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RETAINERS IN FPDPrepared by dr.AmitPg final year prosthodonticsComponents of fpdClassification of retainersExtracoronal retainersFull veneer crownsIndicationContraindicationAdvantageDisadvantagePreparationPartial veneer crownsIndicationContraindicationAdvantageDisadvantagePreparation

CONTENTS

COMPONENTS OF FDP

The part of a fixed partial denture which unites the abutment to the remainder of the restoration. Gpt-8Retainers-

Retainers with pontics Abutment

Bridge Should cause least amount of destruction to the abutmentleast destroys the outline form of the toothMarginal line should be Finished with great accuracyIDEAL RETAINER8Rigidity withstand the requisite loadFunctional adaptation and protect the tooth against its fractureLeast destroys the cervical marginal ridgePositioned margins at less susceptible to caries or recurrence of caries Preparation should be made without trauma to the pulp or surrounding tissueAccurate complement to the lost tooth structureCleansableesthetic AgeD.M.F. RateEdentulous spacePeriodontal supportArch position of toothSkeletal relationshipInterocclusal conditions such as crown lengthOral hygiene statusVitality of abutments

Selection of retainer1. based on the tooth coverage- full veneer crown partial veneer crown conservative retainers telescopic retainers

2. Based on material being used- all metal retainers metal ceramic retainers all ceramic retainers all acrylic retainers Type of retainers-Criteria of selecting type of retainer-Abutment teeth are aligned parallel to one another full veneer crown can be givenPartial veneer crown are preferred for non carious abutments or abutments with large restorations but intact facial or buccal surfaces.Endodontically treated tooth may have to be restored with core post before designing the retainer

Appearance-Full veneer crown show superior esthetics to partial veneer crownAnterior restoration all ceramicsBest to retain facial or buccal surfaces of natural teeth as they provide best estheticsIn case with inadequate pontic space full coverage restoration can be designed for better appearance EXTRACORONAL RETAINERS

Complete PARTIAL Coverage crownsCOMPLETE VENEER CROWN restore all surfaces of the clinical crown.The restorative material may be:1: All Metal.2: All Ceramic.3: Metal-Ceramic. 4: Metal with processed resin.COMPLETE VENEER CROWNThe Metal-Ceramic Crown Preparation

18Fixed/fixed bridgeA prosthesis where the artificial tooth or teeth (pontic) is supported rigidly on either side by one or more abutment teeth.It is a strong and retentive restoration for replacing missing teeth. It can be used for single or multiple missing units with the abutment teeth splinted together in the latter case.Fixed/fixed bridge

Fixed/fixed bridge

Fixed/fixed bridge

Fixed/movable bridgeA prosthesis where the artificial tooth or teeth is rigidly supported on one side, by one or more abutment teeth.On the other side, the abutment contain an intracoronal attachment which allows a small degree of movement between the rigid component and the other abutment tooth or teeth.Fixed/movable bridge

