case selection annd preparation of porcelai veneers

1. PORCELAIN LAMINATE.
VENEERS

2. INTRODUCTION
• A thin bonded ceramic restoration that restores the facial surface and part of
proximal surfaces of teeth requiring aesthetic restoration

3. HISTORY
HOLLY WOOD SMILE

4. INDICATIONS
• MILDTO MODERATE
DISCOLOURATION
• TETRACYCLINE STAINING
• FLOUROSIS
• ANY DISCVOLOURATION
UNRESPONSIBETO BLEACHING

5. • ENAMEL DEFECTS, SMALL
CRACKS,TRAUMA , HYPOPLASIA
• DIASTEMA
• ABNORMALITIES OFTEETH IN
SIZE AND SHAPE , PEG LATERALS

6. • ATTRITIONS
• ROOT EXPOSURES
• TOOTHJ FRACTURE OF INCISAL ONETHIRD
• Restoring incisal guidance of mandibular anterior teeth

8. CONTRAINDICATIONS
• GROSSLY CARIOUS
• EXTENSIVE RESTORATIONS
• FRACTURE OF MORETHAN HALF OFTOOTH
• DENTINOGENESIS IMPERECTA

9. CONTRAINDICATIONS
• ACTIVELY ERUPTINGTEETH
• BRUXISM
• CLENCHING
• POOR ORAL HYGIENE

10. CONTRAINDICATIONS
• SEVERE CROWDING
• PERIODONTAL DISEASE
• ENDODONTICALLY TREATEDTOOTH

11. DIASTEMA CLOSURE & FLOROSIS

13. STEP BY STEP PROCEDURE OF PREPARATION &
CEMENTATAION

14. DIAGNOSIS & TREATMENT PLANNING

15. 1. CONSTRUCTION OF PUTTY INDEX
DEPTH CUTS 0.5MM

16. PREPARATION DESIGNS

17. 2. CONSTRUCTION OF PUTTY INDEX
DEPTH CUTS 0.5MM
• Make a series of depth holes with a round bur / depth cutting
bur to avoid penetrating abnormally thin enamel.The amount of
reduction required depends somewhat on the extent of
discoloration.

18. 3. MARGIN DESIGN
Place the “long chamfer” margin. This
design has an obtuse cavosurface angle,
which exposes the enamel prism ends
at the margin for better etching.The
margin should closely follow the gingival
crest so that all dis- colored enamel
prisms are veneered without undue
encroachment on the gingival sulcus.

19. PRESERVE THE CONTACT AREA
• Wherever
possible, place
the preparation
margin labial to
the proximal
contact area to
preserve it in
enamel.

20. SYSTEMS OF LAMINATEVENEERS

21. CEMENTATION OF PORCELAINVENEERS

22. CEMENTATION PROCEDURE FOR PORCELAIN
VENEERS
These restorations rely on resin bonding for retention and
strength.The cementation steps are critical to the restoration’s
success; careless handling of the resin luting agent may be a key
factor in their prognosis.

24. 1. SHADE SELECTION
• Using try-in paste
• Before the actual cementing step, veneers must be tried-in.
• Both the patient and the dentist must be satisfied with the aesthetic result. It is also
necessary to check:
• the precision of the preparation margin;
• the proper location of the point of contact;
• the contacts in maximum intercuspation, protrusion and laterality.

25. PRETREATMENT OF INNER SURFACE OFVENEER
The first step of cementing is the proper
preparation of the inner surface of the veneer to
be cemented.
The purpose of pretreatment is to make the inner
surface of the veneer fit for a bonding
procedure.
Glass-matrix ceramics like lithium disilicate
and feldspathic ceramic must be pretreated
by etching with hydrofluoric acid, which is able
to dissolve the glass matrix and expose the
crystalline structure.

27. PRETREATMENT OF INNER SURFACE OFVENEER

28. PRETREATMENT OF INNER SURFACE OFVENEER

29. PRETREATMENT OF INNER SURFACE OFVENEER
Once etching is complete, a coupling agent, such as
silane, is applied to bind the organic components
with the inorganic ones, to create a chemical bond
between the composite resins and the inorganic
glass matrices.

30. • Zirconia, on the other hand, cannot be etched, because it is not vitreous.The most
effective pre-treatment for zirconia appears to be technique involving
sandblasting with silica-coated aluminium particles at a pressure of 1.8-2.8 bar and
subsequently, the use of a primer containing the monomer MDP would appear to be
effective.

31. 3) ISOLATION AND ETCHINGTECHNIQUES
• The preparations are thoroughly cleaned; the
• clinician makes sure all interim luting agent is removed.
Once the teeth have been isolated, it is possible to perform etching.This is usually done using
35% phosphoric acid.
After this, depending on the bonding technique chosen, the primer and bonding agent are
applied and, once the bonding agent has been evenly distributed using a jet of air, it is cured.
Usually, the bonding agent is applied to the surface of both the tooth and the veneer.

32. TOOTH IS THOROUGHLY CLEANED

33. ACID ETCHING

36. POSITIONINGTHE RESIN-BASED LUTING
CEMENT INSIDETHEVENEER
• The last step is to position the resin-based luting cement of the chosen colour inside
the veneer.The veneer is positioned by applying light pressure, watching the excess luting
cement ooze from the preparation margin.

37. FINAL CURING
Once the position and proper fit of the veneer have been
ascertained, and once the excess luting cement has been
removed, it is possible to carry out final curing.
•

38. ADVANTAGES & DISADVANTAGES
• QUESTION