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resinbondedfixedpartialdbbbbhhhenture.pptx
- 1. Department of Prosthodontics ResinBonded Fixed Partial Denture facebook.com/notesdental
- 2. Why resin-bonded FPD? • Conventional FPD’s requires abutment preparation which leads to destruction of adjacent teeth. • Various solution tried for this problem but not of much result oriented – Inlay retainer – Cantilever FPD – loss of PDL support of abutment teeth – Unilateral RPD – lack of retention, stablity and risk of aspirated if dislodged facebook.com/notesdental
- 3. Development of Acidetching of enamel • Buonocore in 1955 • Less destructive means of attaching FPD’s • Ibsen - attachment of an acrylic resin pontic to an unprepared tooth using a composite bonding resin facebook.com/notesdental
- 4. Classification of RBFPD facebook.com/notesdental •Classified on the basis progression of development: – Rochette bridge – Maryland bridge – Cast Mesh – Virginia bridges
- 5. Rochette bridge • wing-like retainers, •with funnel-shaped perforations through them to enhance resin retention • combined mechanical retention with a silane coupling agent to produce adhesion to the metal facebook.com/notesdental
- 6. Disadvantage • Weakening ofthe metal retainer by the perforations • Limited adhesion of the metal provided by the perforations • Wear of composite resin • Thick lingual retainers • Plaque accumlation • 50% fail in about 110 months facebook.com/notesdental
- 7. Maryland Bridge • etched-metalprosthesis • Done in either two step process or one step process – equally retentive. • advantages over the caste perforated restorations – resin-to-etched metal bond can be substantially stronger than the resin-to-etched enamel – The retainers can be thinner and still resist flexing – oral surface of the cast retainers is highly polished and resists plaque accumulation facebook.com/notesdental
- 8. Two-step process facebook.com/notesdental • Livaditisand Thompson • electrochemical pit corroding technique • 1st step – 3.5 % Nitric acid at 250 mA/sq cm (current) for 5 min – non-beryllium-containing nickel- chromium alloy – 10% sulfuric acid at 300 mA/cm2 (current) for 5 min - beryllium nickel-chromium alloy • 2nd step : 18% HCl for 10 minutes in an ultrasonic cleaner bath
- 9. 1-step facebook.com/notesdental • McLaughlin • fastertechnique • combined solution of sulfuric and hydrochloric acids placed in an activated ultrasonic cleaner for 99 seconds passing electrical current.
- 10. Disadvantage facebook.com/notesdental • Technique sensitive •Lab dependent • Varies with metal type • Prone to contamination • Cannot be done with noble metal alloys
- 11. Chemical Etching facebook.com/notesdental • Livaditis •a non electrolytic technique for etching a nickel-chromium beryllium alloy • Placed in an etching solution for one hour in a water bath at 70 degrees centigrade • Doukoudakis proposed the use of a stable aqua regia gel • Advantage – no special equipment
- 12. Modification facebook.com/notesdental • Retainers coatedwith pyrolized silane (Silicoater, Kulzer,Irvine,CA) – more retentive – 47% to 104% : only etching – 23% to 124% : composite-to-metal bonding systems • Air abrading metal with 250-μm abrasive increases bonding strength remarkably when used in conjunction with silane.
- 13. Cast Mesh FPD •Non etching method after casting • Produce roughness before the alloy is cast, or use a. • net-like nylon mesh – lingual surfaces of the abutment teeth on the working cast • Covered by and incorporated into the retainer wax pattern • mesh-like surface when the retainer is cast • Eliminates the need for etching facebook.com/notesdental
- 14. Cast Mesh FPD •Advantage – Use of noble-metal alloys • Disadvantage • stiff, making it somewhat difficult to adapt to detail of the abutment tooth • Wax runs too freely into mesh – blocks undercut compromising retentivity. facebook.com/notesdental
- 15. Virginia bridge • lostsalt technique • particle-roughened retainers by incorporating salt crystals into the retainer patterns to produce roughness on the inner surfaces facebook.com/notesdental
- 16. Virginia bridge facebook.com/notesdental • Sievedcubic salt crystals (NaCl) - sprinkled over the outlined area sparing 0.5-1.0 mm wide crystal free margin • retainer patterns were fabricated from resin • removed from the cast- resin was polymerized • cleaned with a solvent, • placed in water in an ultrasonic cleaner to dissolve the salt crystals • left cubic voids in the surface
- 17. Air abrasion facebook.com/notesdental • Airabrasion with aluminum oxide in conjunction with above technique improves retention • Co-Cr castings - with 4- methacryloxyethyl trimellitate anhydride (4-MET A) resin • Ni-Cr alloys - oxidation with a dilute solution of sulfuric acid and potassium manganate prior to air abrassion
- 18. Tin Plating • Doneon noble metal alloys • Requires particle abrasion of the alloy surface • Uses a tin amide solution facebook.com/notesdental
- 19. Resin cements facebook.com/notesdental • Unfilledresin - polymethyl methacrylate : Rochette • Unfilled/filled composite resins: perforated retainers • Modified unfilled/filled composite resin with a thin film thickness - electrolytic etching • chemically active - 4-MET A – Chemically react with surface of – not on microretention in the surface of the metal for bond strength
- 20. Advantag e facebook.com/notesdental • Reduced cost –not as significant as was first thought when little or no preparation was involved • No anesthetic needed • Supragingival margins • Rebonding Possible • Minimal tooth preparation – More conservative and less likely to create problems in unblemished abutment teeth
- 21. Disadvantages facebook.com/notesdental • Irreversible • UncertainLongevity : some concern about the longevity of this type of prosthesis • No Space Correction: edentulous space is significantly wider than the mesiodistal width of the tooth that would normally occupy the space • No Alignment Correction • Difficult Temporlzation
- 22. Indications • Replacement ofmissing anterior teeth in children and adolescents • Caries free abutment teeth or unrestored abutments • Mandibular incisor replacement facebook.com/notesdental
- 23. • Maxillary incisor replacement •Periodontal splints • Post orthodontic stabilisation • Prolonged placement of interim prosthesis facebook.com/notesdental
- 24. • Prolonged placementof interim prosthesis • Single posterior tooth replacement • Significant clinical crown length • Excellent moisture control facebook.com/notesdental
- 25. Contraindications facebook.com/notesdental • Parafunctional habits •Long edentulous span • Extensive caries • Restored or damaged abutments
- 26. • Compromised enamel •Nickel sensitivity • Deep vertical overbite • Incisors with thin faciolingual dimensions facebook.com/notesdental
- 27. Resin retained fixedpartial denture facebook.com/notesdental Advantage Disadvantage Indication Contraindication •Minimal tooth preparation •Minimal potential for pulpal trauma •Anaesthesia not required •Supragingival margin •Easy impression •Provisional required •Reduced chair time •Reduced patient expense •Rebinding possible •Reduced longevity •Enamel modification required •Space correction is difficult •Good alignment of abutment teeth is required •Esthetic is compromised on posterior teeth •Replacement of missing anterior teeth in children and adolescents •Short span •Unrestored abutments •Single posterior teeth •Significant crown length •Excellent moisture control •Parafunctional habits •Long edentulous spans •Restored or damaged abutments •Compromis ed enamel •Significant pontic width disprepancy •Deep vertical overlap •Nickel allergy
- 28. Refrences facebook.com/notesdental • T. Shillinburg.Fundamentals of Fixed Prosthodontics, III edition • T. Shillinburg. Fundamentals of Fixed Prosthodontics, IV edition • Rosenstiel, Land, Fujimoto. Contemperory Fixed Prosthodontics, III edition