COMPLETE VENEER CROWNCOMPLETE VENEER CROWN restore all surfaces of the clinical crown.The restorative material may be:1: All Metal.2: All Ceramic.3: Metal-Ceramic. 4: Metal with processed resin.Metalceramic crown Used when limited occlusal space and high functional loads. Relies on ability of porcelain to bond to metal oxide. Modern metalceramic crowns have excellent aesthetics. TYPES OF ANTERIOR CROWNSIndications Teeth that require complete coverage where esthetic demands are high.Where all ceramic crown is contraindicatedExtensive tooth destruction due to caries, trauma. 27IndicationsWithin certain limits this restoration can also be used to correct the occlusion plane.As a bridge retainer28 Contraindications Patient with active caries or untreated periodontal disease.In young patients with large pulp chamber.When more conservative retainer is technically feasible. 29 Advantages It is more durable than all ceramic crown and has superior marginal fit.It can also serve as retainer for fixed partial denture.Natural appearance can be closely matched by good technique.30AdvantagesThe required preparation often is much less demanding than for partial coverage retainers.31 Disadvantages The preparation require significant reduction of tooth to provide sufficient space for the restorative materials.For better esthetic facial margin is often placed sub-gingivally ,which increases the risk of periodontal diseases. 32Can have metal (when very limited occlusal space) or porcelain palatal surface. Often have butt joint labially (1.5 mm shoulder to allow adequate metal and porcelain for aesthetics) and chamfer margin palatally.A porcelain jacket crown (PJC) consists of a layer of porcelain which covers the entire crown of the tooth.A porcelain bonded crown (PBC) is one which is constructed in metal alloy with porcelain fused to either all or most of its surfaces.Porcelain jacket and porcelain bonded crownPJC: When the anterior teeth are heavily restored with composite restorations or where tooth material has been lost as a result of trauma.PBC: In situations where a stronger restoration is required, such as the presence of minimal interocclusal clearance.INDICATIONSImproved appearance. The shade and translucency of adjacent teeth can be recreated in porcelain work.The strength of this type of restoration is its major advantage.ADVANTAGESUsed when aesthetics of prime concern. Problem in high-load situation as porcelain in thin section and liable to fracture. Not usually suitable for posterior teeth. Usually butt joint around whole preparation (minimum 1 mm shoulder to allow adequate porcelain for aesthetics).Need 1.5 mm thickness of porcelain incisally.Porcelain jacket crownPorcelain crowns with superior aesthetics and with higher tensile strength than conventional porcelain jacket crowns are finding increasing use employ sintered alumina cores or injection moulding of ceramic. Require even reduction; preparation similar to a conventional aluminous porcelain jacket crown. Use of dentine-bonded crowns and reverse three-quarter crowns involve significantly less tooth preparation.Other anterior crowns

Maxillary central incisor prepared for all-ceramic crown

Metalceramic crown preparation of upper anterior tooth.

Porcelain jacket crown preparation of upper anterior tooth.METAL-CERAMIC RESTORATIONALSO CALLED PORCELAIN FUSED TO METAL RESTORATION (PFM).

CONSIST OF A CERAMIC LAYER BONDED TO A THIN CAST METAL COPING THAT FITS OVER THE TOOTH PREPARATION.

METAL CERAMIC RESTORATIONCombines the strength and accurate fit of a cast restoration with the cosmetic effect of a ceramic crown.

METAL-CERMIC RESTORATIONWITH THE METAL UNDERSTRUCTURE,METAL-CERAMIC RESTORATIONS HAVE GREATER STRENGTH THAN RESTORATIONS MADE OF CERAMIC ALONE.

METAL-CERMIC RESTORATIONCan be used in a wide variety of situations including the replacement of missing teeth with fpds.

METAL-CERMIC RESTORATIONIs a combination of metal and Ceramic.The tooth preparation is also combination of deep reduction facially and shallower reduction lingually.There may be a wing on each proximal surface where the deep reduction ends and the shallower proximal reduction begins.

METAL-CERMIC RESTORATIONADEQUATE REDUCTION IS ESSENTIAL FOR ACHIEVING A GOOD ESTHETIC RESULT.

METAL-CERMIC RESTORATIONInadequate space for a sufficient thickness of ceramic material-1. Poorly contoured restoration affecting both esthetic and health of the surrounding gingiva.

METAL-CERMIC RESTORATION2.The shade and translucency of the restoration will not match the adjacent natural teeth.

ANTERIOR METAL-CERAMIC CROWNSA UNIFORM REDUCTION OF APPROXIMATELY 1.2MM IS NEEDED OVER THE ENTIRE FACIAL SURFACE.

ANTERIOR METAL-CERAMIC CROWNSTO ACHIEVE ADEQUATE REDUCTION WITHOUT ENCROACHING UPON THE PULP FACIAL SURFACE PREPARED IN TWO PLANES THAT CORRESPOND ROUGHLY TO THE TWO GEOMETRIC PLANES PRESENT ON THE FACIALSURFACE OF AN UNCUT TOOTH

ANTERIOR METAL-CERAMIC CROWNSFACIAL SURFACE IS PREPARED IN A SINGLE PLANE THAT IS AN EXTENSION OF THE GINGIVAL PLANE INCISAL EDGE WILL PROTRUDE RESULTING IN BAD SHADE MATCH OR OVERCONTOURED BLOCK.

ANTERIOR METAL-CERAMIC CROWNSFACIAL SURFACE PREPARED IN ONE PLANE THAT HAS ADEQUATE FACIAL REDUCTION IN THE INCISAL ASPECT- FACIAL SURFACE OVERTAPERED AND TOO CLOSE TO THE PULP.

