Resin bonded fixed partial denture

Resin Bonded Fixed Partial Denture

Deepak K. Gupta (Final Year)

Department of ProsthodonticsInstitute of Dental Education and Advance Studies, Gwalior

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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


Development of Acid etching of enamel

• Buonocore in 1955

• Less destructive means of attaching FPD’s

• Ibsen - attachment of an acrylic resin ponticto an unprepared tooth using a composite bonding resin


Classification of RBFPD

• Classified on the basis progression of development:

– Rochette bridge

– Maryland bridge

– Cast Mesh

– Virginia bridges


Rochette bridge

• wing-like retainers,

• with funnel-shaped perforations through them to enhance resin retention

• combined mechanical retention with a silanecoupling agent to produce adhesion to the metal


Disadvantage• Weakening of the 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


Maryland Bridge

• etched-metal prosthesis

• 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


Two-step process• Livaditis and 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


1-step

• McLaughlin

• faster technique

• combined solution of sulfuric and hydrochloric acids placed in an activated ultrasonic cleaner for 99 seconds passing electrical current.


Disadvantage

• Technique sensitive

• Lab dependent

• Varies with metal type

• Prone to contamination

• Cannot be done with noble metal alloys


Chemical Etching

• 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


Modification

• Retainers coated with 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.


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


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.


Virginia bridge

• lost salt technique

• particle-roughened retainers by incorporating salt crystals into the retainer patterns to produce roughness on the inner surfaces


Virginia bridge

• Sieved cubic 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


Air abrasion

• Air abrasion 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 manganateprior to air abrassion


Tin Plating

• Done on noble metal alloys

• Requires particle abrasion of the alloy surface

• Uses a tin amide solution


Resin cements

• Unfilled resin - 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


Advantage

• 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


Disadvantages

• Irreversible

• Uncertain Longevity : 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


Indications• Replacement of missing

anterior teeth in children and adolescents

• Caries free abutment teeth or unrestoredabutments

• Mandibular incisor replacement


• Maxillary incisor replacement

• Periodontal splints

• Post orthodontic stabilisation

• Prolonged placement of interim prosthesis


• Prolonged placement of interim prosthesis

• Single posterior tooth replacement

• Significant clinical crown length

• Excellent moisture control


Contraindications

• Parafunctional habits

• Long edentulous span

• Extensive caries

• Restored or damaged abutments


• Compromised enamel

• Nickel sensitivity

• Deep vertical overbite

• Incisors with thin faciolingual dimensions


Resin retained fixed partial dentureAdvantage Disadvantage Indication Contraindication

•Minimal tooth preparation•Minimal potential for pulpal trauma•Anaesthesia not required•Supragingivalmargin•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•Unrestoredabutments•Single posterior teeth•Significant crown length•Excellent moisture control

•Parafunctionalhabits•Long edentulousspans•Restored or damaged abutments•Compromised enamel•Significant ponticwidth disprepancy•Deep vertical overlap•Nickel allergy


Refrences

• T. Shillinburg. Fundamentals of Fixed Prosthodontics, III edition

• T. Shillinburg. Fundamentals of Fixed Prosthodontics, IV edition

• Rosenstiel, Land, Fujimoto. ContemperoryFixed Prosthodontics, III edition


Health & Medicine

Resin bonded fixed partial denture