TOOTH PREPARATION: FULL VENEER ANTERIOR PFM

Principles and Technique of Tooth Preparation of a Maxillary Central Incisor to Receive a Porcelain Fused to Metal Crown

1. TOOTH PREPARATION IN FPD FOR ANTERIOR PFM CROWN DR. AAMIR GODIL DEPARTMENT OF PROSTHODONTICS M.A.R.D.C.

2. PRINCIPLES OF TOOTH PREPARATION The principles of tooth preparation may be divided into three broad categories: Biologic considerations: which affect the health of the oral tissues 2. Mechanical considerations: which affect the integrity and durability of the restoration 3. Esthetic considerations: which affect the appearance of the patient Contemporary fixed prosthodontics. Stephen Rosenstiel, Martin Land, Junhei Fujimoto- 5 th edition (2015)

3. MARGIN GEOMETRY Chamfer Shoulder Sloped Shoulder Knife Edge Feather Edge Radial Shoulder Shoulder with Bevel

4. PORCELAIN FUSED TO METAL CROWN TOOTH PREPARATION FOR INCISOR

5. PFM CROWNS

6. OVERVIEW

7. BIOMECHANICAL CONSIDERATIONS BIOLOGICAL CONSIDERATIONS 1. Prevention of damage Pulp Periodontium 2. Conservative preparation PFM restoration Minimal taper Avoidance of over contour 3. Margin placement and adaptation Supragingival X Subgingival Well flushed 4. Harmonious occlusion and prevention of tooth fracture

8. BIOMECHANICAL CONSIDERATIONS MECHANICAL CONSIDERATIONS 1. Retention form Taper: ~6 degrees Prevention of undercuts Optimal surface area of preparation Retentive luting agent 2. Resistance form Adequate taper and height: width ratio Pinholes/ grooves/ boxes Choice of luting agent 3. Prevention of deformation Adequate tooth preparation Alloy selection: Noble/ base metal Margin placement and geometry

9. BIOMECHANICAL CONSIDERATIONS ESTHETIC CONSIDERATIONS 1. PFM/ all ceramic Compromised esthetics 2. Acrylic facing/ porcelain facing X Less conservative 3. Partial coverage X Not applicable

10. PREPARATION DESIGN

11. MARGIN GEOMETRIES Chamfer Shoulder Shoulder with bevel

12. ARMAMENTARIUM Armamentarium for the PFM preparation Flat ended, tapered: diamond Round ended, tapered: diamond Twelve fluted: carbide Round : diamond Oblong (football): diamond Round wheel (donut): diamond

13. ARMAMENTARIUM

14. OVERVIEW

15. STEPS IN TOOTH PREPARATION Guiding grooves Labial shoulder margin Blending with guiding grooves Labial reduction Palatal reduction

16. WINGED VS WINGLESS PREPARATION The “wingless” variation does not exhibit the defined transition from chamfer margin to shoulder margin. Rather, the shoulder margin gradually narrows toward the lingual side. An even chamfer margin width and a smooth transition between lingual and axial surfaces. The chamfer margin is distinct and blends smoothly into the facial shoulder margin.

17. PUTTY INDEX Facial index Mid-sagittal index

18. DEPTH GROOVES Labial grooves Incisal grooves

19. INCISAL REDUCTION 1.5 – 2.0 mm incisal reduction

20. FACIAL REDUCTION Facial reduction 1.0 – 1.5 mm Proximal lip For breaking adjacent tooth contact

21. LINGUAL REDUCTION: CINGULUM 0.7 mm depth demarcation with round bur Cingulum reduction with wheel bur

22. AXIAL REDUCTION (PROXIMAL) Proximal reduction and rounding off line angles

23. FINISHING Axial and marginal finishing Final preparation

24. ASSESSMENT Assessment of preparation using pre-operative putty index

25. FINAL PREPARATION Schematic representation

26. REFERENCES

27. THANK YOU