Superstructures for single-tooth implants

Inmoderndentalimplantology,aestheticsarebecomingincreasinglyimportant.Improvedaestheticresultscanbeachievedasaresultofthewidervarietyofmaterials,designsandtechniquesavailableforimplantrestorationstoday.Thereisalsoawiderselectionofimplantabutments,includingCAD/CAM,UCLAandprefabricatedabutmentsmadeofdifferentmaterialssuchaszirconia,titaniumandgold.Thisarticledescribessingletoothimplantcasesinwhichaestheticsuperstructuresweresuccess-fullyfabricatedwiththeIPSd.SIGN■layeringceramicsystem.Inordertoachieveanaturalshapeandcontourofimplantrestorations,profoundknowledgeoftheanatomyofteethandthegingivaloutlineisnecessary.Acarefulexaminationofthehorizontalsectionsofteeth(Fig1)revealsthateachsectionisuniqueandhasadifferentappearance.Ceramistsshouldconsidertheseuniquecharac-teristicsofdentalanatomyinordertoachieveanaturalemergenceprofilewhichisinharmonywiththatoftheadjacentteeth(Fig2).Acustomizedabutment(UCLAabutment)mustmimictheshapeandcontourofthenaturaltooth.Inthiscase,theabutmentwascastingoldandaceramicshoulderwasappliedusingIPSd.SIGNmaterials(Fig3).Inordertoensureanatural-lookinggingivaloutline,thegingivalcontourontheworkingmodelhadtobemodified(Fig4).Afterthefabricationofthecustomizedabutment,themetalframeworkwascreatedbasedonareducedfull-contourwax-up(Figs5and6).PriortoveneeringwithIPSd.SIGNlayeringmaterials,thesurfacesofthemetalframeworkswerecarefullyfinishedusingcrosscuttungstencarbideorceramic-bondedburs.Afterhavingblastedtheframeworkswith100μaluminiumoxideattwobarpressureandsteam-cleaningthem,theywerereadyforthefirstwashfiringortheactualopaquerfiringcycle(Figs7and8).Followingthis,thefluorapatiteglassceramicmaterialswerebuiltup.Aftercontouringandfinishing,surfacetexturewasapplied.Finallytherestorationwasglazedandpolished.ThisisonlybrieflyshownherebymeansoftheFigures9to18.SummaryWhenfabricatingrestorations,itisimportanttoimitatethefeaturesofnaturalteeth.Therootandtheshapeinthecervicalarearequireparticularattentionwhenimplant-bornerestorationsaremade.Never-theless,thefabricationofimplant-retainedrestorationshasbeendifficulttodate,asthemetalimposescertainlimitations.Fortunately,anumberofmanufacturershavedevelopednewmaterialswhichopenupnewpossibilitiesandthusenableresultstobeachievedthataresatisfactoryforallthepartiesinvolved.InparticulartheIPSd.SIGNmaterialsprovideoutstandingpropertieswhichallowthenaturaltoothshadetobepreciselymimicked(Figs19and20).Consequently,thefabricationofaestheticallypleasing,implant-supportedrestorationshasbecomeconsiderablyeasier,assuitablematerialsareavailableforeachindividualcase。