Wright SM. The polished surface contour: a new approach. Int J Prosthodont 1991;4:159-63.19. Brill N, Tryde G, Cantor R. The dynamic nature of the lower denture space. J Prosthet Dent 1965;15:401-418.20. Watt DM. Tooth positions on complete dentures. J Dent 1978;6:147-60.21. DeVan MM. The concept of neutrocentric occlusion as related to denture stability. J Am Dent Assoc 1954;48:165-169.22. Sharry JJ. Complete denture prosthodontics.3rd ed. New York: McGraw-Hill; 1974. p.241-265.23. Pound E. Esthetic dentures and their phonetic values. J Prosthet Dent 1951;1:98-111.24. Pound E, Murrell GA. An introduction to denture simplification. Phase II. J Prosthet Dent 1973;29:598-607.25. Halperin AR, Graser GN, Rogoff GS, Plekavich EJ. Mastering the art of complete dentures. Chicago: Quintessence; 1988. p. 12526. Lammie GA. Aging changes and the complete lower denture. J Prosthet Dent 1956;6:450-64.27. Heath R. A study of the morphology of the denture spaces. Dent Pract Dent Rec 1970 Dec;21(4):109-117. 28. Cagna DR, Massad JJ, Schiesser FJ, The neutral zone revisited, from historical concept to modern application, J Prosthet Dent 2009 Jun;101(6):405-412.29. Klein P. La Piézographie en prothèse adjointe mandibulaire. Thèse de Doctorat de 3ème cycle en Sciences Odontologiques. (Dr.Sc.Odont.) Paris, 1970.

30. Mokbel R. Etude comparative des différentes méthodes d’orientation du plan d’occlusion en prothèse adjointe. Thèse de Doctorat de 3ème cycle en Sciences Odontologiques. (Dr. Sc.Odont.), Paris, 1982.31. Mokbel, R. Technique Originale, Détermination du plan d’occlusion en Gérontologie. L’incisive, # 13, Oct 1982.p. 6-732. Rudd KD, Morrow RM. Baseplates and occlusion rims. In: Dental laboratory procedures: complete dentures, volume I. 2nd ed. Morrow RM, Rudd KD, Rhoads JE, editors. St. Louis: Mosby; 1986. p. 90-146.33. Rudd KD, Morrow RM, Feldmann EE, Espi- noza AV, Gorney C. Waxing and processing. In: Dental laboratory procedures: complete dentures, volume I. 2nd ed. Morrow RM, Rudd KD, Rhoads JE, editors. St. Louis: Mosby; 1986. p. 276-311 34. Boucher CO. Complete denture prosthodontics – The state of the art. J Prosthet Dent 1975;34:372-383.35. Fahmy FM, Kharat DU. A study of the importance of the neutral zone in complete dentures. J Prosthet Dent 1990 Oct;64(4):459-462.

Corresponding author:Robert [email protected]




plug procedures in teeth with necrotic pulps and open apices8,9,10,11.

Mente and co-workers4,12 also found that plugging open apical foramina with MTA yielded a predictable outcome compared with what can be expected in conventionally root filled teeth with undisturbed apical constriction. In the present case, distal canal had an apical diameter of 70 with an acceptable apical taper; a master cone of gutta-percha could be correctly placed and sealed, while in mesial canals, apical diameter and taper were not proper to avoid extrusion of gutta-percha.

The molded cone technique (that consists of taking the impression of the canal using a master cone of

gutta-percha after softening its surface with solvent), has been proposed for the obturation of large canals with open apices. However, in canals exhibiting open apices with a reverse apical architecture (like mesial canals in this case), this technique is not indicated due to the presence of undercuts13.

When filling a root canal with gutta-percha and sealer, there is a difference between overextension and overfilling: the first one is related to the extrusion of obturation material from a canal with internal under filling, due to a lack of deep shape or canal preparations exhibiting reverse apical architecture. The second one refers to the surplus after filling a three-dimensionally cleaned, shaped, and packed root. In cases of overfilling,

Fig. 1. Preoperative periapical radiograph showing a radiolucency and periapical resorption around both roots of tooth 47.

Fig. 2. Periapical radiograph showing the obturation of distal canal with gutta-percha and sealer and the MM-MTA™ apical plug in mesial root.

Fig. 3. Periapical radiograph showing complete obturation of root canals. Distal canal is obturated with gutta-percha and sealer. Mesial root is obturated with an apical plug of MM-MTA™ and with gutta-percha and sealer in the coronal thirds.

Fig. 4. Periapical radiograph showing the healing of radiolucencies on both roots, 5 months after obturation.

gypsum and radiopaque component, and the addition of calcium carbonate and a novel presentation in predosed capsules triturated mechanically instead of being hand mixed; these modifications allow the cement to have a faster setting time, an easier manipulation, and a reproducible and extremely homogenous consistency7.

This case report describes the use of MM-MTA™ as an apical plug in a mandibular molar with different degrees of apical inflammatory root resorption before filling canals with gutta-percha.

CASE REPORTA 34-year-old male was referred to the Endodontic

Department of the Faculty of Dental Medicine, at Saint-Joseph University, Beirut, Lebanon, for root canal treatment on mandibular right second molar. Patient reported that treatment was initiated almost a year ago in a private clinic, but the canals were not obturated. The tooth was asymptomatic.

Radiographic examination revealed radiolucencies around apices of the tooth and an apical resorption, especially on mesial root (Fig. 1).

The tooth was diagnosed with chronic apical periodontitis, and the decision to treat it endodontically was made.

After the analgesia of right inferior alveolar nerve (Mepivacaine 3%, Epinephrine 1/100 000), dental rubber dam was placed (Clamp 12A-Hygenic ©). Access cavity was rectified using the Endo Z burr (Dentsply) to obtain straight access to canals.

After scouting the canals with a #10 K file, working lengths of distal (16mm), mesio-lingual (18mm), and mesio-buccal (16mm) canals were determined using K-flexofiles, verified with the apex locator (Root ZX Mini) and periapical radiographs.

Root canals were prepared with the "crown-down" (CD) technique that emphasizes cleaning and shaping the coronal third first, the middle third second, and apical third last (Marshall and Pappin, 1980). The distal canal was shaped with NiTi rotary files (ProTaper Universal System: S1-S2-F1-F2-F3 until working length).

Mesial canals, that joined apically, were manually shaped using K-Flexofiles® (Dentsply, Maillefer) and Gates-Glidden drills (Maillefer), in order to enlarge the canals coronally to permit the pluggers’ access to them.

Copious irrigation between each instrument was performed using 2.5% sodium hypochloride and patency was maintained using a #15 K-Flexofile®.

After cleaning and shaping, canals were dried with absorbent paper points but were still not completely dry from pus. A temporary coronal seal using Cavit© (3M ESPE AG, Seefeld, Germany) was carried out and the obturation was scheduled a week later. No intracanal medication was used between appointments.

At second appointment, recapitulation and copious irrigation were performed. Absence of pus was verified after completely drying the canals.

Distal canal had an apical diameter of 70 (verified with Nitiflex files). It was obturated with a fine-medium gutta-percha cone, placed 1mm from the foramen, and a sealer (Sealite®), using the warm vertical condensation technique.

Mesial canals had an apical diameter of 120. The apical part of these canals was obturated with a 5 mm plug of MM-MTA™: the MM-MTA™ cap was mechanically triturated for 30 seconds to mix the powder with the liquid. Then, using the MM-MTA™ gun, the content of the cap was placed on a glass plate, and small amounts of the cement were placed at the root canal orifice using a spatula. Then, using hand pluggers in a decreasing order, the cement was condensed apically to obtain an apical plug of 5mm thickness. Correct placement of MM-MTA™ was confirmed radiographically (Fig. 2).

Middle and coronal thirds of mesial canals were filled with gutta-percha and sealer (Sealite®) using the thermomechanical condensation technique with a gutta condenser of a size 50 (Fig. 3).

RESULTSA 5 months recall periapical radiograph shows a

reduction in the size of bone radiolucency around both distal and mesial roots. The healing of the lesion is in progress (Fig. 4).

Clinically, tooth was asymptomatic and patient did not report any pain or swelling, and percussion test was negative.

DISCUSSIONThe outcome in this clinical case is similar to

previously reported cases of successful MTA apical


CONCLUSIONThe present case report describes the endodontic

management of a mandibular second molar with varying degrees of apical inflammatory root resorption. The good outcome of this case reflects the importance of an apical plug with MM-MTA™ in canals with open foramina and negative apical architecture, whereas large canals where a continuous taper is possible after cleaning and shaping can be successfully sealed with gutta-percha.

