Introduction of Removable Partial
Denture
Introduction of Introduction of Removable Partial Removable Partial
Denture Denture
By : Dr By : Dr ZaihanZaihan AriffinAriffinBDS(MalayaBDS(Malaya), Grad. Dip In Clinical Dentistry (Adelaide),), Grad. Dip In Clinical Dentistry (Adelaide),Doctor of Clinical Dentistry (Adelaide),Doctor of Clinical Dentistry (Adelaide),FRACDS (Australia)FRACDS (Australia)
Aims & ObjectivesAims & ObjectivesWhat are the aims of providing a RPD?What are the aims of providing a RPD?Discuss the Advantages and Discuss the Advantages and Disadvantages of providing RPDDisadvantages of providing RPD
Clinical and lab stages involvedClinical and lab stages involvedDescribe the Components and their Describe the Components and their Function of RPDFunction of RPDDefine Support, Retention and StabilityDefine Support, Retention and StabilityDefine the Kennedy Classification of Define the Kennedy Classification of edentulous spacesedentulous spaces
Removal partial Denture :Removal partial Denture :An appliance worn in the mouth, An appliance worn in the mouth, which replaces missing teeth and which replaces missing teeth and gums.gums.
Functions : Functions : to improve oral functions, aesthetic to improve oral functions, aesthetic and preservation of remaining tissue.and preservation of remaining tissue.
Replace missing teeth. Why?Replace missing teeth. Why?Aesthetics /Aesthetics /AppearanceAppearanceFunctionFunctionMastication Mastication SpeechSpeech
-- Maintaining the health of the Maintaining the health of the masticatorymasticatory systemsystem-- Preventing undesirable tooth movementPreventing undesirable tooth movement-- Improving distribution of Improving distribution of occlusalocclusal loadload-- Preparation for complete denturesPreparation for complete dentures
Preservation of what remains (soft tissue and hard Preservation of what remains (soft tissue and hard tissue).tissue).Prevent movement of remaining teeth opposing teethPrevent movement of remaining teeth opposing teethOver eruptionOver eruptionTiltingTiltingMesialMesial/distal drift/distal driftPrevent excessive wear on remaining teethPrevent excessive wear on remaining teeth
Consequences of tooth lossConsequences of tooth loss
OvereruptionOvereruption..DriftingDriftingAltered occlusionAltered occlusionUnaestheticUnaestheticReduces in function Reduces in function and speechand speech
AdvantagesAdvantagesRemovableRemovableCan replace many teethCan replace many teethCan be used in free end saddles casesCan be used in free end saddles casesCan replace hard and soft tissues defectsCan replace hard and soft tissues defectsCost Cost –– cheap when compared to bridges cheap when compared to bridges or implant.or implant.Quick & simply can madeQuick & simply can madeEasy for modification and addition or Easy for modification and addition or repairedrepaired
DisadvantagesDisadvantagesRemovableRemovableLimited loading potentialLimited loading potentialIncreased bone Increased bone resorptionresorptionIncreased plaque accumulationIncreased plaque accumulationPoor clasping & support Poor clasping & support --tooth tooth overloadoverloadWear of denture teeth/teethWear of denture teeth/teethLimited lifetimeLimited lifetime
Type of dentureType of dentureFull dentureFull denturePartial denture Partial denture ––acrylic or Coacrylic or Co--crcrImmediate denture Immediate denture ––acrylic (commonly)acrylic (commonly)OverdentureOverdenture –– acrylic acrylic or Coor Co--crcrImplant supported Implant supported denturedentureSectional dentureSectional denture
Stages of RPD Stages of RPD arcylicarcylic
Examination and diagnosisExamination and diagnosisImpression 1Impression 1oo
Tooth preparationTooth preparationImpression 2Impression 2oo
Jaw recordJaw recordTry InTry InIssued dentureIssued dentureReview and Review and MaintenanceMaintenance
Stages of RPD CoStages of RPD Co--CrCrExamination and diagnosisExamination and diagnosisImpression 1Impression 1o o
Tooth preparationTooth preparationImpression 2Impression 2oo
Try in CoTry in Co--Cr Cr Jaw recordJaw recordTry In Try In Issued dentureIssued dentureReview and Review and MaintenanceMaintenance
Clinical Phases in TreatmentClinical Phases in Treatment
Examination, Diagnosis Examination, Diagnosis and Treatment Planningand Treatment PlanningMouth PreparationMouth PreparationMaster ImpressionsMaster ImpressionsOcclusal RecordsOcclusal RecordsInsertionInsertionMaintenanceMaintenance
