PRE OPERATIVE PRE OPERATIVE EVALUATION OF IMPLANT EVALUATION OF IMPLANT

PATIENTSPATIENTS

Shahnaz KhadarCRI

Contents Contents DefinitionHistoryClassificationIndicationsPretreatment evaluationMedical & Dental historyContraindicationsClinical examinationRadiographic examinationconclusion

Definition Definition Implantation is defined as the insertion of any object or material, such as an alloplastic substance or other tissue, either partially or completely, into the body for therapeutic, diagnostic, prosthetic or experimental purposes.

HISTORYHISTORYCarved bamboo pegs were used 4000yrs

ago in ChinaRoot form metal pegs- Egypt 2000 yrs

backArchaeological museum at Harvard houses

an implant made of shell dating back to 600 AD

Albucasise de condue (1963- 1013) used ox bone , first documented placement of implants.

1809, Maggiolo fabricated gold roots that were fixed to pivot teeth by springs.

•Per Ingvar Branemark - Osseo integration•1965- first titanium dental implant placed in a human volunteer.

X ray of titanium chamber embedded in rabbit femur

Panoramic radiograph of historic dental implants, taken 1978

CLASSIFICATION OF CLASSIFICATION OF IMPLANTSIMPLANTS

Indications Indications Edentuluos patients -implant assisted removable

prostheses -implant supported fixed

prosthesesPartially edentuluos patients

Why implants??Why implants??Maintains boneRestore and maintain occlusal vertical

dimensionsImproves esthetics,phonetics,occlusionImproves masticatory functionImproves psychological health

Pre treatment evaluationPre treatment evaluationChief complaint-Patient’s concernPatient’s expectation

Medical historyMedical historyThorough medical history should be

documented.Review for conditions that might

pose a risk for adverse reactions/complications.

Laboratory tests to rule out conditions that might be contraindication/risk factor.

Medical clearance from treating physician.

ASA PHYSICAL STATUS ASA PHYSICAL STATUS CLASSIFICATIONCLASSIFICATIONASA I - A normal healthy patient without systemic

diseaseASA II- A patient with mild systemic diseaseASA III- A patient with severe systemic disease

that limits activity but is not incapacitatingASA IV- A patient with an incapacitating systemic

disease that is a constant threat to life.ASA V- A moribund patient not expected to

survive 24 hours without operationASA E- Emergency operation

Contraindications Contraindications Medical

• acute infectious diseases – absolute, but temporarily; wait for recovery

• chemotherapy – absolute, but temporarily; reduced immune status

• systemic bisphosphonate medication (≥2 yr)

– risk of bisphosphonate-induced osteonecrosis (BON)

• renal osteodystrophia – increased risk for infection, reduced bone density

• severe psychosis

– absolute; risk of regarding the implant as foreign body and requesting removal despite of successful osseointegration

• depression – relativeNU Zitzman et al Australian Dental Journal 2008; 53:(1 Suppl): S3–S10

• pregnancy– absolute, but temporarily; to avoid additional stress and radiation exposure

• unfinished cranial growth with incomplete tooth eruption

– relative, but temporarily; to avoid any harm to the growth plates, to avoid inadequate implant position in relation to the residual dentition

intraoral

• pathologic findings at the oral soft- and/or hard tissues

– temporarily; increased risk for infection, wait until healing is completed

NU Zitzman et al Australian Dental Journal 2008; 53:(1 Suppl): S3–S10

Increased risk

post head and neck radiation therapy

– reduced bone remodelling, risk of osteoradionecrosis, implant placement 6–8 weeks before or ≥1 yr after radiotherapy

• osteoporosis – reduced bone to implant contact

• uncontrolled diabetes– wound healing problems (impaired immunity, microvascular diseases)

• status post chemotherapy, immuno-suppressants or steroid long-term medication, HIV infection

– wound healing problems, medical advice required

• alcohol and drug abuse, heavy smoking ≥20 cig/d

– wound healing problems, locally reduced vascularization7

• history of aggressive periodontitis

– increased risk to develop peri-implantitis

NU zitzman et al Australian Dental Journal 2008; 53:(1 Suppl): S3–S10

Habits and behavioral Habits and behavioral considerationsconsiderations

◦Smoking & tobacco use *Adversely affects implant success

through its effect on bone metabolism◦Para functional habits * Repeated lateral forces can be

detrimental to osseointegration process.