REFERENCES1. Vier FV, Figueiredo JAP. Prevalence of different periapical lesions associated with human teeth and their correlation with the presence and extension of apical external root resorption. Int Endod J 2002;35:710 -719.2. Laux M, Abbott PV, Pajarola G, Nair PNR. Apical inflammatory root resorption: a correlative radiographic and histological assessment. Int Endod J 2000;33:483-493.3. Torabinejad M, Parirokh M. Mineral Trioxide Aggregate: A Comprehensive Literature Review—Part II: Leakage and Biocompatibility Investigations. J Endod 2010;36:190-202. 4. Mente J, Hage N, Pfefferle T, Koch MJ, Dreyhaupt J, Staehle HJ, Friedman S. Mineral Trioxide Aggregate Apical Plugs in Teeth with Open Apical Foramina: A Retrospective Analysis of Treatment Outcome. J Endod 2009;35:1354-1358. 5. Bogen G, Kuttler S. Mineral Trioxide Aggregate Obturation: A Review and Case Series. J Endod 2009;35:777-790. 6. Parirokh M, Torabinejad M. Mineral Trioxide Aggregate: A Comprehensive Literature Review—Part III: Clinical Applications, Drawbacks, and Mechanism of Action. J Endod 2010;36:400-413. 7. Khalil IT, Sarkis T, Naaman A. MM-MTA for direct pulp capping: A histologic comparison with ProRoot MTA in rat molars. J Contemp Dent Pract 2013;14(6):1019-1023. 8. Shabahang S, Torabinejad M. Treatment of teeth with open apices using mineral trioxide aggregate. Pract Perio Aesthet Dent 2000;12(3):315-320. 9. Giuliani V, Baccetti T, Pace R, Pagavino G. The use of MTA in teeth with necrotic pulps and open apices. Dent Traumatol 2002;18(4):217-221. 10. Maroto M, Barbería E, Planells P, Vera V. Treatment of a non-vital immature incisor with mineral trioxide aggregate (MTA). Dent Traumatol 2003;19(3):165-169. 11. Pace R, Giuliani V, Nieri M, Di Nasso L, Pagavino G. Mineral trioxide aggregate as apical plug in teeth with necrotic pulp and immature apices: a 10-year case series. J Endod 2014;40(8):1250-1254. 12. Mente J, Leo M, Panagidis D, Ohle M, Schneider S, Bermejo JL, Pfefferle T. Treatment Outcome of Mineral Trioxide Aggregate in Open Apex Teeth. J Endod 2013;39:20-26. 13. Maestroni F. Chapter 23: “La technique du cône moulé » in Laurichesse JM, Maestroni F, Breillat J Endodontie Clinique. Editions CDP, Paris, 1986.

14. Ruddle CJ. Endodontic overfills: Good? Bad? Ugly?. Dentistry Today 1997 May;16(5):62-65. 15. Pertot WJ, Simon S. Chapter 5: «Obturation du système canalaire» in Pertott WJ, Simon S. Le traitement endodontique. Quintessence International, 2004. 16. Parirokh M, Torabinejad M. Mineral Trioxide Aggregate: A Comprehensive Literature Review—Part I: Chemical, Physical, and Antibacterial Properties. J Endod 2010;36:16-27.17. Khalil I, Naaman A, Camilleri J. Investigation of a novel mechanically mixed Mineral Trioxide Aggregate (MM-MTA™). Int Endod J 2015 Aug;48(8):757-767. 18. Khalil I, Isaac J, Chaccar C, Sautier JM, Berdal A, Naaman N, Naaman A. Biocompatibility assessment of modified Portland cement in comparison with MTA®: in vivo and in vitro studies. Saudi Endod J 2012;2(1):6-13. 19. Felippe WT, Felippe MCS, Rocha MJC. The effect of mineral trioxide aggregate on the apexification and periapical healing of teeth with incomplete root formation. Int Endod J 2006;39:2-9.20. Mohammadi Z, Dummer PM. Properties and applications of calcium hydroxide in endodontics and dental traumatology. Int Endod J 2011;44:697-730.21. Peters LB, Van Winkelhoff AJ, Buijs JF, Wesselink PR. Effects of instrumentation, irrigation and dressing with calcium hydroxide on infection in pulpless teeth with periapical bone lesions. Int Endod J 2002;35:13-21. 22. Johnson WT, Kulild JC. Chapter 10: “Obturation of the cleaned and shaped root canal system”, in Hargreaves K, Cohen S, Pathways of the pulp tenth edition, Mosby Elsevier, 2011. 23. Shokouhinejad N, Nekoofar MH, Iravani A, Kharrazifard MJ, Dummer PM. Effect of acidic environment on the push-out bond strength of mineral trioxide aggregate. J Endod 2010;36(5)871-874. 24. Shokouhinejad N, Yazdi KA, Nekoofar MH, Matmir S, Khoshkhounejad M. Effect of Acidic Environment on Dislocation Resistance of Endosequence Root Repair Material and Mineral Trioxide Aggregate. Journal of Dentistry (Tehran) 2014;11(2):161-166. 25. American Association of Endodontics. Glossary of Endodontic Terms, Eigth edition, 2012.

Corresponding author:Issam [email protected]

MM-MTA™ (Micro-Mega®) is an endodontic repair cement developed by Professors Issam Khalil and Alfred Naaman at the Saint-Joseph University laboratories, in Beirut, Lebanon. Both doctors hold the WIPO patent for MM-MTA™, a product manufactured by Scpolymere, Germany, and distributed by Micro-Mega, France.

it is now well understood that these amounts of sealer and/or gutta-percha in the attachment apparatus do not cause the failure of endodontic treatment14,15. This explains the healing of bony lesion around distal root (where an overfilling can be noticed).

In the study conducted by Mente and co-workers4, extrusion of MTA® did not affect healing rate. This lack of adverse effects, which could be attributed to the good tissue compatibility of MTA®, makes it the cement of choice for root canals with wide apical foramina.

The difficult handling and the very long setting time of ProRoot MTA® have been viewed as two of the major drawbacks of the material16. MM-MTA™ is composed primarily of Portland cement and bismuth oxide such as other MTA® products. However, it has certain advantages over other MTA® products that made it the cement of choice in this case: first of all, it contains calcium carbonate and a chloride accelerator. These additives result in a shorter setting time (20 minutes) for MM-MTA™(17), which allowed for the completion of the obturation in one session. Second of all, MM-MTA™ is presented in capsule form that is mechanically triturated; thus, it facilitates the mixing procedure when compared to other MTA® products17; it allows clinicians to get a stable composition and fluidity instead of hand mixing powder and liquid7. Third of all, the addition of calcium carbonate enhances viscosity of the material and gives it a putty consistency which offers an ability to manipulate more easily without the possibility of displacement of the cement when it is condensed7. In terms of biocompatibility, MM-MTA™ had been proven to be similar to MTA®: both showed no or very limited toxic effects in vitro and similar biocompatibility in vivo18.

The use of calcium hydroxide as an intracanal medication remains controversial: it has been demonstrated that regardless of whether calcium hydroxide paste was used or not as an intracanal medication for 1 week before the MTA® apical plug, apical repair and barrier formation occurred in 100% of the teeth with necrotic pulps and immature apices in dogs19. Weiger and co-workers (2000) evaluated the influence of calcium hydroxide as an interappointment dressing on the healing of periapical lesions associated with pulpless teeth. In both treatment groups, the likelihood that the root canal treatment yielded a

success within an observation time of 5 years exceeded 90%. However, a statistically significant difference between the two treatment groups was not detected. Similar results were obtained by Peters & Wesselink (2002) and Molander and associates (2007)20. Peters and co-workers21 found that calcium hydroxide limits but does not totally prevent regrowth of endodontic bacteria when used as an intracanal mediaction between appointments. These studies suggest that the use of calcium hydroxide in such cases may not increase healing’s chances. In addition, it has been demonstrated that complete removal of calcium hydroxide paste from root canal walls is not achievable with routine techniques. Laboratory studies have revealed that remnants of calcium hydroxide can hinder the penetration of sealers into the dentinal tubules (Calt & Serper, 1999), increase apical leakage of root fillings (Kim & Kim, 2002), and potentially interact with zinc oxide eugenol sealers and make them brittle and granular (Margelos et al., 1997)20. These disadvantages of calcium hydroxide push in favor of not using it as an intracanal medication.

In general, obturation with gutta-percha can be performed after cleaning and shaping procedures when the canal can be dried and the patient is not experiencing swelling. An exception is the presence or persistence of exudation from the canal. Obturation of a canal that cannot be dried is contraindicated22. MTA® has been found to reduce surface microhardness, decrease sealing ability, and decrease push out bond strength when it is in contact with an acidic environment23,24. For this reason, obturation of mesial and distal canals (of the present case report) was not done at the first appointment but scheduled a week later because at that time, all the canals were completely dry from pus.

The recall, 5 months after the end of treatment, showed that periapical bone radiolucencies (around both roots) have almost completely disappeared. Clinically, there was no pain, swelling, sinus tract, or tenderness to apical and gingival palpation or percussion. According to the AAE Endodontic Glossary25, this case could be considered healed: “functional, asymptomatic teeth with no or minimal radiographic periradicular (apical) pathosis (radiolucency)25.”



might include root resection or hemisection. Root hemisection, which aims to retain as much of

the original tooth structure as possible (Kost & Stakiw, 1991), entails the surgical separation of a multi-rooted tooth through the furcation in a way that root and overlying anatomic crown may be removed (American Academy of Periodontology, 2001).

Some options for restoring this type of tooth include restoring the remaining root as an individual tooth; restoring individual roots with either a molar or premolar morphology by using the adjacent tooth as an abutment in a full coverage fixed partial denture; or restoring individual roots with either molar or premolar morphology using an inlay type of restoration on adjacent abutment tooth.

Appropriate endodontic therapy must be performed before modifying the tooth in order to avoid postoperative tooth sensitivity (Rapoport & Deep, 2003), followed by carefully smoothing the furcation region to allow proper cleaning, and thus, prevent plaque accumulation.

Indications for root resection or hemisection can be divided into three categories: periodontal, endodontic, and restorative. These categories include root fracture or perforation, external root resorption, and a severe destructive process as a result of subgingival caries, making adequate restoration non-viable (DeSantis & Murphy, 2000 - Weine, 2003).

Long-term successful outcomes with absence of pathosis after a root resective treatment depends on several factors including case selection (Saad et al., 2009), surgical performance, periodontal disease, endodontic treatment, oral hygiene as well as a highly motivated patient (Livada et al., 2014).