ARMAMENTARIUMLAB KNIFE WITH NO:25 BLADESILICONE PUTTYROUND END TAPERED DIAMONDSMALL WHEEL DAIMONDLONG NEEDLE DAIMONDRADIAL FISSURE BUR (ROUNDED SHOULDER)MODIFIED BINANGLE CHISEL

Preparation Armamentarium :- 1.Round-tipped rotary diamond or carbides. 2.football or wheel shape diamond 3.flat end, taper diamond 4.finishing stones 5.explore and periodontal probe 6.hatchet and chiesel 55ANTERIOR METAL-CERAMIC CROWNSSILICONE INDEX MADE BEFORE TOOTH PREPARATION

TOOTH BADLY BROKEN DOWN, INDEX MADE ON WAXED UP DIAGNOSTIC CAST.

ANTERIOR METAL-CERAMIC CROWN PREPARATIONSTEP NO : 1PLACEMENT OF DEPTH ORIENTATION GROOVES - ( 1.2MM )THE LABIAL GROOVES CUT IN TWO SETSONE SET PARALLEL WITH THE GINGIVAL HALF OF LABIAL SURFACEONE SET PARALLEL WITH THE INCISAL HALF OF LABIAL SURFACE

ANTERIOR METAL-CERAMIC CROWN PREPARATION

ANTERIOR METAL-CERAMIC CROWN PREPARATIONANTERIOR METAL-CERAMIC CROWN PREPARATIONSTEP NO : 2INCISAL REDUCTION- (2MM)ROUND END TAPERED DAIMOND.

ANTERIOR METAL-CERAMIC CROWN PREPARATIONInadequate incisal reduction results in poor incisal translucencyANTERIOR METAL-CERAMIC CROWN PREPARATIONSTEP NO : 3LABIAL REDUCTION(INCISAL HALF)ROUND- END TAPERED DAIMOND.

ANTERIOR METAL-CERAMIC CROWN PREPARATIONSTEP NO :4LABIAL REDUCTION(GINGIVAL HALF)ROUND-END TAPERED DAIMOND

ANTERIOR METAL-CERAMIC CROWN PREPARATIONSTEP NO : 5LINGUAL REDUCTION(0.7 -1MM )SMALL WHEEL DAIMOND.

ANTERIOR METAL-CERAMIC CROWN PREPARATIONSTEP NO :6INITIAL PROXIMAL REDUCTIONLONG NEEDLE DIAMOND

ANTERIOR METAL-CERAMIC CROWN PREPARATIONSTEP NO : 7LINGUAL AXIAL REDUCTIONROUND - END TAPERED DAIMOND.

ANTERIOR METAL-CERAMIC CROWN PREPARATIONSTEP NO : 8SMOOTHENING THE SHARP ANGLES

ANTERIOR METAL-CERAMIC CROWN PREPARATION

ANTERIOR METAL-CERAMIC CROWN PREPARATIONIMPROVED ESTHETICS

ALL CERAMIC LABIAL MARGIN

THIS ELIMINATES THE METAL COLLAR AT THE FACIOGINGIVAL MARGIN OF THE FINISHED METAL-CERAMIC RESTORATION

ANTERIOR METAL-CERAMIC CROWN PREPARATION

POSTERIOR METAL-CERAMIC CROWNSPOSTERIOR METAL-CERAMIC CROWNSSTEP NO : 1OCCLUSAL REDUCTION FOLLOWED BY FUNCTIONAL CUSP BEVEL

POSTERIOR METAL-CERAMIC CROWNSSTEP NO : 2DEPTH ORIENTATIONGROOVES

POSTERIOR METAL-CERAMIC CROWNSSTEP NO :3FACIAL REDUCTION-OCCLUSAL HALF

POSTERIOR METAL-CERAMIC CROWNSTEP NO :4

FACIAL REDUCTIONGINGIVAL HALF

POSTERIOR METAL-CERAMIC CROWNSTEP NO: 5

PROXIMAL AXIAL REDUCTION

POSTERIOR METAL-CERAMIC CROWNSTEP NO :6

LINGUAL AXIAL REDUCTION

POSTERIOR METAL-CERAMIC CROWNSTEP NO : 7

AXIAL FINISHING

POSTERIOR METAL-CERAMIC CROWNSTEP NO :8

GINGIVAL BEVEL

POSTERIOR METAL-CERAMIC CROWN

POSTERIOR METAL-CERAMIC CROWN

POSTERIOR METAL-CERAMIC CROWNAll ceramic crownsIndications:High esthetic requirementConsiderable proximal cariesIncisal edge reasonably intactEndodontically treated teeth with post and coresFavourable distribution of occlusal load

