CAD/CAM Magazine

38 I I trends _ digital datasets _The annual meeting of the German Society of Dentistry and Oral Medicine (DGZMK), held in conjunction with the Society for Dental Ceramics (AG Keramik),theDGZMK’sprofessionalsociety,isamajor event that critically examines experiences with all- ceramics and CAD/CAM methods in clinics and prac- tices. At this year’s meeting, the 10th AnnualCeramic Symposium,ProfBerndWöstmann,HeadofProstho- dontics at the University of Gießen in Germany, fo- cusedinhispaperontheprogressthathasbeenmade inthedigitisationofintraoralimpression-taking. Naturally, perfectly fitting restorations that can be seated without further correction are every dentist’s wish.Thisrequiresexactimpressionsofthepreparation anddentalarch.Quitesometimeago,digitisationmade inroadsintothisdiscipline,beginningin1985withthe first digital impressions by Prof Werner Mörmann at theUniversityofZürich.ProfWöstmannexplainedthat enroute to an exact restoration, creating an image of theintraoralsituationeitherasarealoravirtualmodel is a very crucial step—it is only possible to produce the final restoration indirectly, whether it is an inlay or amulti-unitfixeddentalprosthesisbridge(FDP). Owing to material and haptic conditions, it is still impossibletoproducea“flawless”conventional(stone) model from classical impressions with elastomeric im- pressionmaterial.Everyvirtualmodelproducedonthe basisofaclassicalimpressionisinexact,regardlessofthe accuracyofthescanningprocedureitself.Itthusmakes sensetoperformscanningdirectlyintheoralcavity. CAD/CAM 2_2011 Fig. 1_Short-wave blue light with structured light projection. (Photo courtesy of Ender) Fig. 2_Single images are matched to create a digital full-arch model, basis for construction and milling of the framework. (Photo courtesy of Mehl) Fig. 3_Optoelectronic intraoral scan using the C.O.S. Lava system. Crown preparation and preparation margin are portrayed exactly. In addition to framework manufacture, the dataset enables production of an SLA resin model including the antagonist teeth. Fig. 4_Intraoral scan (C.O.S. Lava) of a molar with a cusp-supported Intraoral impression-taking: Digital datasets soon to catch on everywhere Author_ Manfred Kern, Germany Fig. 1 Fig. 3 Fig. 4 Fig. 6Fig. 5 Fig. 2