Failures in resected mandibular molars have been due mainly to biomechanical elements and root fractures (Langer et al., 1981 - Svärdström & Wennström, 2000), thus adaptation of modified tooth surface to a normal occlusion free of occlusal interferences must be mandatory to balance occlusal forces (Saad et al., 2009).

The aim of this case report is to present a clinical approach of a decayed mandibular molar treated with root canal treatment and a hemisection of the distal root.

CASE REPORTIn April 2009, a 38-year-old male patient with

a noncontributory medical history, complaining of intermittent pain on mandibular left side of his mouth, was referred by the Oral Surgery Department to the Department of Endodontics at the Universitat Internacional de Catalunya in order to evaluate the options for preserving mandibular left first molar (Fig. 1).

Cold vitality test triggered intense but short-lasting pain, which led us to diagnose a symptomatic reversible pulpitis. Radiographic examination revealed distal bone loss and second molar impaction (Figs. 2,3).

We decided that, instead of extracting tooth 36, we would rather try to partially preserve it by intentional root canal treatment, hemisection with removal of its distal half followed by restoration and orthodontic repositioning of the first, second and third mandibular molars. The patient consented to our proposed treatment planning after being fully informed about the methods and treatment risks.

After local analgesia and rubber dam isolation (Hygenic Dental Dam, ColténeWhaledent, Langenau, Germany), an endodontic access cavity was prepared with round diamond burs and Endo-Z burs (Dentsply Maillefer, Ballaigues, Switzerland) with a water-cooled, high-speed handpiece. Removal of pulp chamber roof with a round carbide bur revealed three canal orifices. Root lengths were estimated with an apex locator (Root ZX; Morita, Tokyo, Japan) and then confirmed with a periapical radiograph (Fig. 4a). All canals were instrumented with a size 10 and 15 K-file (Zipperer, Munich, Germany) to obtain a manual glide path. Instrumentation was completed using Mtwo (VDW GmbH, Munich, Germany) nickel–titanium (NiTi) rotary files with an Endo-Mate torque control endodontic motor (NSK, Europe, Frankfurt, Germany). Instrumentation sequence for the three canals was 10.04; 15.05; 20.06; 25.06; 30.05; and 35.04 to the working length. During instrumentation, root canals were flushed with copious amounts of 4.2% sodium hypochlorite solution using a plastic syringe with a closed-end needle (Hawe Max-I-probe; Kerr-Hawe, Bioggio, Switzerland).

After root canal preparation, a final irrigation was performed with 1 ml of 10% citric acid for 1 minute and with 4.2% sodium hypochlorite. The last sodium hypochlorite solution was activated with a size 15 K-file (Satelec Acteon Group) under passive ultrasonic

INTRODUCTIONOne of the principle objectives of endodontics and

periodontics is to prevent infection by eliminating bacteria. Treatment options for a molar with extensive decay may only include a fixed or removable partial denture or a dental endosseous osseointegratable implant to replace the missing tooth. Alternatively, a root resection procedure may be possible if the decay is confined to one root. Therefore, periodontal, prosthodontic, and endodontic assessments for the appropriate selection of cases are of utmost importance.

According to the American Association of Orthodontists (American Association of Orthodontists, 2012), tooth impaction refers to a condition that describes a failure of a tooth to emerge on dental arch after the normal age for eruption. Impaction of mandibular second permanent molars has an incidence of 0.03% in general population (Grover & Norton, 1985). It results in an impediment to a functional occlusion (Raghoebar et al., 1991) and often leads to difficulty in maintaining a proper interproximal hygiene. This condition fosters a severe destructive process as a result of subgingival caries that may even affect root surface. This is obviously a challenge for the clinician because tooth restoration can be laborious or ineffectual if the extension of decayed lesion makes teeth unsuitable for restoration. Treatment options in unrestorable molars include an implantological or prosthetic approach to replace the missing tooth. However, if only one root is affected, it could be appropriate to take a more conservative approach that

Root canal treatment and hemisection of a decayed mandibular molar as a treatment option: A five-year follow-up case report.Marc García Font1, DDS, Dr. Odontologia,Juan Gonzalo Olivieri2, DDS, Dr. Odontologia, Francesc Abella3, DDS, Dr. Odontologia, Jordi Ortega4, DDS, Akram Hussein Ali5, DDS, Dr. Odontologia, Miguel Roig Cayón6, DDS, Dr. Odontologia, Fernando Durán-Sindreu7, DDS, Dr. Odontologia

AbstractAim: To address a successful conservative treatment of a mandibular molar treated with root canal treatment and

hemisection of distal root. This case report describes a clinical approach of a decayed mandibular first molar treated with root canal therapy

and hemisection of distal root, and posterior uprighting of second and third mandibular molars. At 5-year follow-up examination, clinical and radiographic findings showed a complete healing and absence of bone loss. Patient remained asymptomatic over this five-year period.

Conclusive learning points:- A molar with extensive decay that may be unsuitable for restoration is a challenge for dentists.- Treatment options in non-restorable molars include an implantological or prosthetic approach to replace the

missing tooth. However, if only one root is affected, it may be appropriate to take a more conservative approach that might include root canal treatment and root hemisection, which aims to retain as much of the original tooth structure as possible.

1. Associate Professor2. Associate Professor3. Associate Professor4. Associate Professor5. Associate Professor6. Associate Professor and Department Chairperson7. Professor and Director of Masters of Endodontics Program, 1 to 7. Department of Endodontics, Universitat Internacional de Catalunya - UIC, Facultad de Odontología, Barcelona, Spain.

Conservative Dentistry



success rate over an eleven-year observation period after root resection, and Carnevale and co-workers6 reported an approximate success rate of 95% in a retrospective study on 185 resected molars over a seven to ten-year observation period.

These disparate results highlight the importance of clinical procedure and demonstrate that root resection requires dexterity and high surgical skills.

When aiming for a better prognosis, adequate case selection is essential, especially when planning a suitable treatment for compromised teeth. To this

end, one factor that must be taken into account is the relationship between bone support of remaining roots at the time of resection and their survival rate. Remaining root with a bone support of more than 50% has a significantly increased survival rate (Park et al., 2009), although a critical level of bone support has not been identified. While same authors reported an increased failure rate because of a nonperiodontal problem (such as dental caries), their data on resection failure did not discriminate between maxilla or mandibular molars.

In the present reported clinical case, distal root

Fig. 1. Clinical situation at baseline. Fig. 3. A preoperative panoramic radiograph gives a general view of mandibular molars.

Fig. 4. (a) A working length periapical radiograph. (b) Gutta-percha cones before root canal filling. (c) Postoperative radiograph.

Fig. 5. Vertical cut towards bifurcation area.

Fig. 6. Clinical image after hemisection and extraction of distal root.

Fig. 7. Clinical image showing vertical bone loss around distal root.

Fig. 9. (a) Radiograph showing retained mesial portion after hemisection procedure. (b) Recall radiograph, five-year after root canal treatment and hemisection. (No further bone loss was observed).

Fig. 8. Distal root of tooth 36 after extraction.

Fig. 2. A preoperative periapical radiograph of the tooth revealing distal bone loss and second molar impaction.

activation for 1 minute. Root canals were then dried with sterile paper points. After preparation, gutta-percha cones (Autofit; Analytic, Glendora, California, USA) were used to reconfirm working lengths (Fig. 4b). Root canals were obturated with warm vertical condensation for the apical third followed by backfill with injected gutta-percha using the Elements™ Obturation Unit (Sybron Endo; Glendora, CA). AH-Plus® cement (Dentsply DeTrey GmbH, Konstanz, Germany) was used as root canal sealer. Postoperative radiograph revealed a successful obturation (Fig. 4c). Access cavity was restored with a resin composite during the same visit (Tetric; Ivoclar Vivadent AG, Schaan Furstentum, Liechtenstein).

At the following appointment, root resection procedure was completed. Under local analgesia, a full thickness (mucoperiostal) flap was raised to expose bony crest, in preparation to hemisection procedure. Distal root and distal half of the anatomic crown were sectioned with a diamond bur, at furcation level (Fig. 5), and a fine probe was passed through the cut to ensure full separation. After carefully removing the distal half (Fig. 8) with elevators (Fig. 7), we prepared the mesial half as a premolar (Fig. 6), irrigated the surgical area with 0.12% Chlorhexidine, repositioned and sutured the flap with 4/0 black silk sutures, and finally smoothed distal area of mesial root and its coronal portion using a finishing diamond bur (Fig. 9a).

Sutures were removed ten days after root resection, showing that soft tissues appeared to be healing well and the mesial root remained asymptomatic. Tooth 36 had grade I-II mobility and 2–3 mm probing depth. After complete healing of tissues, the mesial half of the molar was restored with an indirect resin-bonded overlay performed with Adoro® (Ivoclar Vivadent AG, Schaan Furstentum, Liechtenstein) with a premolar anatomical shape.

The patient was referred to the University Clinic Orthodontic Department for uprighting second and third mandibular molars into their correct positions, and after orthodontic treatment, patient presented to the Endodontic Department for post-operative follow-ups where mobility and probing were checked.

At 5-year clinical/radiological follow-up, tooth 36 had 2-3 mm probing depths and no mobility. No further bone loss was observed in radiographs (Fig. 9b) and patient experienced neither pain nor discomfort over this five-year post-operative period.

DISCUSSIONTooth impaction is usually due either to space

deficiencies or presence of an entity blocking its eruption path. In this case, it appeared to be the result of a lack of space in the arch, which is a common cause of teeth impaction (Shafer et al., 1983), especially in second molars (Johnson & Quirk, 1987). Consequences include occlusal disorders and accumulation of food remnants between impacted tooth and adjacent tooth, preventing proper oral hygiene and predisposing interproximal surfaces to dental caries that, in some cases, result in a destructive process, making restoration unviable.

