HistoryandDevelopmentofDentalimplantPreviousnon-integratingformsofimplantsmayhavebeenanchoredtobonebymeansofasurroundingsheathofpseudoperiodontalligament,butthisfibroussheathwasapoorlydifferentiatedlayerofscartissue.Inmostcases,loadingandgradualwideningofthisledtolooseningoftheimplantandsubsequentimplantfailure.第一頁，共十七頁。編輯課件ImplantsImplantsconsistofthreemainparts.ThethreecomponentsincludeImplant,abutmentandsuperstructure.第二頁，共十七頁。編輯課件Implants

Mostcontemporarydentalimplantsaremadeofcommerciallypuretitanium,whichhasbeenshowntohaveexcellentbiocompatibility.Titaniumisalightmetal.第三頁，共十七頁。編輯課件ImplantsWhenexposedtoair,asurfaceoxideisrapidlyformed.Thislayerofoxidedeterminesthebiologicalresponse.Commerciallypuretitaniumisalsohighlyresistanttocorrosion.第四頁，共十七頁。編輯課件ImplantsOthermetalshavebeenusedforosseointegration,includingzirconium,goldandtitanium-aluminium-vanadiumalloys.Thesealloysmaystrengthentheimplantbuthavebeenshowntohaverelativelypoorbone-to-implantcontact.第五頁，共十七頁。編輯課件ImplantsImplantdesignhasagreatinfluenceonthestabilityandsubsequentfunctionoftheimplantinbone.Themainparametersareimplantshape,implantlength,implantdiameterandsurfacecharacteristics.第六頁，共十七頁。編輯課件ImplantsRoot-formimplants,suchasscrewsandcylinders,arethedominatingimplantdesignstodays.Screwimplantsareconsideredtobesuperiortocylindricalonesintermsofinitialstabilityandresistancetocompressionandtensionstressesunderloading.第七頁，共十七頁。編輯課件AbutmentAdentalabutmentistypicallyamachinedorcustom-madecomponentthatconnectsthefinalprosthesistotheimplant.Theabutmentmaybemadefromavarietyofmaterials.第八頁，共十七頁。編輯課件AbutmentAmachinedabutmentistypicallymanufacturedfromtitanium,goldorceramic.Theadvantagesarethatitissimpletouse,requiresminimalchairsideandlaboratorytimeandhasapredictableprecisionfitandgoodretention.第九頁，共十七頁。編輯課件AbutmentAcustomisedabutmentmaybeprepable,custom-madeinthelaboratoryorcomputer-aideddesign-computer-aidedmanufacture(CAD-CAM)designed.Aprepableabutmentisgenerallysuppliedbythemanufactureasablankintitaniumorceramictobemodifiedbytheclinicianatthechairsideorbythedentaltechnicianonthemastermodel.第十頁，共十七頁。編輯課件AbutmentCustomisationinthelaboratorytypicallyinvolveswaxingtotherequireddesignandcasting.ACAD-CAM-designedabutmentisproducedwithspecialisedcomputersoftwareandamillingmachine.第十一頁，共十七頁。編輯課件AbutmentTheselectionanduseofanabutmentisdeterminedbyanumberoffactors,includingimplantangulationandorientation,depthofsofttissuefromimplantbodytogingivalcuff,aestheticdemands,interocclusalspaceandpreferenceforacementorscrew-retainedprosthesis.第十二頁，共十七頁。編輯課件SuperstructureAfinalprosthesisItmaybeconnectedtotheimplantThereareseveralwaystoconnectthefinalprosthesistotheimplant:screwretaineddirecttotheimplant;Screwretainedtotheabutment;Lateral/horizontalscrewretainedtoabutment;Cementretainedtoabutm