Phase 1 Phase 1 E&D,TreatmentE&D,Treatment PlanningPlanning
Gathering Gathering informationsinformationsAnalyseAnalyseDerive diagnosisDerive diagnosisConsider prognosisConsider prognosisConstruct treatment Construct treatment planplan–– Discuss with patientDiscuss with patient–– Obtain consent (if Obtain consent (if
necessary)necessary)
Gathering informationGathering informationPatientPatient’’s informations informationChief complaintChief complaintHistoryHistoryAttitudes Attitudes -- Assess attitudes, Assess attitudes, expectations and motivationexpectations and motivationExaminationExaminationRadiographsRadiographs-- OPG, PA,BWOPG, PA,BWStudy modelsStudy modelsSpecial tests Special tests –– saliva test, biopsy etc.saliva test, biopsy etc.ConsultationsConsultations
ExaminationExaminationExtra oral and Intra oralExtra oral and Intra oralGeneralGeneralSoft tissues Soft tissues –– intra and extraintra and extra--oraloral
Alveolar ridges, vestibulesAlveolar ridges, vestibulesOcclusionOcclusionProsthesesProsthesesDentitionDentitionPeriodontiumPeriodontium
Risk/Benefit AnalysisRisk/Benefit AnalysisConsider patient’s:• experience, attitudes• motivation, abilities• plaque and caries levels• bone and mucosa• periodontal apparatus • type of RPD• design considerations• appearance• occlusion• masticatory efficiency• Saliva
Risk/Benefit AnalysisRisk/Benefit AnalysisIf the risks are greater than the benefits you
will probably need to consider not to construct a RPD to the patient.
Risks > Benefits Risks < Benefits
Finalise Treatment PlanFinalise Treatment Plan
• Discuss treatment options with patient
• Discuss costs involved
• Outline your responsibilities and those of the patient
• Set appointment times
• Obtain consent
11oo ImpressionImpression
Study models for:
•Diagnosis purposes•Treatment plan•Dental record•Surveying
Custom (special) trayCustom (special) trayFabricate custom (special) – for 2o
impression
Phase 2 Phase 2 -- Mouth PreparationMouth Preparationyou should prepare you should prepare the mouth by:the mouth by:
• eliminating disease (perioand caries)• completing restorations• re-evaluating the treatment plan• modifying teeth to receive the RPD
Phase 3 Phase 3 -- Master ImpressionsMaster Impressions
Objective Objective --to record accurate to record accurate impressions of the impressions of the teeth and soft tissues teeth and soft tissues so that quality so that quality dentures can be dentures can be achievedachieved
Articulated and surveyed study Articulated and surveyed study modelsmodels
Phase 4 Phase 4 -- Occlusal RecordsOcclusal RecordsObjective –
• to establish the correct relations record between the maxilla and the mandibel.
• When placement of artificial teeth, so that the final denture will be aesthetically pleasing, comfortable and compatible with the masticatory system.
• The clinical steps involved can be simple to complex.
Occlusal recordsOcclusal recordsClinical steps include:Clinical steps include:
-- review laboratory workreview laboratory work-- verify quality of impression by checking verify quality of impression by checking extensions, retention and stability of baseextensions, retention and stability of base-- fit the RPD frame fit the RPD frame -- record centric occlusion/relationrecord centric occlusion/relation-- select tooth colour and formselect tooth colour and form-- determine tooth positiondetermine tooth position
Try InTry InClinical steps include:Clinical steps include:
review laboratory workreview laboratory workverify quality of impression and check the denture verify quality of impression and check the denture by checking extensions, retention and stability of by checking extensions, retention and stability of basebaserecord centric occlusion/relation. Sometime you record centric occlusion/relation. Sometime you need to check to freeway space for complex cases.need to check to freeway space for complex cases.fit the RPD framefit the RPD framephonetic, patient comfortphonetic, patient comfortdetermine tooth position (aesthetic, midline, tooth determine tooth position (aesthetic, midline, tooth position and tooth colour and lip support)position and tooth colour and lip support)discussion of trial denture with patientdiscussion of trial denture with patient
Prepare metal framePrepare metal frame
Study models with denture Study models with denture designs, master cast.designs, master cast.