Root amputation and hemisection should be considered as an alternative to extraction in order to retain natural dentition. In this case report, we described a severe destructive process as a result of subgingival distal caries, which has been listed as a restorative indication for root resection (Weine, 2003). Hemisected tooth procedure is recognized as a conservative and reliable treatment option (Parmar & Vashi, 2003) that calls for highly aesthetic and functional outcomes.

Several parameters should be considered when choosing a tooth retention treatment planning, including the amount of supporting tissue and root mobility (Hamp et al., 1975). In the present case, the patient’s wish to retain his tooth was a major factor in the treatment planning.

Treatment success, defined as retention in absence of pathosis, has been reported to be determined by several factors, such us case selection, surgical and endodontic procedures, restoration, and an adequate occlusion. However, patient oral hygiene is a key factor to a successful outcome. Thus, patient should be able and motivated to make an extra effort to minimize plaque accumulation.

There is no consensus on the long-term outcome of root resection. According to the observations of a retrospective study conducted by Langer and associates16, who reported a 38% failure rate in 100 resected molars, most failures occurred between five and ten years after treatment. These results are in agreement with the results of various studies (Park et al., 2009 - Blomlöf et al., 1997 - Fugazzotto, 2001), although Blomlöf and co-workers5 reported an 11% failure rate at five years, and a 32% at 10 years. Dannewitz and associates7, on the other hand, observed a 42% failure rate at nine years. However, Bergenholtz4, in a long-term study on resected molar survival, reported a 85%

9190

INTRODUCTIONSubmental fullness is a condition that affects

populations, worldwide. It usually results from aging as the submandibular skin loses its form and consistence, but it may also be due to a genetic predisposition or to a poor diet.

In 2014, a survey showed that 68% of Americans were unhappy with unwanted fat underneath their chin. They were troubled about this appearance that proved to be one of the most frequent personal appearance complaints.

Kybella® is a cosmetic injection treatment designed for a cosmetic improvement of submental region.

On April 2015, Kybella® (deoxycholic acid) was approved by the FDA to use for the reduction of moderate-to-severe supraplatysmal submental fat. Kybella has been extensively studied5 to 15. Two early phase 3 clinical trials showed impressive results: two European randomized, double-blind, placebo-controlled clinical studies (NCT010305577 and NCT01294644) demonstrated that an ATX- 101 (Kybella®) injection into the submental fat was superior to placebo in terms of the Clinician-Reported (CR) Submental Fat (SMF)

Rating Scale (CR-SMFRS), Patient-Reported (PR) SMF Rating Scale (PR-SMFRS), and reduction of submental fat as confirmed by caliper measurement5,6,7. The SMF rating scale was a study specific grading scale that ranged from 0 (no localized SMF) to 4 (extreme submental convexity). Specifically, a greater than 1-point improvement in CR-SMFRS was seen in 59% of patients receiving 1 mg/cm² of ATX-101, and 64% of patients receiving 2 mg/cm² of ATX-101, compared to 29% of patients receiving placebo. Some of the adverse events11 were minor and included: injection site pain, swelling, bruising, numbness, erythema, induration, and injury to the marginal mandibular branch of the facial nerve (only 2%). These side-effects resolved within 4 weeks after injection. In North America, The REFINE-1 and REFINE-2 (Randomized Double-blind Evaluation of Submental Fat Reduction in ATX-101 treated patients) included 1019 patients who received 0.2 mg/cm², with 0.2 ml per injection site spaced 1 cm apart from the next injection site8.

As with any cosmetic procedure, patient selection is most important. Kybella® is indicated for isolated supraplatysmal submental fat deposits without skin excess. In fact, younger patients with minimal to moderate submental fat deposits are ideal candidates for Kybella® treatment.

KYBELLA® INJECTION TREATMENTWhen injected into submental fat, deoxycholic acid

helps destroying fat cells (FDA, 2015). This treatment

Deoxycholic acid injection for the reduction of submental fat in adults: An alternative to chin liposuction.Elie M. Ferneini1, DMD, MD, MHS, MBA, ABOMFS, FACS, Fellow of Pierre Fauchard AcademyMohammad Banki2, DMD, MD, FACS

AbstractSubmental fat1,2,3 remains a major problem in maxillofacial surgery patients. Until the middle of 2015, the only

treatment modality for these patients was submental liposuction. On April 29, 2015, Kybella® (deoxycholic acid, also known as cholanoicacid) was approved by the FDA* for the reduction of moderate-to-severe submental fat in adult patients. This product is actually identical to the deoxycholic acid that is produced in our body to help absorb fat. It is a cytolytic drug, which, when injected into tissue, physically destroys cell membrane causing lysis4. Kybella® destroys fat cells, when injected into submental fat; It is a reasonable, non-surgical, injectable alternative to chin liposuction.

1. Assistant Clinical Professor, Division of Oral and Maxillofacial Surgery, University of Connecticut School of Dental Medicine, Farmington, Connecticut, USA,Editor-in-Chief, American Journal of Cosmetic Surgery,2. Clinical Professor, Division of Oral and Maxillofacial Surgery, University of Connecticut School of Dental Medicine, Farmington, Connecticut, USA*FDA = Food and Drug Administration of the USA.

Facial Esthetic and Anti-Aging Medicine

was resected because the location of the decay did not allow a correct restoration. Biological width is essential to preserve periodontal health and avoid damage to the periodontum (Babitha et al., 2012).

A non-polished surface after hemisection can cause localized irritation to periodontum, giving rise to periodontal infections, an increase of periodontal attachment loss, and associated inflammation. Furthermore, overhangs increase plaque formation (Keszthely & Szabo, 1984) and change periodontal disease flora (Lang et al., 1983). Thus, in the follow-up appointment, we repolished the distal surface.

CONCLUSIONRoot canal treatment and distal root hemisection,

due to an extensive decay process, may be a suitable alternative treatment option to extraction and implant therapy, even in complex cases where a multidisciplinary approach can help enabling tooth maintenance with a good long-term prognosis.

REFERENCES1. American Association of Orthodontists (2012) Glossary of Terms: American Association of Orthodontists.2. American Academy of Periodontology (2001) Glossary of Periodontal Terms, 4th edn. Chicago, USA. American Academy of Periodontology pp. 45.3. Babitha Nugala, BB Santosh Kumar, S Sahitya, P Mohana Krishna. Biologic width and its importance in periodontal and restorative dentistry. J Conserv Dent 2012;15:12-17.4. Bergenholtz A. Radectomy of multirooted teeth. J Am Dent Assoc 1982;85:870-875. 5. Blomlöf L, Jansson L, Appelgren R, Ehnevid H, Lindskog S. Prognosis and mortality of root-resected molars. Int J Periodontics Rest Dent 1997;17:190-201.6. Carnevale G, Pontoriero R, di Febo G. Long-term effects of root-resective therapy in furcation-involved molars. A 10-year longitudinal study. J Clin Periodontol 1998;25:209-214.7. Dannewitz B, Krieger JK, Husing J, Eickholz P. Loss of molars in periodontally treated patients: a retrospective analysis five years or more after active periodontal treatment. J Clin Periodontol 2006;33:53-61.8. DeSanctis M, Murphy KG. The role of resective periodontal surgery in the treatment of furcation defects. Periodontology 2000, 2000 Feb;22:154-168. 9. Fugazzotto PA. A comparison of the success of root resected molars and molar position implants in function in a private practice: results of up to 15-plus years. J Periodontol 2001;72:1113-1123.10. Grover PS, Norton L. The incidence of unerupted permanent teeth and related clinical cases. Oral Surg, Oral Med Oral Pathol 1985;59:420-425.

11. Hamp SE, Nyman S, Lindhe J. Periodontal treatment of multirooted teeth. Results after 5 years. J Clin Periodontol 1975;2:126-135.12. Johnson JV, Quirk GP. Surgical repositioning of impacted mandibular second molar teeth. Am J Orthod Dentofacial Orthop 1987 Mar;91:242-251.13. Keszthelyi G, Szabo I. Influence of Class II amalgam fillings on attachment loss. J Clin Periodontol 1984;11:81-86. 14. Kost WJ, Stakiw JE (1991) Root amputation and hemisection. J Can Dent Assoc 1991 Jan;57(1):42-45.15. Lang NP, Kiel RA, Anderhalden K. Clinical and microbiological effects of subgingival restorations with overhanging or clinically perfect margins. J Clin Periodontol 1983 Nov;10(6):563-578.16. Langer B, Stein SD, Wagenberg B. An evaluation of root resections. A ten-year study. J Periodontol 1981 Dec;52(12):719-722. 17. Livada R, Fine N, Shiloah J. Root amputation: a new look into an old procedure. New York State Dent J 2014;80:24-28. 18. Park SY, Shin SY, Yang SM, Kye SB. Factors influencing the outcome of root-resection therapy in molars: a 10-year retrospective study. J Periodontol 2009;80:32-40.19. Parmar G, Vashi P. Hemisection: A Case Report and Review. Endodontology 2003;15:26-29.20. Raghoebar GM, Boering G, Vissink A. Clinical, radiographic and histological characteristics of secondary retention of permanent molars. J Dent 1991;19:164-170.21. Rapoport RH, Deep P. Traumatic hemisection and restoration of a maxillary first premolar: a case report. General Dent 2003;51:340-342. 22. Saad MN, Moreno J, Crawford C. Hemisection as an alternative treatment for decayed multirooted terminal abutment: a case report. J Can Dent Assoc 2009;75:387-390.23. Shafer WG, Hine MK, Levy BM (1983) A textbook of Oral Pathology 4th edn Philadelphia, PA, USA: WB Saunders Co.24. Svärdström G, Wennström JL. Periodontal treatment decisions for molars: an analysis of influencing factors and long-term outcome. J Periodontol 2000;71:579-585.25. Weine FS. Endodontic Therapy, 6th ed: Mosby Publications, 2003.