◦Substance abuse * Psychological problems , non

compliance * Impaired organ function

Dental Dental historyhistoryOral hygiene status and

practicesCompliance with past dental

recommendationsPrevious experience with

surgery and prostheticsAttitude and motivation

towards implants

Clinical Clinical examinationexamination

Facial proportionsFacial symmetryFacial convexityLip and cheek supportIntermaxillary relationLip length and incisal show

Intraoral Intraoral examinationexaminationInfections , lesions and

pathologic conditionsOverall dental &

periodontal healthOcclusionJaw relationTMJ conditionMouth opening

Soft tissue evaluationSoft tissue evaluationQuality( keratinized/ non keratinized)

Quantity Location Frenum attachments

Hard tissue evaluationHard tissue evaluationClinically and radiographically

Palpate for anatomical defects, concavities and undercuts

Intraoral bone mapping

Evaluation of implant sitesEvaluation of implant sitesAlveolar bone Atleast 1.0 to 1.5mm of bone around implantInterdental space

Buccolingual width > 6mm

Interocclusal space

Diagnostic study modelsDiagnostic study modelsEvaluate space availableDetermine potential limitations of planned

treatmentUseful while replacing multiple teeth or in case

of malocclusion.

Radiographic examinationRadiographic examinationQuality, quantity and location and volume of alveolar

boneIdentify vital structures: floor of nasal cavity, maxillary

sinus, mandibular canal, mental foramenRadio opaque markers can be used to evaluate

relation of alveolar ridge to existing teeth

Misch’s classification of bone density

INDICATIONS ADVANTAGES LIMITATIONSPERIAPICAL RADIOGRAPHY

Small edentulous spaces, alignment and orientation during surgery

Low radiation dose ; inexpensive

Minimal site evaluation; distortion & magnification

OCCLUSAL RADIOGRAPHY

none Evaluation of pathology

Does not reveal true buccolingual width:Difficulty in positioning

CEPHALOMETRICRADIOGRAPHY

Used with other radiographs for anterior implants

Low magnification;Height/width in anterior region

Limited to midline; reduced sharpness & resolution

PANORAMIC RADIOGRAPHY

Commonly used Initial assessment of vertical bone height;Gross anatomy & pathology evaluation

Distortion; does not demonstrate bone quality

COMPUTED TOMOGRAPHY

Determination of bone density; vital structure location; determination of pathology

Negligible magnification; high contrast image; 3D;Various views

Cost; technique sensitive

Laboratory testsLaboratory testsComplete blood count WBC- 4,000 to 11,000 cells/mm3

RBC- 4-6 million/mm3

Platelet- 1,50,000- 4,00,000cells/mm3

MCV- 80-100 fL MCHC- 32 to 36 g/dL hemoglobin- 11- 16 g/dLProthrombin time- INR (normal range- 0.8 to 1.2)Glycemic control- HbA1c (4 to 6%)Thyroid function tests- T3- 60 to 175 µg/dl T4- 4-11 ng/dl

Conclusion Conclusion The success and predictability of

dental implants have changed philosophy and practice of dentistry.

However, proper pre treatment evaluation, and a treatment plan are imperative for its success.

Reference Reference Contemporary implant dentistry, 3rd ed,

Carl E MischCarranza’s clinical periodontology, 10th ed.Phillips’ science of dental materials, 11th

ed, AnusaviceShenoy VK. Single tooth implants:

Pretreatment considerations and pretreatment evaluation. J Interdiscip Dentistry2012;2:149-157.

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