A conservative smile makeover utilizing both a minimally...

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52 DENTAL TEAMWORK Vol.6-No.5 - May 2013 A conservative smile makeover utilizing both a minimally invasive and non-invasive prep-less porcelain veneer technique. Dr. Snyder I n the past decade cosmetic dentistry has changed dramatically with the ability to utilize newer more durable ceramic restorations to alter the appearance of one’s smile. In the 90’s the advent of pressed ceramics allowed for veneers to be fabricated from a stronger material but more aggressive preparations were necessary at approximately eight tenths of a millimeter or more necessitating dentin bonding. The original feldspathic porcelain veneering technique described in the 80’s utilized about half a millimeter of tooth reduction along with enamel bonding to achieve high bond strengths and great success. By comparison the more extensive tooth reduction that came with pressed ceramics utilized more dentin bond which at the time offered lower bond strengths compared to enamel and restorations often had a reduced longevity. 1 Thinner and more aesthetically appealing restorations have come back Fig. 1 Fig. 2 Fig. 3

Transcript of A conservative smile makeover utilizing both a minimally...

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52 DENTAL TEAMWORK Vol.6-No.5 - May 2013

A conservative smile makeoverutilizing both a minimallyinvasive and non-invasiveprep-less porcelain veneertechnique.Dr. Snyder

In the past decade cosmetic dentistryhas changed dramatically with theability to utilize newer more durable

ceramic restorations to alter theappearance of one’s smile. In the 90’sthe advent of pressed ceramics allowedfor veneers to be fabricated from astronger material but more aggressivepreparations were necessary at

approximately eight tenths of amillimeter or more necessitating dentinbonding. The original feldspathicporcelain veneering technique describedin the 80’s utilized about half amillimeter of tooth reduction alongwith enamel bonding to achieve highbond strengths and great success. Bycomparison the more extensive tooth

reduction that came with pressedceramics utilized more dentin bondwhich at the time offered lower bondstrengths compared to enamel andrestorations often had a reducedlongevity.1

Thinner and more aestheticallyappealing restorations have come back

Fig. 1 Fig. 2 Fig. 3

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into popularity in more recent yearswith the introduction of lithiumdisilicate restorations. These modernhigh strength ceramics can be utilizedto fabricate conservative veneers that areapproximately three tenths of amillimeter in thickness just likefeldspathic porcelains. Furtheradvances in the lithium disilicatechemistry have also createdimprovements in both translucency andaesthetics. The material can be utilizedfor very thin restorations with life likecharacteristics very much liketraditional stacked/feldspathic porcelainveneers yet having substantially highermaterial strength properties. Thecurrent ability to alter the appearance ofteeth while maintaining enamel toadhere to and utilizing strong pressedceramics or traditional feldspathic

porcelain is as good as or better thanever before. The continued growth insmile makeovers and porcelain veneerscontinues to be an area of interest aspublic awareness grows from morevisibility in movies, television and othermedia. Based on aesthetics, strengthand technique there are many optionsavailable to alter our patientsappearance, but more importantly thatanyone can offer the procedure whereapplicable with minimal to no damageof the tooth structure. Through propertraining and the use of talentedtechnicians we can make incrediblechanges in a patient’s appearance andrecreate beautiful, natural smiles toenhance their lives far better than theycould ever imagine while beingminimally invasive.

In this case a patient presents postorthodontic therapy with the desire toclose spaces, change the shape andremove unsightly decalcifications on theanterior teeth. The patient presentedwith no periodontal disease and a stableposterior occlusion, but has minimalcanine guidance. The treatment planwould be to have the patient’s teethcleaned followed by impressions tocreate four sets of diagnostic models.The first set would remain untoucheddocumenting how the case originallypresented. The second set would beused to fabricate custom whiteningtrays for the patient to use at homeprior to starting the case while thediagnostic waxup was being fabricated.The third set of models would be to useas a practice preparation model wheretesting of the hypothetical veneer

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design takes place. The fourth set ofmodels would be sent to the laboratoryfor a diagnostic waxup where themodels would be waxed to idealcontours (while taking into account thepatient’s desired appearance) so that jigsand reduction guides could befabricated.