Corresponding author:Marc García [email protected]




indicated for the improvement in the appearance of moderate to severe fullness associated with submental fat in adults ("double chin"). The most common side-effects10 (>20% of patients) include erythema, induration, bruising, edema/swelling, hematoma, pain and numbness. Serious side-effects10,11 include swallowing troubles and facial nerve injuries (that may induce an uneven smile or platysma muscle weakness).

Kybella® treatment is a minimally invasive approach to submental fat contouring which has proven patient- and clinician-validated clinical efficacy5,6,7,8,10 to 15, as well as an acceptable safety profile. Knowledge of submental region anatomy1, patient selection, and reduction of adverse events will allow us to achieve optimal outcomes and patient satisfaction.

REFERENCES1. Pilsl U, Anderhuber F. The chin and adjacent fat compartments. Dermatol Surg 2010 Feb;36(2):214-2182. Illouz YG. The origins of lipolysis. Hetter GP, ed. Lipoplasty: The Theory and Practice of Blunt Suction Lipectomy. New York: Lippincott Williams & Wilkins, 1984. 3. Hetter GP. Lipoplasty of the face and neck. Lipoplasty: The Theory and Practice of Blunt Suction Lipectomy. New York: Lippincott Williams & Wilkins, 1984.4. FDA News Release: FDA approves treatment for fat below the chin. http://www.fda.gov/NewsEvents/Newsroom/Press Announcements/ucm444978.htm. Accessed January 21, 2016.5. Ascher B, Hoffmann K, Walker P, Lippert S, Wollina U, Havlickova B. Efficacy, patient-reported outcomes and safety profile of ATX-101 (deoxycholic acid), an injectable drug for the reduction of unwanted submental fat: results from a phase III, randomized, placebo-controlled study. J Eur Acad Dermatol Venereol 2014;28(12):1707-1715. 6. McDiarmid J, Ruiz JB, Lee D, Lippert S, Hartisch C, Havlickova B. Results from a pooled analysis of two European, randomized, placebo-controlled, phase 3 studies of ATX-101 for the pharmacologic reduction of excess submental fat. Aesthetic Plast Surg 2014;38(5):849-860.7. Rzany B, Griffiths T, Walker P, Lippert S, McDiarmid J, Havlickova B. Reduction of unwanted submental fat with ATX-101 (deoxycholic acid), an adipocytolytic injectable treatment: results from a phase III, randomized, placebo-controlled study. Br J Dermatol 2014;170(2):445-453.8. Dayan SH, Jones DH, Carruthers J, et al. A pooled analysis of the safety and efficacy results of the multicenter, double-blind, randomized, placebo-controlled phase 3 REFINE-1 and REFINE-2 trials of ATX-101, a submental contouring injectable drug for the reduction of submental fat. Plast Reconstr Surg 2014;134(4S-1):123.9. Kythera. Kybella: Product Insert. 2015.

10. Dover JS, Kenkel JM, Carruthers A, et al. Management of patient experience with ATX-101 (Deoxycholic acid injection) for reduction of submental fat. Dermatol Surg 2016 Nov;42(Suppl 1): S288-S299.11. Fagien S, McChesney P, Subramanian M, Jones DH. Prevention and management of injection-related adverse effects in facial aesthetics: considerations for ATX-101 (Deoxycholic acid injection) treatment. Dermatol Surg 2016 Nov;42(Suppl 1): S300-S304.12. Jones DH, Kenkel JM, Fagien S, et al. Proper technique for administration of ATX-101 (Deoxycholic acid injection): Insights from an injection practicum and roundtable discussion. Dermatol Surg 2016 Nov;42(Suppl 1): S275-S281.13. Cohen JL, Chen DL, Green JB, Joseph JH. Additional thoughts on the new treatment Kybella. Sem Cutan Med Surg 2015 Sep;34(3):138-13914. Deoxycholic acid (Kybella) for double chin (no authors listed). Med Lett Drugs Ther 2015 Dec 7;57(1483):165-166.15. Dayan SH, Humphrey S. Jones DH, et al. Overview of ATX-101 (Deoxycholic acid injection): a non surgical approach for reduction of submental fat. Dermatol Surg 2016 Nov;42(Suppl 1): S263-S270.

Corresponding author:Elie [email protected]

usually takes about 10-15 minutes. Kybella® is supplied in 2 ml vials (10 mg/mL) and does not require reconstitution. The average initial treatment used by the authors is one to three vials (2 to 6 ml). Depending on the amount of submental fat, follow-up treatments may require lower volumes than the initial treatment. Injections are usually repeated 4-6 weeks apart. Each patient can receive up to 6 treatments.

Patients should be marked before injections using familiar anatomical landmarks (Fig. 1). Patients are marked at the mandibular border. Another marking 1.5-2 cm below the first mark is made. The space between the markings is a “non-injection zone” in order to protect the marginal mandibular branch of the facial nerve. The anterior border of the strenocleidomastoid muscle should be marked bilaterally as the lateral extent. Injections should only target the submental region. A transfer tattoo is placed over the area of fat deposit and moistened with water. This allows a dotted grid to be transferred over the treatment area with 1 cm evenly spaced marks (Fig. 1). Kybella® diffuses about 1 cm; so keeping the injections evenly spaced ensures proper injection and prevents tissue necrosis. Dots that are not over fat or fall outside the treatment area should not be injected and removed with an alcohol wipe to prevent confusion. The average safe injection zone contains 20 dots and thus 4 mLs of Kybella® are injected (0.2 mL per injection).

The results to date are promising. Our patients had a 1-point or 2-point improvement in CR-SMFRS (Figs. 2,3). Our adverse events are similar to those seen in the North American and European trials. In these trials, the adverse events included: pain (70%), swelling (87%), bruising (72%), numbness (66%), erythema (27%), and induration (23%), with 1% of patients discontinuing treatment due to adverse events6,8,9,11. None of our patients have experienced marginal mandibular branch of facial nerve injury (Figs. 2,3,4).

CONCLUSIONIn human body, deoxycholic acid is used to emulsify

fat for absorption in the intestine. In facial anti-aging and esthetic medicine, deoxycholic acid injection (10mg/mL) is available as a clear, colorless, sterile solution for submental, subcutaneous use: Kybella®

(Kythera Biopharmaceuticals, USA) is a cytolytic drug

Fig. 1. Dotted grid with 1 cm evenly spaced marks.

Fig. 2. Patient treated with Kybella®. Note the reduction of submental fat.

Fig. 3. Patient treated with Kybella®. Note the reduction of submental fat.

Fig. 4. Patient after Kybella® injection. Note the minimal erythema and swelling.


9594

and sharing experiences and insights regarding the treatment I should provide.

Because of that, I did not miss any study club meetings. Sometimes, I have presented cases that I was not proud of. But to my surprise, there was always an educational value you could collect from these images and from the feedback of attending colleagues. It was an excellent peer-to peer learning experience by sharing these valuable photos.

Dental photography obviously helped me to personalize my website with patients I treated, not from generic images that I could buy. This made me proud and always motivated to invite my patient to visit my website.

Dental photography also provided excellent communication between myself and the dental lab technician. It improved patient care by ordering fewer remakes, improved shade matching, and personalized the treatment for every patient. Also, it made the technician do his/her utmost effort in order to reach the best outcome. These images helped the discussion to be fruitful and made the technician to be an integral part of the interdisciplinary team.

A commitment to dental photography is essential to successful interdisciplinary patient care and could play an important role in helping to achieve a predictable outcome. Thanks to the discipline of dental photography my patients were better served, my referrals increased, and I gained an excellent reputation in my dental and patient communities.

Professor Tony Daher is a graduate of of Saint-Joseph University (USJ), Faculty of Dental Medicine, Beirut, Lebanon - Paris University - University of California at Los Angeles (UCLA) - and University of Southern California (USC).

He is a Diplomate of the American Board of Prosthodontics, Fellow of the American College of Prosthodontists and the International College of Dentists.

Professor Daher is the Co-director of the Global Dental Implant Academy (GDIA), former Associate Professor at Loma Linda University, Visiting Clinical Professor at Saint-Joseph University, past clinic director of the international student program at USC, and past director of Advanced Prosthodontic Program at Loma Linda University.

He has active membership in numerous dental and prosthodontic organizations. He maintains a private practice limited to Prosthodontics and Implant Dentistry in LaVerne, California, USA. He has written many scientific articles, textbook chapters, and eBooks chapters and has lectured nationally and internationally on Prosthodontics and dental implants.

[email protected]

It took me few years to understand how dental photography plays an important role in the treatment of complex patient clinical situations. The first time I had to take photos of my clinical cases was in 1986, during the prosthodontic residency program at UCLA. We did not have a choice because it was a part of the residency requirements. Looking back, I indeed do not regret it at all.

Certainly, learning to take patient photographs was not an easy task. At that time, we did not have digital cameras and the feedback to see how the images turnout, was delayed to few days. So achieving improvement was slow, but with persistence, I made it happen. Nowadays, learning dental photography is easy. A small investment in time and money can make you achieve this desired skill.

It was an important turning point when I started incorporating dental photography in documenting my clinical cases. As I viewed my patient clinical images, I could see the problems, criticize previous work, and understand complex diagnostic issues more easily. When I shared them with my peers, it gave me the opportunity to improve my diagnostic skills and be able to deliver better patient care.

