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Implant-AssistedRemovablePartialDenturesAaronOmura,DMD,MDS,CDT([email protected])
Advantages
• Esthetics:1) Attachmentsadjacenttodistal-mostteethmaypermit
eliminationofclaspsandimprovementinesthetics3,8,9• Function:1) Increasedsupportandstability3,8,9,102) EliminateKennedyClassI&IIsituationswithimplant
placementbeneathmostdistaltooth8,93) Favorablefunctionalloadtransferandincreasedcross-
archstabilization3,8,94) Occlusalstability3,5,9
• Comfort:1) Flangelengthmaybeshortenedduetoincreased
supportandstability82) Extensiontotuberosityandretromolarpadmaybe
removedwitheliminationofdistalextension83) Potentialforincreasedretention3,9,10
Disadvantages
1) Surgicalinterventionisnecessary2) Accuracyofimplantplacementiscrucial63) Increasedtreatmentcomplexity&cost34) Additionaltreatmenttimenecessary10
IARPDConsiderations
Diagnosis&TreatmentPlanningAfteraproperdiagnosticexamination,athoroughunderstandingofpropertoothpositioningtosatisfyfunctionalandestheticdemandsisnecessarytominimizefuturecomplicationsandobtainidealresults.Thisisaccomplishedviaadiagnosticmounting,diagnosticwax-upandeventualtoothtry-intoverifyesthetics.Onlywhenestheticandfunctionaldemandshavebeenmet,canimplantplanningtakeplace10.WiththehelpofCBCTimaging,potentialimplantsitescanbevisualized3-dimensionallyrelativetothedesiredtoothpositionsandcontours.Implantsitestoaidesthetics,function,andcomfortcanbeevaluatedwithanatomicandbiomechanicconcernsinmind10.Restorativespace(≈10mm)canbevisualizedrelativetoscannedprototype(3.5mmLocator+housing,2mmresin,1mmmetal,2mmteeth)2.Lastly,implantsmustbeplannedparalleltodeterminedpathofplacementifstudattachmentsaretobeused.AbutmentsIfattachmentsaretobeused,guideplanesmustbemadeparalleltoimplanttrajectoryforproperengagementofattachments3,4,8.Inclasplessdesigns,itmaybeprudenttoincludeadditionalrestsandundercutsasacontingencyplanintheeventofimplantfailure10.FrameworkDesign(AlltraditionalRPDconceptsstillapplytoIARPDS)8Aftermastercastshavebeenfabricatedandmounted,teethshouldbesetforestheticsandfunction.Matricescanthenbefabricatedtocapturetoothpositionsandaidinframeworkdesigntomaximizesupportwithoutinfringingonrestorativespace1,8,10.Astrutofmetal“overthetop”ofimplantattachmentsisrecommendedtominimizestressandpotentialfractureinthoseareas11.Maintenance
Naturalteeth,periodontium,peri-implanttissuesandedentulousridgesshouldbeexaminedforhealthandstability.Occlusionshouldbeevaluatedforstability/wearandmanagedappropriately.Implantabutmentsandattachmentsmustbecarefullyinspectedforwear/damagetoensureoptimalperformance10.
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Procedure:DigitalTransferofSurveyLineforiRPDImplantPlanning1.Makeprimaryalginateimpressionstogeneratediagnosticcasts.
2.Duplicatediagnosticcastsusingreversiblehydrocolloid(InstalloidDuplicatingMaterialAll-Purpose,CMPIndustries,Inc.)Duplicatecastsmustremainuntouchedthroughoutprocedure.
3.Fabricateresinrecordbases(Triad,DentsplyInternationalInc.)andwaxocclusalrimstoprescribeddimensions.12Recordbasesmustbetransferrabletountouchedduplicatesforlabscanninglater
4.MakeinterocclusalrecordsincentricrelationattheplannedOVDusingvinylpolysiloxaneregistrationmedium(Regisil,DENTSPLYInternationalInc.).Makeafacebowrecordandmountindexedcastsinanarticulator(WhipMix2340,WhipMixCorporation).
5.Surveydiagnosticcastsandduplicateddiagnosticcaststothedesiredtilt.Completediagnosticwaxuptodesiredcontoursanddimensions.Setteethoccupyingedentulousspacesonresinrecordbasesfabricatedinstep3.
6.Evaluateestheticsandphonetics.Verifyocclusionanddiscusspatientacceptanceoftooth
arrangementatthewax-tryinappointment.
7.Drillarecesslargeenoughtooccupysurveyorientationrod(SOR)intotonguespaceorpalate
ofuntouchedduplicatecast.Arrangeduplicatecasttodeterminedtiltandlockthesurveytable.
8.Usingthesurveyor,lower(SOR)intorecessandlute(SOR)intoplacewithresin(GCPattern
Resin).Allowresintofullypolymerizebeforedisconnecting(SOR)fromsurveyorarm.
9.Usingalaboratoryscanner(NobelProceraScanner),scanduplicatecastwith(SOR)inplace.
Checktomakesure(SOR)iscapturedaccuratelyinscan.NowaddresinrecordbasewithwaxedprostheticteethandscanagaintocreatealayeredSTLfile.
10.TakeaCBCTonpatienttogenerateaDICOMfileofthedesiredarch/archesforimplant
planning.Then,importDICOMandSTLfilesintoimplantplanningsoftware(NobelClinician)andallowsoftwaretooverlaythetwodatasets.
11.Planimplantsparallelto(SOR)instrategicimplantpositionstofacilitateimprovedRPDfunction/esthetics.Allthewhilebeingconsciousofanatomicstructures,restorativespace,andsoundRPDprinciples.Overlaydiagnosticwaxup.
12. Incaseswherebonedoesnotallowparalleltrajectory,leaveimplanttoserveaslocal
reference.Insertandalignimplant,addappropriateanglecorrectingabutment,andparallelscrewaxistoreference
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13.Onceplanisverifiedtobesoundprostheticallyandsurgically,orderCAD-CAMtooth-bornesurgicalguide
14.Placeimplants,allowforproperhealingandcontinueIARPDfabricationasnormal.
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8. SchneidTR,MattiePA.Implant-assistedremovablepartialdentures.In:PhoenixRD,CagnaDR,DeFreestCF,eds.Stewart’sClinicalRemovablePartialProsthodontics.4thed.HanoverPark,IL:Quintessence;2014:259-277.
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10. OmuraAJ,LattheV,MarinMM,CagnaDR.Implant-assistedremovablepartialdentures:practicalconsiderations.GenDent.2016Nov-Dec;64(6):38-45.PMID: 27814254.
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