RESIN BONDED FPD.pptx

RESIN BONDED FPD-Dr.Ratheesh N

1. RESIN BONDED FPD Dr Ratheesh Senior lecturer Department of Prosthodontics

2. contents Introduction Indications and contraindications Advantages and disadvantages Classification Fabrication Conclusion

3. DEFINITION A Fixed dental prosthesis that is luted to the tooth structures, primarily enamel, which has been etched to provide mechanical retention for the resin cement

4. It is also termed as adhesive bridge First described by Rochette in 1973 Buonocores acid etch technique and Bowne’s resin assisted the development of this concept

5. INDICATIONS 1. Replacement of missing anteriors 2. Abutment with sufficient enamel to etch for retention 3. Splinting periodontally weak teeth

6. 4.Short span bridges 5. Medically compromised patients 6. As a temporary restoration 7. Postorthodontic retention

7. CONTRAINDICATIONS 1. Insufficient occlusal clearence 2.Thin anterior teeth faciolingully 3. Short clinical crown 4. When facial esthetics needs a change

8. 5. Deep vertical overlap 6. Sensitivity to base metal alloys 7. Long span bridges 8. Para functional habits

9. 9. Insufficient enamel available for bonding

10. INDICATIONS CONTRAINDICATIONS Replacement of missing anteriors Abutment with sufficient enamel to etch for retention Short span bridges Splinting periodontally weak teeth Insufficient occlusal clearance Thin anterior teeth faciolingually Short clinical crowns When facial esthetic of teeth require a change

11. INDICATIONS CONTRAINDICATIONS Medically compromised patients As long term temporary restoration in patients with craniofacial anomalies Post orthodontic retention Insufficient enamel available for bonding- caries, restoration, hypoplasia Deep vertical overlap Parafunctional habits Long span bridges Sensitivity to base metal alloys

12. ADVANTAGES DISADVANTAGES Conservation of tooth structure, preparation is confined to enamel Tolerant to tissue with no pulpal trauma and supragingival margin Anesthesia not required Impression making is easy Longevity is in question Technique sensitive Space, contour and alignment correction of abutment is not possible Possibility of overcountouring is high which can lead to increased plaque accumulation

13. ADVANTAGES DISADVANTAGES Provisional restoration are not required Less chair side time Does not require cast alteration or removable dies Reduced cost Rebonding possible Can be used to restore only one tooth Can cause greying in thin tooth Aesthetic is moderate

14. C lassification Mechanical Micromechanical Macromechanical Chemica l

15. Mechanical( R ochette bridge) Developed in 1973 First resin bonded prosthesis Rochette utilized a wing like retainer with multiple flared perforation to provide mechanical retention for resin cement

16. This was used at that time for both anterior and posterior FPD

17. L imitation Perforation weakened the metal retainers The resin in the perforations was exposed to oral fluids, which caused wear and microleakage Retention provided by perforation are limited

18. Micromechanical ( M aryland bridge) Developed by L ivaditis and T hompson at the University of Maryland in 1981 Electrolytic etching was used to provide micromechanical retention to non perforated base metal retainer, bonded by resin cement

19. For etching they used 3.5% solution of nitric acid with a current of 250mA/cm2 for 5min followed by immersion in 18% HCL solution in an ultrasonic cleaner for 10min 10% sulphuric aid in 300mA/cm2 current has been used for etching beryllium containing alloys and a one step technique using sulphuric acid and hydrochloric acid placed in an ultrasonic cleaner for 99sec while current is passed

20. ADVANTAGES Better retention than perforated retainers Highly polished retainers prevented plaque accumulation

21. LIMITATIONS Highly technique sensitive Variable results were reported for etching the same alloy Retention decreased with time

22. Macromechanical VIRGINIA BRIDGE Developed by Moon and Hudgins at university of Virginia in 1983 Utilized macroscopic mechanical retention using lost salt crystal technique

23. PROCEDURE The die is lubricated and sieved cubic salt 150-250 cm3 is sprinkled on the surface leaving out the margins A resin pattern is now constructed over the salt allowing it to get incorporated in the resin The sat is then dissolved by placing the set pattern in an ultrasonic cleaner. This leaves behind voids in the pattern, which is reproduced in the casting. This provides retention

24. ADVANTAGES Procedure can be used with any metal Bonding to metal superior to electrolytic method

25. DISADVANTAGES Thickness of the retainer is increased to allow retentive layer

26. CAST MESH FPD A nylon mesh is placed on the palatal/lingual surface of the abutment dye and the pattern is fabricated over this mesh The mesh gets incorporated and following casting provides retention for resin to metal

27. DISADVANTAGE Adaptation of nylon mesh to cast is not good The wax may flow in between the mesh locking all undercuts

28. Chemical (adhesive bridge) Most commonly used High bond strength Fracture toughness Long term clinical success

29. Modified Bis GMA cement A metal primer is used to bond the resin cement to metal alloys Effective for both noble and base metal alloy

30. Super bond powder - polymer of methyl methacrylate and liquid - methyl methacrylate modified with adhesive 4-META catalyst -tri-n- butylborate

31. Rocatec system Laboratory method of bonding tooth to both noble and base metal alloy Fitting surface is sandblasted with 120mcm alumina Followed by abrasion with a special silicate particle containing alumina which deposits a coating of silica and alumina on alloy suface

32. A saline coupling agent is applied to bond the metal to resin cement There is a risk of contamination of silica treated surface before or during clinical procedure

33. fabrication TOOTH PREPARATION Principles Lingual axial reduction following the anatomic planes Proximal preparation must extend labially just beyond contact dictated by esthetics Should encompass at least 180 degree of tooth

34. Supra-gingival chamfer finish line Occlusal clearance of 0.5 mm where required Resistance can be enhanced by proximal groove boxes Vertical stops or support can be provided by countersink or cigulum rest in anterior abutments and occlusal rest in posteriors

35. Anterior preparation design and sequence

36. Posterior prepration design and sequence

37. Impression and provisionals Similar to any other FPD Elastomeric impression material

38. B onding Prepared tooth surface is cleaned using pumice and water 37% phosphoric acid is used to etch the prepared enamel for 15sec. It is then rinsed and dried Specially formulated composite resin cements are available for bonding resin bonded FPD A metal primer or silane is applied on the fitting surface of the casting

39. A bonding agent or primer is also applied on the prepared enamel surface Resin cement is mixed and placed on the internal surface of retainer The prosthesis is inserted and finger pressure is maintained for 60sec till the initial set excess cement is removed and material is allowed to completely set The occlusion is adjusted and margins are finished and polished

40. C onclusion Resin bonded prosthesis are viable prosthesis n selected situations. They should receive the same attention to detail as conventional FPD for long term success . Patient selection is vitally important and tooth preparation or enamel activation is mandatory.

41. Thank you