The practice of taking photographs and presenting them in the treatment planning sessions during my residency enabled me and my fellow residents to diagnose better and to criticize the final product after the treatment was achieved. It was an utmost experience in my prosthodontic education.

This habit of taking photographs continues during my dental carrier. I was able to provide more effective personalized consultations: there was no need to make the patients hold face mirrors and show them the problems. Instead, the photos helped in comprehending their dental problems and their solutions. My case acceptance increased dramatically. By documenting pre and post-treatment images, I was better able to evaluate the treatment I provided and I became critical

in evaluating esthetics, contour emergence profiles, gingival health, smiles, oral hygiene, and many other clinical details. Looking at my work, after hours, in a relaxed atmosphere, gave me the incentive to criticize my work and to get motivated to do it better. It was the biggest impact on my personal evolution and on the quality of my dental practice.

Dental photography was also essential when I met with other dental specialists and general practitioners in order to discuss treatment plannings that I developed for my patients. Dental photos and articulated casts using ear-bow and jaw recorders and tracers, helped me to lead the conversation and get many good advices from them. Bottom line, these comprehensive treatment plannings are and should be restoratively driven to achieve the desired predictable outcome. These images helped us, as a team, to diagnose problems and successfully plan treatments.

Without dental photos, radiographs, and articulated casts, the study club discussion can turn around and around without pinpointing to problems and their solutions. It created an atmosphere of discussions

Importance of dental photography in the practice of complex dentistry.Tony Daher, Dr. Chir. Dent., MS (Education), FACP, FICD, Diplomate of the American Board of Prosthodontics, Fellow of Pierre Fauchard Academy

Tips and Tools for Dentists




2- Based on morphology2-a- conical ST: are normally peg shaped and are

localized between maxillary central incisors, and known as mesiodens.

2-b- tuberculate ST: have more than one cusp or tubercle and are often localized palatally to central maxillary incisors.

2-c- supplemental teeth: are a duplicate of teeth in normal series (Fig. 4). They are usually smaller than the normal tooth type they resemble and usually occur distal to the normal tooth series. They are mostly found in lateral incisor, premolar and molar regions.

2-d- odontomes: are quoted as ST but, in fact, they are odontogenic tumors that present either as compound odontoma (a gathering of tiny teeth-like structures) or complex odontoma (a diffuse and disorganized mass of dental hard tissues).

3-Based on orientation3-a- vertical or normal3-b- inverted 3-c- horizontal

4- Based on position: 4-a- buccal4-b- palatal (for maxilla) 4-c- lingual (for mandible) 4-d- transverse

From a different standpoint, ST are classified into different categories:

1- Isolated supernumerary teeth (non-syndromic ST) such as mesiodens and distomolars (fourth molars): these are classified as individual supernumeraries either in premolar regions, maxillary central incisor regions (mesiodens) or maxillary tuberosity region (distomolars).

Mesiodens are obviously the most common supernumerary teeth: they are localized in the anterior maxillary midline area and represent 90 to 98% of all supernumerary teeth (Primosch, 1981; Tay et al., 1984). The next most common supernumeraries are the “fourth molars” or “distomolars” (localized distal to maxillary third molars), mandibular premolars, and maxillary lateral incisors (Shaefer, Hine, and Levy, 1983).

2- Single supernumerary teeth (SSNT) are

Fig. 1a. Palatal mesiodens. Fig. 1b. Same mesiodens surgically extracted.

Fig. 2. Right and left distomolars in the maxilla (distal to 18 and 28).

Fig. 3. Orthopantomogram of 11-year-old patient, 5 months at the beginning of orthodontic treatment. Supernumerary premolar (appearing) between roots of right mandibular second premolar (45) and first molar (46).

Fig. 4. Occlusal view of anterior maxillary region showing supernumerary right lateral incisor, adjacent to erupting canine.

INTRODUCTIONSupernumerary teeth -ST- are rare anomalies of the

dento-maxillo-facial complex1,2,18, consisting of one or more extra teeth. ST might be single or multiple, unilateral or bilateral, and at any location of maxillary and mandibular dental arches. Prevalence of ST is between 0.15% and 3.9% (Bergstrom, 1977; McKibben and Brearley, 1971). Demiriz and co-workers3 conducted a survey on 7,348 people to determine the prevalence and characteristics of supernumerary teeth. The study was carried out on patients aged over 18 years (3,212 females and 4,136 males): 123 (2.14%) affected patients (69 females and 54 males) were observed with a female:male ratio of 1.28:1. One hundred and fifty-six ST were observed in all affected patients.

Extra teeth are five times less frequent in primary dentition (Grahnen, 1961; Sedano and Gorlin, 1969; Sykaras, 1975) and according to Primosch (1981), ST are usually found as a single tooth in 76 to 78% of cases.

ST are classically classified into two morphological types: supplemental and rudimentary. Supplemental display a normal size and shape, and usually resemble the group of teeth they are associated with (such as incisors and molars), whereas rudimentary are smaller with a tuberculated shape (Primosch,1981).

CLASSIFICATION Morphology, location, position, and orientation are

the usual criterias used to classify ST4,5,6:

1- Based on location1-a- mesiodens: it is usually located in anterior

maxilla, between the two maxillary central incisors, mostly in palatal position (Figs.1a,1b). Aoun and Nasseh7 reported a very rare case of an impacted and inverted mesiodens located in the nasopalatine canal and incidentally discovered upon a Cone Beam Computed Tomography -CBCT- examination.

1-b- paramolar and distomolar: Located in posterior maxilla and mandible. In an epidemiological survey on 25,186 subjects, Cassetta and co-workers (2014) studied the morphological and topographical characteristics of posterior supernumerary molar teeth: diagnostic of hyperdontia was formulated during clinical and radiological examinations based on orthopantomograms (Fig. 2). 61 posterior ST were found in 45 patients. Supernumerary molars were mostly of tuberculate shape (56.8%) and paramolars teeth (64.9%) were more common than distomolars. 54% of teeth were erupted on dental arch. In this retrospective study, the prevalence of supernumerary molars was 0.18%. The conical morphology and paramolar position were the most common shape and position (Cassetta et al., 2014).

1-c- parapremolar: located in premolar region (Fig. 3).

Supernumerary teeth: A clinical reminder.

Marianne Saadé*, Dr. Chir. Dent. 2018

AbstractSupernumerary teeth are defined as teeth or teeth-like structures in excess of the normal-regular-number. These

extra teeth can be observed in any location of the dental arch and can affect any tooth. They are found in both primary and permanent dentitions and are usually classified according to location and form. These structures are diagnosed after clinical examination and thorough radiological and imaging investigations. Their management is often surgical but should be part of a comprehensive and multidisciplinary treatment planning. Orthodontics is rarely a second treatment option, ensuring, if needed, adequate eruption of these extra teeth and their proper alignment on arch.

This clinical reminder aims to help dental practitioners revisit supernumerary teeth in order to improve clinical processes and patient care.

* Dental Student, Undergraduate Program, Saint-Joseph University, Faculty of Dental Medicine, Beirut, Lebanon

Dental Pathology



paper in which they reported the association of ST with Ehlers-Danlos syndrome (EDS), a group of genetic connective tissue disorders featuring loose (hyper-flexible) joints, finger and spine deformities, myalgia, stretchy skin, tendency to abnormal scar formation, epicanthic folds, myopia, strabismus, blue sclera, lack of ear lobes, hyperelastic skin, Gorlin’s sign (patients are able to touch the tip of their nose with their tongue), enamel hypoplasia, periodontal disease, halitosis, tendency to gingival bleeding and oral mucosal ulcers. EDS is known to affect 1 in 5,000 people globally.

Most published papers report that 80% to 90% of all supernumerary teeth occur in the maxilla and that half of them are observed in the anterior maxillary region9 (Bergstrom, 1977-Primosch, 1981-Hattab et al., 1994). Several papers reported cases of supernumerary teeth in mandibular anterior region, mostly in canine and incisor areas (Stafne,1932) and Krayer was the first author to report (1989) a supernumerary tooth “at the facial of a mandibular lateral incisor”.

DIAGNOSIS15,16,17,19

Supernumerary teeth rarely erupt spontaneously and are usually diagnosed radiographically by means of conventional radiographs (such as periapicals, occlusals, and orthopantomograms) or imaging techniques (such as Computed Tomography-CT and Cone Beam Computed Tomography-CBCT).

Panoramic radiographs are not enough to identify supernumerary teeth and clinical experience has proven that a combination of radiographic techniques are necessary for an accurate localization of supernumeraries: vertical tube shift and horizontal tube shift are commonly used radiological techniques (Mallineni et al., 2012). In 2013 (Journal of Dental Education) Toureno and associates suggested 2D and 3D methods to identify supernumerary teeth: authors claimed that their guidelines may reduce treatment errors and improve communication.

Recognition and diagnosis of supernumerary teeth are usually easy and straightforward but their treatment modalities are somehow debatable.

Fig. 7b. Panoramic of same patient (7a). It is important to note the presence of 5 permanent mandibular incisors, among them, 2 unerupted.

Fig. 7c. Mandibular arch following orthodontic treatment involving extraction of a supernumerary incisor (Patient 7a).

Fig. 7d. Panoramic radiograph after orthodontic treatment (Patient 7a).

Fig. 7a. Mandibular view of 7 year-5 month-old patient presenting with 3 permanent incisors and 2 deciduous ones.

commonly observed in anterior region of maxilla (Figs. 5a, 5b), whereas multiple supernumerary teeth (MSNT) usually prevail in premolar regions of mandible, and it is likely that these two different pathologies have different etiologies. Multiple mesiodens are termed mesiodentes; they appear as unilateral or bilateral, they often fail to erupt, and frequently alter position and eruption path of maxillary permanent incisors. Familial mesiodentes were reported in siblings, twins, and sequential generations of a single family (McKibben and Brearley, 1971; Brook, 1984).