Phase 5 Phase 5 -- InsertionInsertionThe objective-
to insert the prosthesis and provide sufficient information so that the patient is able to insert and remove the RPD.
Patient must understands
• when it is to be worn and not to wear the denture
• how the denture and the oral tissues should be cleaned
•Limitation of the denture and how the denture perform
• and possible complications associated with a new denture and how to deal with them.
InsertionInsertionReviewReview::
quality of finished RPD and correctquality of finished RPD and correctextensions, retention and stabilityextensions, retention and stabilityocclusion occlusion -- including neutral zone, including neutral zone, IOD, occlusal contacts and IOD, occlusal contacts and articulationarticulation
Adjust as requiredAdjust as requiredDiscussDiscuss
appearance with patientappearance with patientuse and care of RPD and oral use and care of RPD and oral tissues limitations and possible tissues limitations and possible difficultiesdifficulties
Phase 6 Phase 6 ––PostPost--insertion and Maintenanceinsertion and Maintenance
Objective:
• to review the outcome of treatment
• to assist the patient through the learning period and when the patient is wearing the denture comfortably to provide a regular recall service
• problem arise and eventually to adjust, repair, reline/rebase or remake the RPD
Things to remember!Things to remember!
1. Saddles1. Saddles (yellow)(yellow)2. Support 2. Support (red)(red)3. Retention 3. Retention (green)(green)4. Bracing and reciprocation 4. Bracing and reciprocation (blue)(blue)5. Connector 5. Connector (black) (black) 6. Indirect retention.6. Indirect retention.
Definitions:Definitions:
Saddles:Saddles:TheThe part of a partial denture which part of a partial denture which replaces the edentulous space (missing teeth). replaces the edentulous space (missing teeth). Bounded saddles have teeth either end; Free end Bounded saddles have teeth either end; Free end saddles do not distal abutment tooth. (can be saddles do not distal abutment tooth. (can be acrylic or acrylic or subframesubframe of metal overlaid by acrylic).of metal overlaid by acrylic).
Support: Support: The ability of a denture to resist to The ability of a denture to resist to vertical forces directed towards mucosa.vertical forces directed towards mucosa.
StabilityStability : The ability of the denture to resist : The ability of the denture to resist displacing forces during functiondisplacing forces during function
Indirect retainer: Indirect retainer: a component of the a component of the denture that resists rotational or tilting denture that resists rotational or tilting movements of the denture.movements of the denture.
Major Connector: Major Connector: these join the these join the edentulous saddles of the denture edentulous saddles of the denture together and provide cross arch bracing.together and provide cross arch bracing.
Minor connector: Minor connector: these components join these components join the rests, clasps, reciprocals etc to the the rests, clasps, reciprocals etc to the major connector.major connector.
Retention ( Direct Retention): Retention ( Direct Retention): The ability of a denture to resist The ability of a denture to resist movement away from the supporting movement away from the supporting tissues, i.e. away from the teeth or tissues, i.e. away from the teeth or mucosa. Direct retention can mucosa. Direct retention can provided by engaging the undercut provided by engaging the undercut on the tooth.on the tooth.
Components of a dentureComponents of a dentureClasps: Clasps: these shaped pieces of metal these shaped pieces of metal (cast Cr/Co, gold or stainless steel) are (cast Cr/Co, gold or stainless steel) are used to keep the partial denture in placeused to keep the partial denture in place
Rests: Rests: these are parts of the denture these are parts of the denture base that fit onto the (prepared) surfaces base that fit onto the (prepared) surfaces of the teeth close to the edentulous saddle of the teeth close to the edentulous saddle to take some of the to take some of the masticatorymasticatory load away load away from the mucosa onto these teeth.from the mucosa onto these teeth.