Contraindications:When superior strength is warranted because of absence of reinforcing metal substructure.Significant caries with insufficient coronal tooth structure for support.Thin teeth faciolingually.Unfavourable distribution of occlusal load.

Advantages:Superior esthetics.Good tissue response even for subgingival margins.Slightly more conservative of facial wall.

Disadvantages:Reduced strength compared to metal ceramic crown.Proper preparation extremely critical to ensure mechanical success.Least conservative.Brittle nature of material.Causes wear on the functional surfaces of natural teeth that oppose porcelain restorations.

PARTIALVENEERCROWNAn extracoronal metal restoration that covers only part of the clinical crown is considered to be a partial veneer crown.Definition of Partial Veneer CrownTYPES OF PARTIAL VENEER CROWNTYPES OF PARTIAL VENEER RETAINERS 1.Proximal boxes2.Seven eight crowns3.Reverse three quarter crown 4.Proximal half crown1 Posterior three quarter crowns2 anterior three quarter crown3 pin modified three quarter crownRestores the occlusal surface & three of the four axial surfaces (not including the facial surface).It covers three-fourth of the gingival circumference of the tooth. The facial surface commonly remains untouched.1: THREE QUARTER CROWN:

THREE QUARTER CROWN

THREE QUARTER CROWNRestores all surfaces except the lingual surface. It is indicated on mandibular molars with severe lingual inclination used as FPD abutments.

2: REVERSE THREE QUARTER CROWN:

REVERSE THREE QUARTER CROWNThey are the extensions of the crowns to include a major portion of the facial surface. It covers seven eights of the gingival circumference of the tooth.

3: SEVEN-EIGHTS CROWN:It is generally indicated for maxillary molars & premolars that are sound mesially but have extensive carious involvement or a previous restoration on the distal surface. The seven eights crown preparation extends the distal finish line to the midfacial surface.3: SEVEN-EIGHTS CROWN:

SEVEN-EIGHTS CROWNIt is actually a three-quarter crown rotated 90 degrees, preserving the distal surface of the tooth while veneering the remaining surfaces.Primarily indicated for the distal retainer of a mandibular FPD with mesially tilted molar abutment.It is contraindicated if the distal surface is carious.Also c/as one-half crown. 4: MESIAL HALF CROWN:

MESIAL HALF CROWN:

MESIAL HALF CROWN:

Partial Veneer Crown

Partial veneer crowns generally include all tooth surfaces except the buccal or labial wall in the preparation.Whenever feasible, a partial-coverage restoration should be selected rather than a complete veneer crown.However, the preparation is more demanding and is not routinely provided by practitioners.Partial Veneer CrownIntact or minimally restored teeth.Teeth with crown length that is average or that exceeds the average.Teeth with normal anatomic crown for, i.e. without excessive cervical constriction.Anterior teeth with adequate labiolingual thickness.Teeth with sufficient bulk because they can accommodate the necessary retentive features.

INDICATIONS6: To restore posterior teeth that have lost moderate amounts of tooth structure, provided the buccal wall is intact and well supported by sound tooth structure. 7: Used as retainers for a FPD or where restoration or alteration of the occlusal surface is needed. 8: Used as retainers, to reestablish anterior guidance.9: To splint teeth. INDICATIONSTeeth that have a short clinical crown because retention may not be adequate. Retainers for long-span FPDs.Endodontically treated teeth, especially anteriors, because insufficient supporting tooth structure remains for the retentive features.Endodontically treated posterior teeth if the buccal cusps are weakened by the access cavity.

CONTRAINDICATIONS5: Teeth with an extensively damaged crown. 6: Dentitions with active caries or periodontal disease. 7: Teeth that are proximally bulbous. Making the necessary proximal grooves on these teeth is likely to leave unsupported enamel. 8: Thin teeth of restricted faciolingual dimension.9: Poorly aligned abutment teeth.