Most cases of multiple supernumerary teeth (in particular mesiodentes) are associated with congenital craniofacial anomalies8 such as cleft lip and palate (Bohn,1963), cleido-cranial dysplasia12 (Figs. 6a, 6b)(Koch and Hammer, 1978; Jensen and Kreiborg, 1990; Becker et al., 1997; Golan et al., 2003; Khambete and Kumar, 2012), Gardner’s syndrome or Familial Adenomatous Polyposis (Gorlin, Pindborg, and Cohen, 1976; Ramaglia et al., 2007; Amla et al., 2009).

Multiple ST can be idiopathic and not related to a genetic syndrome: Al-Iryani and Ali (2017) reported a rare case in which they observed twelve impacted ST in a non syndromic female patient, aged 16 years, who presented with overretained deciduous teeth. This case was diagnosed as idiopathic hyperdontia and in such clinical situations, patients must be managed by a multidisciplinary approach (orthodontics, pediatric dentistry, and oral surgery).

ETIOLOGYThere is no specific and evidence-based cause of

hyperdontia. The most supported etiological theories are the dichotomy theory (that associates these extra teeth with an extra tooth bud that forms the ST) and the theory that involves a “hyperactivity of the dental lamina” that results in its splitting (Primosch, 1981; Shaefe, Hine, and Levy, 1983; Sedano, 1969; Knychalska-Karwan et al., 1984). Genetic factors are also incriminated among etiological factors determining the development of supernumerary teeth: According to Soames and Southam (1993), most cases of multiple supernumerary teeth are observed in genetic craniofacial development syndromes, such as cleido-cranial dysplasia, cleft lip and palate and Gardner’s syndrome.

In 1994, Melamed and co-workers published a

Fig. 5a. Single supernumerary tooth preventing eruption of maxillary left central incisor (age: 8 years, 7 months).

Fig. 5b. Panoramic radiograph of same patient (5a) after surgical removal of supernumerary tooth and orthodontic traction of impacted right central incisor. This radiograph revealed initial stage of 2 new supernumerary teeth on mandibular right side (premolar sector).

Fig. 6a. Panoramic radiograph of a cleido-cranial dysplasia case.

Fig. 6b. Mandibular occlusal radiograph of same patient (Fig. 6a).


soon as it has been discovered, ideally before the age of 5 years so that root formation of associate permanent incisor is still incomplete. Koch and co-workers (1986) studied the indications for surgical removal of ST in the premaxilla: he reported that immediate surgical removal of ST is not mandatory if no associated pathology is present.

Högström and Andersson10 suggested two therapeutic options for anterior ST in children: the first option involved the surgical removal of the supernumerary as soon as it is noticed and diagnosed. The second one advocates that supernumerary be left in situ until root development of adjacent teeth is complete. Potential disadvantages related to this

second option include loss of eruptive force of adjacent teeth, space loss and arch crowding, and, sometimes possible midline shifts.

Garvey and co-workers6 recommended that extraction of ST is not always the best treatment: in this regard ST should be monitored without surgical removal if adequate eruption of related teeth occurs, if there is no indication for orthodontic treatment or if there is no associated pathology with the supernumerary.

Shah and associates11 recommend the monitoring of ST with yearly radiographic review if these supernumeraries cause no complications and are not likely to negatively interfere with orthodontic treatment.

Table 1. The Decision Support System -DSS (From Amarlal and Muthu, Indian J Dent Res, 2013).

COMPLICATIONS ASSOCIATED WITH SUPERNUMERARIES

ST are frequently asymptomatic (Rodriguez-Armijo et al., 1996) but in rare cases they can cause a variety of complications, and if one or more complications occur or is anticipated, immediate surgical removal of the supernumerary (ies) is indicated. These complications include:

1- Periodontal lesions of adjacent teeth.2- Interference with the eruption of adjacent teeth

and /or delayed eruption(s) of permanent teeth or failure to erupt (Figs. 7a, 7b, 7c, 7d).

3- Displacement of permanent teeth, leading to malpositions and resulting arch length discrepancy, poor esthetic appearance and functional impairment.

4- Enlargement of follicular sacs around supernumeraries.

5- Dentigerous (follicular) cyst and odontogenic keratocyst formations around supernumeraries.

6- Mechanical pressure on adjacent teeth and resulting root resorptions (these roots resorptions leading sometimes to loss of tooth/teeth vitality).

7- Eruption of supernumerary teeth into the nasal cavity and/or maxillary sinus.

8- Loss of vitality of one or more teeth adjacent to the supernumerary teeth (Primosch, 1981-Bodin et al., 1981).

9- Facial pain.10- Retained deciduous teeth. 11- Midline diastema (caused by erupted and/or

unerupted mesiodens). A retrospective study reported that 10% of cases with supernumerary teeth displayed midline diastema (Asaumi et al.,2004).

12- Patients presenting tuberculate or anterior supernumerary teeth at a relatively early age have a 24% possibility of developing single or multiple supernumerary premolars at late age (King et al.,1993;Solares and Romero,2004).

13- Vinothkumar and co-workers (2017) reported a case of a dilacerated maxillary central incisor fused to a supernumerary tooth: On CBCT, this unusual radiological presentation displayed a dilacerated maxillary central incisor fused to a supernumerary tooth unusually appearing as a

labial tubercle. The dilacerated central incisor was endodontically treated with the aid of a dental operating microscope and root canal was obturated with a combination of single cone, carrier based, and cold flowable gutta-percha obturation system. The tooth remained asymptomatic, with no sign of infection or endodontic failure symptoms, for 18 months.

TREATMENT PLANNING AND CURRENT MANAGEMENT15,16,17,19

A multidisciplinary approach (orthodontics, pediatric dentistry, and oral surgery) is mandatory for an efficient management of supernumerary teeth, especially if they are multiple, syndromic, and/or associated with complications.

As soon as supernumerary teeth are identified and diagnosed, oral surgeon, pediatric dentist, and orthodontist have to make an efficient decision: many authors advocate early intervention on supernumerary teeth, treatment options for management depending on orientation and position of the supernumeraries, age of the patient and any real or possible associated complications. Koch and co-workers (1986) studied the indications for surgical removal of supernumerary teeth in the premaxilla: they recommended that removal of those extra teeth is not essential if there was no associated pathology.

Surgical removal is not systematically a treatment of choice: Högström and Andersson (1987) studied the complications related to surgical removal of anterior supernumerary teeth in children: they suggested two different opinions where the supernumeraries should be removed as early as identified, or dentist should wait until complete root formation of adjacent teeth occurs.

Foley (2004) studied the surgical removal of supernumerary teeth and the fate of incisor eruption: he reported that in some cases based on impacted teeth angulations caused by supernumerary teeth, an orthodontic bracket should be bonded and chain inserted at the time of supernumerary tooth surgical removal, in order to re-initiate eruption of the impacted permanent tooth.

In a clinical study of 375 children, Rotberg (1984) addressed early vs late removal of mesiodens and he recommended that mesiodens should be removed as

103102

GUIDE FOR CONTRIBUTORS AND AUTHORSISSN 1810-9632

REVIEWING AND EDITING PROCESS.All submitted manuscripts will be subject to the

peer-refereeing process and submission of amanuscript implies that the work accomplished byauthor(s) has not been published (or submitted forpublication) previously in its present form, in Englishor in any other language. Submission and peer-reviewof all manuscripts are conducted exclusively onlineand all correspondence, including the Editor-in-Chieffinal decision and request(s) for revisions, areelectronically conducted (by e-mail).

Manuscripts will be reviewed by the Editor-in-Chief,one (or two) editorial consultant(s) and, at least, twospecialized reviewers, and in case of conflict ofopinion, an additional reviewer or special consultantwill be asked to act as adjudicator. Reviews aredouble-blind (for authors and reviewers) andmanuscripts accepted for publication will be edited inconsultation with author(s), to ensure conciseness,clarity and stylistic consistency. Studies that drawconclusions from statistical evidence will have thestatistical analysis reviewed by biostatistics andepidemiology consultants.Manuscripts will kindly be addressed to: JLDA Editor-in-Chief, Ziad Noujeim, at the following electronic mail: [email protected]

GUIDELINES AND MANUSCRIPT FORMAT.The JLDA follows recommendations of the

International of Medical Journals Editors («Vancouver»style ) in regard to preparation of manuscripts andauthorship (Ann Intern Med 1997; 126: 36-47 andupdate October 2007). Submitted manuscripts notcomplying with the guide for authors will kindly bereturned to authors for revision and resubmission.

Manuscripts should be submitted exclusively inEnglish according to the Oxford English Dictionary orWebsters.

1. Title page: the following data should be providedon title page, in the order given below:- title should be informative and concise (avoid

formulae and abbreviations)- regarding author(s) names and affiliations, present

author(s) (academic or private) affiliation(s) whereactual work was implemented, below the names.

- indicate (at the end of the manuscript) the name ande-mail address of the corresponding author (handles

correspondence). - Indicate your manuscript type (case report, review,

mini-review, research study, technical note, shortcommunication, pilot study, letter to the editor,…etc…)

2. Abstract: submit a factual/concise abstract (notexceeding 300 words) that should be typed on aseparate page following the title page: abstract shouldbe structured as follows: a) statement of the problem,b) purpose of the study, c) materials and methods(ifany), d) results (if any), e) conclusion.