Reciprocals: Reciprocals: a part of the denture that a part of the denture that resists the action of a clasp on a tooth as resists the action of a clasp on a tooth as the denture is inserted or removed from the denture is inserted or removed from the mouth.the mouth.
Support (rest)
Clasp -retention
bracing
Major connector
saddle
Things to remember!Things to remember!
1. Saddles1. Saddles (yellow)(yellow)2. Support 2. Support (red)(red)3. Retention 3. Retention (green)(green)4. Bracing and reciprocation 4. Bracing and reciprocation (blue)(blue)5. Connector 5. Connector (black) (black) 6. Indirect retention.6. Indirect retention.
Kennedy Classification of Kennedy Classification of Edentulous SaddlesEdentulous SaddlesKennedy Classification I: Bilateral Free Kennedy Classification I: Bilateral Free End SaddlesEnd SaddlesKennedy Classification II: Unilateral Free Kennedy Classification II: Unilateral Free End SaddleEnd SaddleKennedy Classification III: Unilateral Kennedy Classification III: Unilateral Bounded SaddleBounded SaddleKennedy Classification IV: Bounded Kennedy Classification IV: Bounded Saddle Across the MidlineSaddle Across the MidlineModifications to this classification for extra Modifications to this classification for extra missing teeth and their edentulous saddles missing teeth and their edentulous saddles is permitted for Kennedy Classes I, II and is permitted for Kennedy Classes I, II and III But NOT Class IVIII But NOT Class IV
Things to remember!Things to remember!
1. Saddles1. Saddles (yellow)(yellow)2. Support 2. Support (red)(red)3. Retention 3. Retention (green)(green)4. Bracing and reciprocation 4. Bracing and reciprocation (blue)(blue)5. Connector 5. Connector (black) (black) 6. Indirect retention.6. Indirect retention.
SupportSupportHOW: HOW: Mucosa and underlying BoneMucosa and underlying BoneRests on Teeth: Rests on Teeth: occlusalocclusal; ; cingulumcingulum; ; incisalincisal; telescopic copings, precision ; telescopic copings, precision attachmentsattachmentsWHY: WHY: Increase Increase masticatorymasticatoryefficiencyefficiencyWHERE: WHERE: Adjacent to the saddle it Adjacent to the saddle it has to support (commonly).has to support (commonly).
Support (rest)
Clasp -retention
bracing
Major connector
saddle
Things to remember!Things to remember!
1. Saddles1. Saddles (yellow)(yellow)2. Support 2. Support (red)(red)3. Retention 3. Retention (green)(green)4. Bracing and reciprocation 4. Bracing and reciprocation (blue)(blue)5. Connector 5. Connector (black) (black) 6. Indirect retention.6. Indirect retention.
DIRECT RETENTIONDIRECT RETENTIONClasps: provide direct retention by Clasps: provide direct retention by engaging the undercut area on the engaging the undercut area on the tooth.tooth.Types: Types: GingivallyGingivally or or OcclusallyOcclusallyApproachingApproachingNames: Ring, Circumferential, INames: Ring, Circumferential, I--bar, bar, TT--bar, Lbar, L-- bar, Reverse.bar, Reverse.Should includes a rest, a clasp arm Should includes a rest, a clasp arm and a reciprocal arm.and a reciprocal arm.
Retention will depend on:Retention will depend on:
Dept of undercut : 0.25 mmDept of undercut : 0.25 mm-- cast cobalt cast cobalt chrome: 0.5 mmchrome: 0.5 mm-- ssss0.75 mm 0.75 mm –– gold.gold.
Position of undercut: ex: high survey line Position of undercut: ex: high survey line –– gingivagingiva approaching claspapproaching claspPosition of the toothPosition of the toothOcclusionOcclusionShape of the Shape of the sulcussulcusPeriodontal healthPeriodontal healthMaterial of denture baseMaterial of denture base
Figure A Figure B
Things to remember!Things to remember!
1. Saddles1. Saddles (yellow)(yellow)2. Support 2. Support (red)(red)3. Retention 3. Retention (green)(green)4. Bracing and reciprocation 4. Bracing and reciprocation (blue)(blue)5. Connector 5. Connector (black)(black)6. Indirect retention.6. Indirect retention.