There are many ways to work up acosmetic case diagnosis and treatmentplan. Photographs of the case are veryimportant to the diagnostic process inevaluating shapes, color and overallappearance in relation to the face.Various templates and smile designbooks can assist in development anddiscussion with the patient and ceramistas to the desired final appearance of therestorations. Additionally digitalphotographs can be measured andevaluated for symmetry and proportionwhere modifications, possible treatmentprocedures and outcomes can behypothesized and created. Outlines ofvarious teeth shapes can be overlaid

onto the existing dentition digitallywhereby the aesthetics and positions ofteeth and gums can be evaluated morethoroughly by the dentist, specialists,technicians and the patient. Ultimatelya diagnostic wax-up needs to be createdby using the various forms of input onshape, texture, color, translucency andeffects.2 The diagnostic wax-up, uponapproval from the patient, is consideredthe final treatment plan and can thenbe used to fabricate a template to createan actual mockup on the patient of thefinal shape/appearance for furtherevaluation and verification. In this casethe maxillary incisors were in afavorable position facially and addingan additional layer of porcelain wasdetermined to position the facialsurfaces out further than what would beaesthetically pleasing. These teethwould need minimum reduction toresurface the facial aesthetics and add tothe incisal edges. The canines weredetermined to be deficient bilaterallyfrom the center line of the tooth to the

mesial contact along with the incisaledge needing to be lengthened.

Based on the diagnostic wax-up andthe preparation designs attempted onthe diagnostic models the dentist andceramist can determine the type ofmaterial to be utilized and anyunforeseen problems or hypotheticalsituations can be discussed prior tostarting the case. Feldspathic porcelainwhich has a flexural strength ofapproximately 80 mpa can be usedwhen very minimal porcelain isextended off of tooth structure. Leucitebased ceramics offer about 125-180mpa. Lithium disilicate ceramics have aflexural strength of approximately 360-400 mpa and are ideal for conservativeveneers or ones that require morestrength when lengthening teeth orreplacing larger amounts ofunsupported tooth structure.

The first step in this case was to havethe patient’s teeth cleaned and

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polished.(Fig 1-6) Next we had herwhiten her teeth at home using thecustom fabricated whitening trays untilshe achieved a plateau in approximately10-14 days. The color selection needsto be taken approximately 10-14 daysafter whitening to allow enough timefor the color to stabilize. Furthermoreno adhesive dentistry should beperformed on teeth for two weeks afterwhitening as bond strengths may becompromised from the residualcomponents.3

While the patient is whitening fortwo weeks the diagnostic models (Fig 7)

are being waxed to ideal shapes basedon input from the patient as well as adigital mockup.4 The final diagnosticwax-up was presented to the patientduring the two week whitening follow-up.(Fig 8) Based on the patient’sapproval we will receive anauthorization signature to moveforward with the case using the wax-upas a template by the patient so that wecould then fabricate depth reductionguides, a beadline provisional template,custom impression tray and assortedjigs for the master ceramist.

Local anesthetic (2 carpules 2%Lidocaine w/ 1:100,000 epi) was given.Prior to preparing the teeth aperiodontal probe is used to sound tobone anywhere that an interproximalcontact needs to be created or a gingivalembrasure black triangle needs to beclosed. This will help determine wherethe final contact point will need to bein the restoration to have the gingivaltissues fill in the area such that gingivalblack triangles can be eliminated.5 Thefour maxillary incisors were next to beprepared for veneers. The first step is tocut depth grooves so that minimal yet

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ideal tooth structure can be removed.All of this should have beenpredetermined as to how muchreduction would be necessary prior tothe preparation appointment bypracticing on one of the four sets ofdiagnostic models of the patient’sdentition. Using specially designeddepth cutting burs that offer tenth of amillimeter increment depth cuts (LascoCorporation) followed by diamondburs from the Aesthetic DentalDesigns® bur kit (Brasseler USA) in ane-Stasis SLM electric handpiece(SciCan) the teeth would be reduced toideal depths. (Fig 9-11) #00 retractioncord (Ultradent Products Inc) wasplaced on all six teeth with noastringents. The gingival margins werethen refined on the maxillary incisorswith a sonic handpiece and diamondcoated inserts (Komet USA).6 Thecanines had no preparation done tothem as the deficient areas already hadadequate space that would be filled inwith partial coverage veneers.Photographs were taken to document

the prepared tooth shade for thelaboratory. Impressions were takenwith a vinyl polyether siliconeimpression material (EXA’lence, GCAmerica) in a customized stock HeatWave impression tray (Clinician’sChoice).7 (Fig 12) A wax bite (DelarCorp) and earbow (SAM 3, GreatLakes Prosthodontics) were used alongwith shimstock (Almore Corp) to beable to mount the final models andmaintain the same occlusion. Theprovisionals were then fabricated from abeadline over impression of thediagnostic wax-up using a polyvinylsiloxane (Template, Clinician’sChoice).8 The teeth were treated withtublicid red (Global Dental) prior toplacement of the Structur 3 temporaryacrylic shade B1 (VOCO). Theprovisional restorations were locked onmechanically and hence did not needtemporary cement. The minimal flashof acrylic was due to the excellentadaptation that a beadline provisionaltemplate imparts when used foraesthetic cases. The restorations needed

to just be wiped with an alcohol gauzeto remove the minimal oxygeninhibition layer. (Fig. 13-14)

