HistoryandDevelopmentofDentalimplantPreviousnon-integratingformsofimplantsmayhavebeenanchoredtobonebymeansofasurroundingsheathofpseudoperiodontalligament,butthisfibroussheathwasapoorlydifferentiatedlayerofscartissue.Inmostcases,loadingandgradualwideningofthisledtolooseningoftheimplantandsubsequentimplantfailure.第一页,共十七页。ImplantsImplantsconsistofthreemainparts.ThethreecomponentsincludeImplant,abutmentandsuperstructure.第二页,共十七页。ImplantsMostcontemporarydentalimplantsaremadeofcommerciallypuretitanium,whichhasbeenshowntohaveexcellentbiocompatibility.Titaniumisalightmetal.第三页,共十七页。ImplantsWhenexposedtoair,asurfaceoxideisrapidlyformed.Thislayerofoxidedeterminesthebiologicalresponse.Commerciallypuretitaniumisalsohighlyresistanttocorrosion.第四页,共十七页。ImplantsOthermetalshavebeenusedforosseointegration,includingzirconium,goldandtitanium-aluminium-vanadiumalloys.Thesealloysmaystrengthentheimplantbuthavebeenshowntohaverelativelypoorbone-to-implantcontact.第五页,共十七页。ImplantsImplantdesignhasagreatinfluenceonthestabilityandsubsequentfunctionoftheimplantinbone.Themainparametersareimplantshape,implantlength,implantdiameterandsurfacecharacteristics.第六页,共十七页。ImplantsRoot-formimplants,suchasscrewsandcylinders,arethedominatingimplantdesignstodays.Screwimplantsareconsideredtobesuperiortocylindricalonesintermsofinitialstabilityandresistancetocompressionandtensionstressesunderloading.第七页,共十七页。AbutmentAdentalabutmentistypicallyamachinedorcustom-madecomponentthatconnectsthefinalprosthesistotheimplant.Theabutmentmaybemadefromavarietyofmaterials.第八页,共十七页。AbutmentAmachinedabutmentistypicallymanufacturedfromtitanium,goldorceramic.Theadvantagesarethatitissimpletouse,requiresminimalchairsideandlaboratorytimeandhasapredictableprecisionfitandgoodretention.第九页,共十七页。AbutmentAcustomisedabutmentmaybeprepable,custom-madeinthelaboratoryorcomputer-aideddesign-computer-aidedmanufacture(CAD-CAM)designed.Aprepableabutmentisgenerallysuppliedbythemanufactureasablankintitaniumorceramictobemodifiedbytheclinicianatthechairsideorbythedentaltechnicianonthemastermodel.第十页,共十七页。AbutmentCustomisationinthelaboratorytypicallyinvolveswaxingtotherequireddesignandcasting.ACAD-CAM-designedabutmentisproducedwithspecialisedcomputersoftwareandamillingmachine.第十一页,共十七页。AbutmentTheselectionanduseofanabutmentisdeterminedbyanumberoffactors,includingimplantangulationandorientation,depthofsofttissuefromimplantbodytogingivalcuff,aestheticdemands,interocclusalspaceandpreferenceforacementorscrew-retainedprosthesis.第十二页,共十七页。SuperstructureAfinalprosthesisItmaybeconnectedtotheimplantThereareseveralwaystoconnectthefinalprosthesistotheimplant:screwretaineddirecttotheimplant;Screwretainedtotheabutment;Lateral/horizontalscrewretainedtoabutment;Cementretainedtoabutment第十三页,共十七页。第十四页,共十七页。第十五页,共十七页。第十六页,共十七页。内容总结HistoryandDevelopmentofDentalimplant。Superstructure。Afinalprosthesis第十七页,共十七页。