ConnectorsConnectors
Major:Major: to join the Saddles Areas togetherto join the Saddles Areas togetherMandibularMandibular: Lingual bar, Lingual plate, : Lingual bar, Lingual plate, Sublingual bar.Sublingual bar.Maxilla: Full palatal coverage; Anterior Maxilla: Full palatal coverage; Anterior palatal bar, Posterior palatal bar, Anterior palatal bar, Posterior palatal bar, Anterior and horseshoe connector.and horseshoe connector.Minor:Minor: to join the rests, clasps and to join the rests, clasps and reciprocal elements to the major reciprocal elements to the major connector.connector.
Things to remember!Things to remember!
1. Saddles1. Saddles (yellow)(yellow)2. Support 2. Support (red)(red)3. Retention 3. Retention (green)(green)4. Bracing and reciprocation 4. Bracing and reciprocation (blue)(blue)5. Connector 5. Connector (black) (black) 6. Indirect retention.6. Indirect retention.
Indirect retention :Indirect retention :
Indirect retainer derived by placing components so as to Indirect retainer derived by placing components so as to resist resist ‘‘rotational or rotational or ‘‘tippingtipping’’ forces of the denture around the forces of the denture around the retainers ex: by position of clasps and rest and type of the retainers ex: by position of clasps and rest and type of the connector.connector.
F = Fulcrum F = Fulcrum —— indirect retainer, a indirect retainer, a component which obtains support.component which obtains support.R = Resistance R = Resistance —— retention generated by retention generated by the clasp.the clasp.E = Effort E = Effort —— displacing force, displacing force, egeg a bolus a bolus of sticky food.of sticky food.
Ex: If the design is modified by placing a rest on the premolar tooth, this rest (indirect retainer) becomes the fulcrum of movement of the saddle in an occlusal direction causing the clasp to move up the tooth, engage the undercut and thus resist the tendency for the denture to pivot.
It can thus be seen that to obtain indirect retention It can thus be seen that to obtain indirect retention the clasp normally be placed between the saddle and the clasp normally be placed between the saddle and the indirect retainerthe indirect retainer
Things to remember!Things to remember!
1. Saddles1. Saddles (yellow)(yellow)2. Support 2. Support (red)(red)3. Retention 3. Retention (green)(green)4. Bracing and reciprocation 4. Bracing and reciprocation (blue)(blue)5. Connector 5. Connector (black) (black) 6. Indirect retention.6. Indirect retention.
Reciprocals: Reciprocals: a part of the denture a part of the denture that resists the action of a clasp on a that resists the action of a clasp on a tooth as the denture is inserted or tooth as the denture is inserted or removed from the mouth.removed from the mouth.
Bracing (cont)Bracing (cont)
The lateral forces in particular are capable of inflicting considerabledamage on the periodontal tissues and alveolar bone in theedentulous areas.
Bracing on teeth may be achieved by means of rigid portions of clasp arms(1) or plates (2). Bracing on the ridges and in the palate is obtainedby means of major connectors and flanges (3).
Preparation of wax pattern for Co/Preparation of wax pattern for Co/crcrdenturedenture
Construction of a base metal alloy Construction of a base metal alloy frame for a RPDframe for a RPD
Prepare metal framePrepare metal frame
Study models with denture Study models with denture designs, master cast.designs, master cast.
Process and finish denturesProcess and finish denturesSetting the teeth and waxing
Key to Successful TreatmentKey to Successful TreatmentRisk estimation Good pre-operative planningAppropriate case selectionAppropriate treatment selectionGood prosthetic designPatient educationRecall and maintenance
QUIZQUIZa
b
c
d
e
SUMMARYSUMMARY
Choice of treatment depends :Choice of treatment depends :Type of caseType of caseCost of the treatmentCost of the treatmentMedical condition of the patientMedical condition of the patientMaterial available/Material available/expertiesexperties
Pre-operative Post-operative
Pre-operative Post-operative
References:References:British dental journal 2000 (RPD).British dental journal 2000 (RPD).A A ColourColour Atlas of Removal Partial Atlas of Removal Partial Denture. Davenport JC.Denture. Davenport JC.Oxford handbook of clinical dentistry, Oxford handbook of clinical dentistry, 19991999