At the next visit local anesthetic (2carpules 2% Lidocaine w/ 1:100,000epi) was given followed by removal ofthe temporaries. The teeth werecleaned with a Crystal Air heliabrasionunit (CrystalMark Dental Systems, Inc.Glendale, CA.) taking care to avoidcontact with the gingival tissues. Theveneers were evaluated as to shape,color, texture, margins and contacts onthe models. (FIG L1-3) The veneerswere silanated prior to try-in withporcelain prime / bis-silane (BiscoCorporation). A translucent watersoluble try-in gel (Choice 2 Bisco) wasused so the restorations could beevaluated for fit, occlusion andesthetics. The restorations wereevaluated by the patient and uponapproval a signature was received toauthorize cementation. The restorationswere steam cleaned and the teeth wererinsed thoroughly to remove any water

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soluble try-in paste. The veneers werethen redundantly silanated and placedunder a heating element briefly andallowed to dry. Preparations in enamelhave a better longevity for manyreasons, however the most substantialone is that bonding to dentin withresins can have a 30-40% decrease inmicrotensile bond strengths in as littleas 6 to 12 months.9-13 The teeth wereisolated and etched followed by AllBond 3 adhesive and translucentChoice 2 light cured resin cement(Bisco Corporation) were used per themanufacturer’s instructions. Themajority of the excess resin cement wasremoved leaving only a small amounton the margins. The restorations were

cured with a Valo LED curing light(Ultradent Corporation). Excessmaterial was then cleaned off withtungsten carbide carvers (HuFriedy)and the contacts were flossed. Leaving asmall amount of excess resin allows forcertainty of complete curing withouthaving an air inhibition layer on amargin in addition to avoiding having amargin that is not sealed completely.The final restorations having beencleaned, contacts checked and anyexcess resin on the margins beenremoved were then evaluated.(Fig 15-23) Occlusion and excursives werethen verified with TrollFoil (TrollDental) and shimstock (Almore). (Fig24-26) The patient returned a few

weeks later for post-operative evaluationand a clear overlay retainer.

This case highlights the importanceof recognizing that where deficiencies intooth structure, positions or length areinvolved traditional feldspathicporcelain can be used to recreate idealshapes, color, texture and function.When higher strength properties arerequired the modern high strengthlithium disilicate ceramics can beutilized in the same fashion tocompensate and replace the deficienttooth space with a non-invasive preplessveneer technique. However where teethare already in a favorable facial position,minimally invasive preparation

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Fig. 22 Fig. 23

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techniques that maintain enamel arestill necessary to allow for adequatespace for beautiful ceramics and idealtooth shape.14

References1. Radz, G. Porcelain Laminate Veneer

Therapy Ultra-thin veneer optionsusing a no-prep or partial-prepphilosophy. Inside Dent. 2010;6(4).

2. Coachman C, Calamita M. DigitalSmile Design: A Tool for TreatmentPlanning and Communication inEsthetic Dentistry. QDT 2012,1-9.

3. Haywood VB. Tooth Whitening:Indications and outcomes ofNightguard Vital Bleaching. HanoverPark, Il: Quintessence PublishingCompany Inc; 2007

4. Okuda, W. Creating facial harmony

with cosmetic dentistry. CurrentOpinion in Cosmetic Dent, 1997; Vol4:p69-75.

5. Tarnow DP, Magner AW, Fletcher P.The effect of the distance from thecontact point to the crest of the boneon the presence or absence of theinterproximal dental papilla. JPeriodotol. 1992;63(12):995-996.

6. Massironi D, Pascetta R, Romeo G.Precision In Dental Esthetics.Repositioning and Completing theFinish Line with OscillatingInstruments. Quintessence,152-173,2007.

7. Snyder, T. Using technology to createthe perfect impression. DentalProducts Report. 2013;47(2): 96-102.

8. Snyder, T. Bead Line VeneerProvisional Restorations. PPAD,2009;21(3):E1-E7.

9. Pashley, D.H., et al., State of the art

etch-and-rinse adhesives. Dent Mat.2011. 27(1):p1-16.

10.Pashley DH, Tay FR, Imazato S. Howto increase the durability of resin-dentin bonds. Compend Contin EducDent. 2011 Sep;32(7):60-4, 66.

11.DeMunck, J., et al., A critical review ofthe durability of adhesion to toothtissue: methods and results. J Dent Res,2005. 84(2):p118-132.

12.Zhang, S.C., Kern M. The role of host-derived dentinal matrixmetalloproteinase in reducing dentinbonding of resin adhesives. Int J OralSci, 2009.1(4):p163-176.

13.DeMunck, J. et al., Inhibition ofenzymatic degradation of adhesive-dentin interfaces. J Dent Res, 2009.88(12):p.1101-6.

14.Tada H, Snyder T. Masterpiece Theory& Practice – Bleach. QDT Art &Practice. March 2013(38)3;91-98.

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