LAMINATES VENEERS.pptx

Dr Shrimant Raman (Prosthodontics)

1. LAMINATE VENEERS (PART-I) DR SHRIMANT RAMAN DEPARTMENT OF PROSTHODONTICS

2. INTRODUCTION The dental profession is faced with specific esthetic demands and a rapid evolution of new but unproven techniques Although the direct bonding of porcelain veneers is relatively new, reports of success warrant its inclusion as a restorative treatment.

3. Laminate veneers have evolved over the last several decades to become one of aesthetic dentistry’s most popular restorations. It is a conservative alternative to full coverage for improving the appearance of an anterior tooth

4. DEFINITION Veneer: A thin sheet of material usually used as a finish (GPT8). Veneer is a tooth-coloured material that is applied to restore localized or generalized defects and intrinsic stains.

5. Laminating: Constructing a veneer and bonding it to etched tooth structure. Porcelain laminate veneer: A thin bonded ceramic restoration that restores the facial surface and part of the proximal surfaces of teeth requiring aesthetic restoration (GPT).

6. HISTORY I mpossible to see the fine facial features, and close up sequence were rare Hollywood film makers experienced a dental dilemma. Thus, it became necessary for movie stars to have glamorous smiles Thus, necessity led to invention.

7. In 1930s Dr Charles Pincus create the ‘Hollywood smile’ for American actors. He used denture adhesive to hold the veneer in place. In the 1970s, preformed plastic laminates were bonded to the teeth using composite resin, but bonding to the plastic was poor along with colour instability.

8. The evolution of the modern ceramic laminate was assisted by the following discoveries: Etching of enamel by Buonocore (1955) Bowen’s BIS-GMA resins (1960s) Ceramic etching and bonding by Rochette (1973).

9. I NDICATIONS Diastema Extreme discolouration Enamel defects Tooth fracture Malpositioned teeth and abnormalities of shape Abraded and eroded facial surfaces Attrition

10. CONTRAINDICATIONS Endodontically treated teeth Parafunctional habits like bruxism Insufficient coronal tooth structure Actively erupting teeth Severe periodontal involvement and crowding

11. Advantages Disadvantages Minimally invasive – conservative Excellent colour and light transmission – good aesthetics High colour stability Good tissue response Excellent durability – good strength, wear resistance and no fluid absorption Speed and simplicity Tooth preparation, however minimal, is required Cementation is time-consuming and technique sensitive Fragile – may fracture if improperly handled during try-in or cementation Proper selection of underlying cement is critical for success Difficult to repair Cost

12. Materials used as veneers in dentistry: Chair side composite Processed composite Porcelain Pressed ceramics

13. Types : Partial veneer – Localized defects Full veneer – Generalized defects Techniques : Direct – composite, same day, time- consuming Indirect – 2 appointments, better esthetics, best for multiple teeth, long life for porcelain

14. SHADE SELECTION This should be done at the beginning , during the consultation or treatment planning appointment. It has to be done when the teeth have not been dried out for any period of time. It is done under a colour corrected light or outside in daylight. It is best for a ceramist to make an individualized shade guide and not by conventional vita shade guide

15. TOOTH PREPARATION TYPES TYPE I - contact lens type: Does not cover the incisal edge Type II – classic or conventional type: Most commonly used; covers the incisal edge and terminates lingually Type III – wrap-around or three-fourth type

16. ARMAMENTARIUM A diamond depth cutter with three 2 mm diameter wheels mounted on a 1.0 mm diameter noncutting shaft. Produces a depth cut of 0.5 mm. A diamond depth cutter with a wheel diameter of 1.6 mm produces a depth cut of 0.3 mm.

17. Round bur (No. 1) Round-end tapering diamond (medium and fine grit) Finishing diamond and burs Airotor handpiece

18. PROCEDURE Labial reduction : 1. Depth cuts 2 . Reducing remaining enamel DEPTH CUT ALONG GINGIVAL MARGINS WITH A NO. 1 ROUND BUR DEPTH CUT EXTENDED PROXIMALLY AND INCISALLY DEPTH CUTS USING ONLY ROUND BUR

19. DEPTH CUT ALONG CENTRE OF TOOTH

20. TWO DEPTH CUTS PLACED MESIODISTALLY

21. DIRECTION OF INSTRUMENT TO REDUCE REMAINING ENAMEL

22. DEPTH CUTS DIAMOND DEPTH CUTTER DEPTH CUTS WITH DEPTH CUTTER DIAMOND

23. DIRECTION OF INSTRUMENT TO REDUCE REMAINING ENAMEL

24. 2) P roximal reduction : Depth can often be as great as 0.8–1 mm, since the enamel layer is thick towards proximal surface PROXIMAL REDUCTION SHORT OF BREAKING CONTACT

25. Reasons to preserve contact area : It is an anatomical feature that is extremely difficult to reproduce It prevents displacement of the tooth between the preparation and placement appointment if no provisional restorations are planned . Post-insertion oral care is easier. Simplifies try-in – no need to adjust the contact. Simplifies bonding and finishing.