3. Main text:* clinical reports/case reports/technical notes:should describe author(s) methods for meeting patienttreatment challenge and be no longer than 5-6 pages(A4).

* review article /mini review:may concern either clinical or basic scientific topics.Standard length of a review article is 5, 000-7, 000words, and mini review 2, 000-3, 000/

* research studies:should follow IMRAD format (introduction, objectiveof the study, working hypothesis-if any, material andmethods-including statistical method(s) used, resultsand discussion).

* letters to the editor:should be up to 800 words in length : they usuallyreply to a material published in JLDA in order to makeconstructive comments/criticism or introduce a pointof view. They should be accompanied by 5 to 10references, but no illustrations. These letters do notcarry an abstract.

* abbreviations:define them if they are not standard and ensure

consistency throughout the manuscript.

* subdivision of the manuscript:divide manuscript into defined and numbered sections.Subsections should be numbered 1.1 (then 1.1.1, 1.1.2,1.1.3, …), 1.2 (then 1.2.1, 1.2.2, 1.2.3, …) etc…Provide a brief heading to each subsection and makesure that each heading appears on each subsection andmake sure that each heading appears on its ownseparate line. Note that abstract shouldn't be includedin section numbering.

119 Journal of the Lebanese Dental AssociationVolume 48 - Nº 2 - December 2013

JLDA June 2015:JLDA 9/25/15 1:29 PM Page 119

Recently navigation-guided extraction of impacted ST was suggested as a novel preoperative and intraoperative computer-assisted surgical treatment for complicated impacted ST (Wang et al., 2017), knowing that conventional surgical treatment involving surgical extractions is often challenging in certain complicated cases where the risk of injury to young permanent tooth germs and fragile roots, is not negligible.

In some situations, ST forbid adjacent teeth from erupting, leading to their impaction, a situation commonly observed in cleidocranial dysplasia12, a rare congenital, autosomal, dominant disorder featuring skeletal abnormalities and multiple ST; those ST should be surgically removed in collaboration with the treating orthodontist and pediatric dentist12. Moreover, ST may damage roots of adjacent tooth/teeth, necessitating its removal; Murali and co-workers13 reported a rare case in which a supernumerary premolar resorbed the distal root of permanent mandibular first molar: the latter was extracted and supernumerary premolar orthodontically moved on dental arch.

In 2013, Amarlal and Muthu14 suggested a decision support system -DSS- which helps dental practitioners in overcoming the multiple controversies regarding ST timing of surgical removal (Table 1). The goal of this DSS is to assist dentists with diagnosis and treatment planning in cases of either erupted or unerupted ST: Erupted ST should be preferentially extracted except in cases where ST should be retained (for example if adjacent tooth is clinically missing or if supernumerary tooth has to be used as an abutment, or in cases where reshaping of mesiodens is executed when the primary incisors is lost prematurely and the permanent incisor is not yet erupted. Stermer Beyer-Olsen et al., 1985). Unerupted ST not associated with complications can be kept under periodic monitoring whereas if associated with any complications, they should be surgically removed.

REFERENCES1- Gardiner JH. Supernumerary teeth. Dent Pract Dent Rec 1961;12:63-73.2- Shafer WG, Hine MK, Levy BM. A Textbook of Oral Pathology. Fourth Edition. Philadelphia: W B Saunders Co., 1983;47-50.3- Demeriz L, Durmuslar MC, Misir AF. Prevalence and characteristics of supernumerary teeth: A survey on 7348 people. J Int Soc Prev Community Dent 2015 May;5(Suppl 1):39-43.

4- Mallineni SK. Supernumerary teeth: Review of the literature with recent updates. Conference Papers in Science. Volume 2014, September 2; Article ID 764050, 6 pages (Hindawi Publishing Corporation) 5- Mitchell L. Supernumerary teeth. Dent Update 1989 Mar;16(2):65-69.6- Garvey MT, Barry HJ, Blake M. Supernumerary teeth-an overview of classification, diagnosis and management. J Can Dent Assoc 1999;65:612-616.7- Aoun G, Nasseh I. Mesiodens within the nasopalatine canal: An exceptional entity. Clin Pract 2016 Dec 7;6(4):903.8- Gorlin RJ, Cohen MM, Hennekam RCM. Syndromes of the Head and Neck. Fourth Edition. Oxford University Press, 2001.9- Primosch RE. Anterior supernumerary teeth-assessment and surgical intervention in children. Pediatr Dent 1981; 3:204-215.10- Högström A, Andersson L. Complications related to surgical removal of anterior supernumerary teeth in children. ASDC J Dent Child 1987 Sep-Oct;54(5):341-343.11- Shah A, Gill DS, Tredwin C, Naini FB. Diagnosis and management of supernumerary teeth. Dent Update 2008 Oct;35(8):510-512,514-516,519-520.12. Chalala C, Noujeim Z, Abou Chebel N, Saadé A. Multidisciplinary management of cleidocranial dysplasia. J World Fed Orthod 2015;4:31-39.13. Murali RV, Gnanashanmugan K, Rajasekar L et al. A rare case of impacted supernumerary premolar causing resorption of mandibular first molar. J Pharm Bioallied Sci 2015 Apr;7:309-313.14- Amarlal D, Muthu MS. Supernumerary teeth: Review of literature and decision support system. Indian J Dent Res 2013; 24: 117-122.15- Scheiner MA, Sampson WJ. Supernumerary teeth: a review of the literature and four case reports. Aust Dent J 1997; 42:160-165.16- Rajab ID, Hamdan MAM. Supernumerary teeth: review of the literature and a survey of 152 cases. Int J Pediatr Dent 2002; 12: 244-254.17- Mason C, Rule DC, Hopper C. Multiple supernumeraries: the importance of clinical and radiographic follow-up. Dentomaxillofac Radiol 1996; 25: 109-113.18- Schulze C. Developmental abnormalities of the teeth and jaws. Thomas's Oral Pathology. Saint Louis, Misouri, USA: CV Mosby; 1970 (Gorlin RJ, Goldman HM, editors).19- Russell KA, Folwarczna MA. Mesiodens-Diagnosis and management of a common supernumerary tooth. J Canad Dent Assoc 2003 June; 69(6): 362-366.

Correspondin author:Marianne Saadé[email protected]



104

GUIDE FOR CONTRIBUTORS AND AUTHORSISSN 1810-9632

* conflict of interest:at the end of the text and under a subheading «Conflictof interest statement», authors should disclose anyfinancial /personal relationship(s) with otherorganizations/associations/people/that couldinappropriately influence (bias) their work.Examples of potential conflicts include employement,consultancies, honoraria, patentregistrations/applications, paid expert testimony, stockownership, grants or others sources of funding.All sources of funding should be declared as anacknowledgement at the end of the text and authorsshould declare if sponsor(s) have a role in the studydesign, analysis, collection and interpretation of data.And if the study sponsor(s) are not involved in thestudy, authors should so state.* acknowledgements:persons/professionals who provided technical help,writing assistance, consultancy, support… should belisted in an acknowledgements section, at the end ofthe manuscript.* figures:should be numbered consecutively in accordance withtheir appearance in the text and figure legends listed ona separate page.High-resolution graphics should be provided separatefrom the main text file.* tables :should be numbered consecutively in accordance withtheir appearance in the text. Kindly place footnotes totables below the table body and indicate them withsuperscript lowercase letters. Avoid vertical rules.* references :references to dental/medical/biomedical… literatureshould be indicated by superscript Arabic numerals insquare parentheses and if a reference is cited more thanonce in the text, the same number must be used eachtime. Reference style follows the «Vancouver» formatstated in the «Uniform requirements for manuscriptssubmitted to biomedical journals» ( updated October2007). Titles of journals are to be abbreviatedaccording to Index Medicus style.* illustrations:- Number the illustrations according to their sequence

in the text.- Produce images that fit the desired size of printed

version.- Use uniform lettering and sizing of your original

artwork

- Convert images to TIFF format:1- colour or greyscale photographs: use a minimum of

300 dpi2- bitmapped line drawings: use a minimum of 1, 000

dpi3- combinations bitmapped line/colour or greyscale:

use a minimum of 500 dpi.Kindly:- do not supply files too low in resolution (GIF, BMP,

PICT, WPG)- do not submit graphics that are disproportionately

large for the content.For colour illustrations, please make sure that

artwork files are in TIFF format and with theappropriate resolution.

COPYRIGHT RELEASEThe following statement must accompany any

submitted manuscript before it can be reviewed forpublication, and this statement must be signed by ALLauthors:

«The undersigned author(s) transfer(s) all copyrightownership of the manuscript (title of manuscript to bestated) to the editorial board of the Journal of theLebanese Dental Association, if the manuscript ispublished in the JLDA. The undersigned author(s)warrant(s) the manuscript is original, is not underconsideration for publication by any other printedjournal/electronic medium and has not been publishedpreviously.

The author(s) confirm that he/she/they havereviewed and approved the final version of themanuscript».

PERMISSION AND WAIVER- Permission of author(s) and publisher (LDA) must be

obtained for the direct use of material (text, photos,drawings) under copyright that is not the property ofthe author(s).

- Waivers must be obtained for photographs showingpersons. When such waivers are not supplied, faceswill be masked to prevent identification.

120Journal of the Lebanese Dental AssociationVolume 48 - Nº 2 - December 2013

JLDA June 2015:JLDA 9/25/15 1:29 PM Page 120


Senior Associate Editors · 2 3 Editorial Advisors Essam Osman, BDS, MSD, Ph.D. Vice-President for...

Documents

Transcript of Senior Associate Editors · 2 3 Editorial Advisors Essam Osman, BDS, MSD, Ph.D. Vice-President for...