LAMINATES VENEERS.pptx
Download as PPTX, PDF3 likes2,592 views
This document discusses laminate veneers, including: 1. Laminate veneers have evolved over decades to become a popular aesthetic restoration, providing a conservative alternative to full coverage restorations. 2. They involve bonding thin ceramic restorations to etched tooth structure to restore the facial and proximal surfaces. 3. Indications include masking diastemas, discoloration, enamel defects, malpositioned teeth, while contraindications include insufficient tooth structure or parafunctional habits.
LAMINATES VENEERS.pptx
- 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 • Impossible 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: 1. Etching of enamel by Buonocore (1955) 2. Bowen’s BIS-GMA resins (1960s) 3. Ceramic etching and bonding by Rochette (1973).
- 9. INDICATIONS • 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 1) 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) Proximal 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
Editor's Notes
- #5: It is the prosthetic treatment that consists of replacing the visible portion of the dental enamel with a ceramic substitute, intimately bonded to the tooth surface, yielding optical, mechanical and biological properties closely resembling those of the natural enamel
- #7: With the earliest motion pictures were produced, the films were so jumpy it was In the late 1920s, the talkies arrived. Combined with improved filming and projecting techniques, which made minor details more visible,
- #8: first used thin resin facings and then air fired porcelain facings to
- #16: thickness of tooth, need for increasing tooth length and occlusion determine whether type I or II is used.
- #41: The silane creates a chemical bond between composite cement and ceramic
- #43: Composite bonding agent is applied on the tooth surface and is not light-cured now