26. 3) Sulcular extension Routinely the margins are placed supra gingivally. When discoloration is excessive, the margins are extended sub gingivally. A rounded 0.3 mm chamfer serves as an ideal margin for ceramic laminate veneer SUPRAGINGIVAL MARGIN PLACEMENT.

27. Advantages of supragingival margin : Increased areas of enamel in the preparation . Simplified moisture control. Visual confirmation of marginal fit. Margins are accessible for finishing and polishing . Access to margins for routine maintenance and dental hygiene procedure.

28. Advantages of chamfer finish line : Conservative, distinct. Provides increased bulk of porcelain giving adequate strength, avoids over contouring. Good marginal seal. Accuracy of fit – veneer is easily inserted at try-in and final placement. For type I preparations, the tooth reduction ends here. For type II preparations, incisal and lingual reductions are necessary.

29. 4) Incisal reduction INCISAL DEPTH CUTS INCISAL REDUCTION

30. Indications for incisal coverage : The incisal thickness is too thin to support the veneer. A lengthening of the incisal edge of 1–2 mm is desired. Facio-incisal margin is visible and unaesthetic. Incisal enamel is structurally compromised. The incisal edge is subject to functional stress.

31. 5) Lingual reduction LINGUAL REDUCTION

32. SOFT TISSUE MANAGEMENT Gingival retraction can be done just prior to tooth preparation when the finish line is placed 0.5 mm sub gingivally It can also be done prior to impression making During cementation, placement of retraction cord prevents the contamination of the cervical margins with sulcular fluid and facilitates the finishing of the cervical margin

33. Impression procedure Light body syringed around the preparation. Putty mixed and loaded onto stock tray.

34. Tray placed over the syringed light body Single impression made using double mix

35. Cementation Initial veneer inspection The veneer is placed on the cast and assessed for the following: • Imperfections • Individual fit • Collective fit (for multiple veneers ) • Veneer colour

36. Preparation of site The prepared teeth are isolated, provisional removed and cleaned with pumice Prepared teeth cleaned with pumice

37. Try-in The veneers are then tried-in the patient’s mouth. They are checked for: • Individual fit • Collective fit • Colour Water-soluble glycerin, transparent silicones and colour keyed try-in pastes can be used to attach the laminate to the tooth during try-in.

38. Bonding Bonding involves the following procedures : • Preparation of veneer • Preparation of tooth • Luting

39. Preparation of veneer Cleaning of the veneer with a solvent such as acetone Etched with 10%–15% hydrofluoric acid for 30 s to 1 min Some clinicians tend to get the veneer etched by the laboratory; this is not recommended as the etched surface may get contaminated during handling and try-in procedures. Fitting surface filled with ceramic etchant

40. A normal composite bonding agent is finally applied to the fitting surface at the same time when the tooth surface is also bonded. It is not light cured. Application of Silane coupling agent

41. Preparation of tooth The prepared teeth are pumiced again to remove any try-in paste or cement. Isolation with soft metal bands Etching with phosphoric acid

42. Application of bonding agent on tooth

43. LUTING The cement of choice for luting ceramic laminate veneers is resin cement Cement mixed Cement applied on fitting surface and spread evenly

44. Initially light cured for 5 s Final curing for 45–60 s Excess removed

45. FINISHING Margins finished with fine grit diamonds Finishing strips are used for proximal surfaces Discs are used for final finishing

46. MAINTENANCE For 72–96 h following insertion, patients should avoid highly coloured foods, tea or coffee, hard food and extreme temperatures. Routine scaling should be done at least every 4 months, ultrasonic scalers may be avoided. Abrasive and highly fluoridated tooth paste should be avoided. Excessive biting forces and nail biting and pencil chewing habits should be avoided. Soft acrylic mouth guard can be used during contact sports.

47. CAUSES OF FAILURE OF CERAMIC LAMINATE VENEERS

48. THANK YOU