CONTRAINDICATIONSConservation of tooth structure. Reduced pulpal and periodontal insult during tooth preparation. Access to supragingival margins is rather easy and allows the operator to perform selected finishing procedures that are more difficult or impossible with complete coverage restorations.Access is also better for oral hygiene. Because less of the margin approximates the soft tissues subgingivally, there is less gingival involvement than with complete coverage.ADVANTAGESDuring cementation of a partial veneer, the luting agent can escape more easily, which produces relatively good seating of the restoration. Because of direct visibility, verification of seating and cement removal are simple.After cementation, the remaining intact facial or buccal tooth structure permits electric vitality testingADVANTAGESPartial veneer restorations have less retention and resistance than complete cast crowns. Preparing the tooth for this type of coverage is difficult, primarily because only limited adjustments can be made in the path of withdrawal.The placement of grooves, boxes, and pinholes requires dexterity from the operator.Some metal is displayed in the completed restoration, which may be unacceptable to patients with high cosmetic expectations.DISADVANTAGESTOOTH PREPARATION FOR THREE-QUARTER CROWN1. Handpiece2. Small round diamond3. Small wheel diamond4. Long needle diamond5. Torpedo diamond6. Torpedo bur

Armamentarium7. No. 169L bur8. No. 170L bur9. Flame diamond10. Flame bur11. Enamel hatchet

ArmamentariumAs stated, with the advent of metal-ceramic restorations, the use of partial veneers on anterior teeth has become rare. Nevertheless, two anterior partial veneer crown preparations are worthy of consideration.ANTERIOR PARTIAL VENEER CROWN PREPARATIONS

The three-quarter crown on a maxillary canine is probably one of the most demanding of all tooth preparations.It involves the proximal and lingual surfaces and leaves the facial surface intact.The greater degree of difficulty stems from the different shape of the canine tooth. Unless the placement of grooves is determined very precisely in advance, there will be an undesirable display of metal in the interproximal embrasures. The relatively short proximal walls do not allow much correction after initial groove placement. Similarly, the greater degree of curvature in each proximal wall immediately adjacent to the contact area significantly influences the location of the preparation's facial margin.Maxillary Canine Three-quarter Crown1191. Remove enough enamel to allow 1 mm of metal thickness. The design of the incisal bevel should prevent contact between opposing teeth and the incisal margin. However, the original configuration of the facial surface should be preserved without significant Incisal and Lingual Reduction

The maxillary canine three-quarter crown preparation. A, A guiding groove is placed on the lingual surface. B, Half the lingual surface is reduced. Clearance is verified before reduction of the other half. C, Lingual reduction is completed, with an incisal bevel placed. No significant change has occurred in the incisocervical height. D, After an alignment groove is placed in the center of the cingulum wall, half the axial reduction is complete. Note that the path of withdrawal parallels the incisal or middle third of the labial surface. As a result, the lingual chamfer is quite wide, perhaps even resembling a shoulder. This permits paralleling of the cingulum wall, with the proximal grooves and pinhole providing additional retention.

Lingual Reduction with small Wheel diamond

Preparation on Maxillary Canine Preparation on Maxillary Canine

Incisal ReductionWith small wheel diamondLingual Axial Reduction

Preparation on Maxillary Canine

Proximal Axial reduction with needle and diamond torpedo

Preparation on Maxillary Canine

Axial finishing with torpedo

Preparation on Maxillary Canine

Proximal grooves

Proximal flares

Preparation on Maxillary Canine

Incisal offset

Preparation on Maxillary Canine

Incisal bevel with flame shaped Diamond bur

Preparation on Maxillary Canine

Preparation on Maxillary CanineE, Axial reduction is completed. Any final modification of the path of withdrawalis done at this time before groove placement. F, Proximal grooves. The visible mesial groove hasbeen flared, but unsupported enamel remains on both grooves where they meet the incisal bevel.G, Completed preparation. The lingual pinhole is surrounded by adequate dentin. Note the horizontalledge prepared before pinhole placement.

Completed three-quarter crown preparation.Note the location of the facial margin relative to the adjacent teeth. Sufficient interproximal clearance has been established, but unnecessary display of metal is avoided.

