Bevels in Dental Restorations

Any abrupt incline between the two surfaces of a prepared tooth or between the cavity wall and the cavo-surface margins in the prepared cavity

1. R.K.HARITHA IV Year CDCRI BEVEL

2. CONTENT Introduction Definition Classification Advantages & disadvantages Bevels in Cast restoration Composites Veneers/Laminates

3. INTRODUCTION Occlusal cavo -surface margin (40°) Gingival cavosurface margin (30°) Remove unsupported enamel Prevent marginal leakage Ref: Sturdevants Art and Science of Operative dentistry, South Asian edition

4. DEFINITION “ Any abrupt incline between the two surfaces of a prepared tooth or between the cavity wall and the cavo -surface margins in the prepared cavity.” Ref: Sturdevant’s Art and Science of Operative dentistry

5. Based on shape and tissue surface involved Based on the surface they are placed on CLASSIFICATION

6. Based on the surface they are placed on Based on shape and tissue surface involved Partial/Ultra short bevel Short bevel Long bevel Full bevel Counter bevel Reverse/ Minnesota bevel Gingival bevel Hollow ground bevel Occlusal bevel – Functional cusp bevel

7. BASED ON SHAPE AND TISSUE SURFACE INVOLVED Not more than 2/3 rd of enamel involved Trim unsupported enamel. PARTIAL BEVEL Ref: Ramya Raghu Clinical Operative Dentistry Principles and practice, 2 nd edition

8. BASED ON SHAPE AND TISSUE SURFACE INVOLVED Involves the entire enamel wall but not dentin Used in Cast gold inlay cavities, composites, veneers SHORT BEVEL

9. Involves entire enamel and half the dentinal wall Internal boxed up resistance and retention is preserved. Long BEVEL BASED ON SHAPE AND TISSUE SURFACE INVOLVED

10. Involves entire enamel wall and dentinal wall of the preparation Used when others are impossible full BEVEL BASED ON SHAPE AND TISSUE SURFACE INVOLVED

11. Capping cusps Placed towards the axio - gingival line angle. Prevents rotational forces . counter BEVEL reverse BEVEL BASED ON SHAPE AND TISSUE SURFACE INVOLVED

12. 2. BASED ON THE SURAFACE THEY ARE PLACED ON GINGIVAL BEVEL: Remove unsupported enamel 30 degree gingival margin burnishable Lap sliding fit – improve the fit of casting Used for Inlay preparation HOLLOW GROUND (CONCAVE) BEVEL: More space for bulk of cast metal

13. OCCLUSAL BEVEL: Junction of occlusal 1/3 rd and pulpal 2/3rd Satisfy the requirements of ideal cavity walls Flexible extensions Minimum tooth involvement without sacrificing resistance and retention Obtuse angle margins – bulkiest and strongest marginal configuration of tooth anatomy + Acute angled marginal cast alloys burnishable FUNCTIONAL CUSP BEVEL: Wide bevel in functional cusp adequate bulk in heavy occlusal contact Ref: Ramya Raghu Clinical Operative Dentistry Principles and practice, 2 nd edition

14. ADVANTAGES DISADVANTAGES Better esthetics Reduced marginal leakage Better fit Stronger adhesion/bonding Remove unsupported enamel Tooth structure loss ADVANTAGES & DISADVANTAGES

15. BEVELS IN CAST RESTORATIONS Armamentarium: No. 8862 – slender, flame shaped, fine grit diamond instrument TYPE OF BEVEL TYPE OF CAST RESTORATION SHORT BEVEL Cast Gold Restoration INVERTED BEVEL (improve esthetics) Metal Ceramic Crowns REVERSE BEVEL Cast Restoration FUNCTIONAL CUSP BEVEL Metal Crowns Ref: Vimal K.Sikri Textbook of Operative Dentistry, 4 th edition, CBS publishers

16. BEVELS IN PARTIAL VENEERS/ LAMINATES SHORT BEVEL Ref: Vimal K.Sikri Textbook of Operative Dentistry, 4 th edition, CBS publishers

17. BEVELS IN COMPOSITE RESTORATIONS TYPES OF COMPOSITE RESTORATION TYPES OF BEVEL CLASS I Cavosurface margin 90 degree adv: decreased marginal breakdown and ditching, disadv : marginal staining CLASS II Short bevel; no bevel in occlusal CLASS III & IV Lingual approach – no bevel; Labial approach – 45 degree bevel CLASS V Short bevel (colour matching) CLASS VI No bevel Ref: Vimal K.Sikri Textbook of Operative Dentistry, 4 th edition, CBS publishers

18. THANK YOU!! APRIL 95 APRIL 00 NOVEMBER 01 OCTOBER 03 AUGUST 04 AUGUST 13 REFERENCES: Harold O Heymann , Sturdevants Art and Science of Operative dentistry, South Asian edition Vimal K.Sikri Textbook of Operative Dentistry, 4 th edition, CBS publishers Ramya Raghu Clinical Operative Dentistry Principles and practice, 2 nd edition,EMEES