Conservative retainers-Require minimal tooth reductionAcid etchingThese dentures do not accept heavy loadsIndicated for anterior teethHave a small metallic extension which are designed to be luted directly onto the lingual surface of the abutment tooth using resin cement resin bonded fpd-

Missing anterior teethRetainer with wingsWings bonded to the lingual surface of the abutment teeth Advantages- - non invasive to dentine - conservative preparation - reduced cost and chair side time - decreased tissue irritation supragingival marginsDisadvantages- - plaque accumulation - bulky contours may be intolerable to some patients - not ideal for replacing more than one tooth Types-Rochette bridgeMaryland bridgeCastmesh fixed partial dentureVirginia bridge.

ROCHETTE BRIDGE - Wing like retainer - Funnel shaped perforationsMARYLAND BRIDGES - Mechanical retention - microporosities present on the tissue surface of the retainer created by etchingCASTMESH FPD - nylon mesh is placed on the tissue surface of the retainer wax pattern to create the microporosities - doesnt require acid etchingVIRGINIA BRIDGE - utilizes lost salt technique to create voids in the cast metal retainer - this provides mechanical retention

Indications:Retainer of fixed partial denture for abutments with sufficient enamel to etch for retention.Splinting of periodontally compromised teeh.Stabilizing dentitions after orthodontic treatment.In young patients for replacement of anterior teeth.In medically compromised, indigent and adolescent patients.

Contraindications:Patients with parafunctional habbits e.g. Bruxisum.Long endentulous spans, replacing multiple missing teeth.When the facial esthetics of abutment require improvement.Insufficient occlusal clearance to provide 2 to 3mm vertical retention e.g. abraded teeth.Inadequate enamel surfaces to bond e.g. caries, existing restorations.Incisors with extremely thin Faciolingual dimensions.

Advantages:More conservation over conventional fixed prosthodontics.Preparation confined to tooth enamel only the potential for trauma to pulp is minimized.Tissue tolarance because of supragingival margins.

Disadvantages:Longevity of prosthesis is questionable Debonding rate increases with time.Higher dislodgement rate with posterior resin retained fixed partial dentures.

Indications for multiple retainersAbutment teeth with short roots.Lack of sufficient bone support.Density of alveolar bone.Excessive length span.Excessive lever arm action because of shape of anterior arch.Distal extension of pontic for increased function.Replacement of a missing cuspid.

The objective in selection of retainer whether it involves a single tooth, several teeth or complete restoration of masticatory mechanism, it should restore and maintain function of dental arch. It should be therefore both restorative and preventive.conclusionTo accomplish this objective preventive as well as theraputic measures should be utilized. The efficiency in selecting the retainer depends on the intelligent application of mechanical, physiological, hygienic and esthetic principles within the limits of the supporting tissues.As it is the critical component of fixed partial denture we have to give atmost care in selection of retainer to achieve the goal in the success of fixed partial denture.

A.E. Kahn : Partial versus full coverage. J. Prosthet. Dent. 10:167-178, 1960.Edger Kopp: Partial veneer retainers. J. Prosthet. Dent. 23(4): 412-419, 1970.Johnstons Modern Practice in fixed Prosthodontics 4th edition 1986.Joseph E. Ewings Fixed Partial Prosthesis 2nd edition 1959.

References:Lowerence Weinberg: Vertical non parallel pininlay fixed partial prosthesis. J. Prosthet. Dent. 23: 420-433, 1970.Stephen F. Rosenstial, Martin F. Land. Junhei Fujimoto: Contemporary fixed prosthodontics 2nd edition 1995 Indian edition 1959.Schelling burg: Fundamentals of Fixed Prosthodontics. Second edition.Sturdevent: The Art and Science of Operative Dentistry. Second edition.

Someul E. Guyer: Multiple preparation for fixed prosthodontics. J. Prosthet. Dent. 23: 529-553, 1970.W.F. Malone, D.L. Koth, E. Carazos: Tylmans theory and practice of fixed prosthodontics. 8th edition, Indian edition 1997.Weinberg: A new design for posterior porcelain fused to metal prosthesis. J. Prosthet. Dent. 17: 178-194, 1967.W.H. Wilson and R.L. Lang: Practical crown and Bridge prosthodontics.