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cosmetic dentistry_ beauty & science

I 21 technique _ improving aesthetics I cosmeticdentistry 4_2013 In this procedure, the composite shells help to predict the shape and the final aesthetic outcome of the milling process. They also serve as a guide toestablishtheamountofreductionnecessarydur- ing tooth preparation. After the scanning process, the teeth were prepared using the composite resin shells as a reference to determine the amount of tooth reduction. A digital impression was taken (CEREC Bluecam) afterthepreparationshadbeencompleted.Thedig- ital image acquired after preparation was merged and correlated with the digital image taken with the anatomic composite shell in place to generate the proper shape of the permanent veneers to be fabricated(Figs.6a–e).Themillingprocesswasthen initiated using a CEREC III milling unit equipped with CEREC Software 4.0. After the milling process, the veneers were re- moved from the milling unit and visually inspected for potential flaws. The veneers were then tried-in, polishedwith0.6µdiamondpasteandsubsequent- ly placed with Variolink Veneer Medium Value 0 (Ivoclar Vivadent) using the adhesive technique ac- cordingtothemanufacturer’sinstructions(Figs.7a–c). In order to mask the dark shade of the tooth sub- strate, a staining agent (IPS Empress Universal Stains, Ivoclar Vivadent) was applied internally to each veneer prior to cementation. _Conclusion The concept of chairside CAD/CAM restoration differs from conventional dentistry in that the restoration is typically luted or bonded in place onthesameday,whereasconventionaldentalpros- theses of larger size, such as crowns, involve the placement of temporaries for several weeks while adentallaboratoryproducestherestoration.1 Asthe CAD/CAMrestorationisbondedonthesameday,the principles applied in predicting the final outcomes present unique challenges compared with conven- tional clinical procedures for any aesthetic treat- ment. The clinical case described here presented some limitations, as can be seen in the slight bulki- ness of the final restorations and the straighter in- cisal edges of the two central incisors (Figs. 7a–c) compared with the composite shells (Figs. 3d–f). These differences were attributed to a software limitation, as no other anatomical/morphological modificationwasperformedafterthemillingprocess had been completed. However, the final outcome using monochromatic blocks was acceptable and the clinical sequence presented here using AST shows a very simple and innovative way to predict the final outcome of an aesthetic treatment and suggests that CAD/CAM technology is a very attractive con- cept when one understands the materials science, machine capability and the limitations involved._ Editorial note: A complete list of references is available fromthepublisher. merged and correlated with the digital image taken with the anatomic composite shell (b) in place to generate the proper shape (c & d) of the permanent veneers to be fabricated (e). Figs. 7a–c_Photograph of the completed clinical case (a). The final texture produced by the milling machine (b & c) and the quality of the aesthetic result are satisfactory despite the use of a monochromatic ceramic block. The texture matches that of the buccal surface of the Hajto model (Fig. 2a) that was selected for this clinical case. Fig. 7c Nelson RFA Silva,DDS,MSc,PhD (Federal University of Minas Gerais,Belo Horizonte), is an assistant professor at the NewYork University College of Dentistry. Tel.:+55 31 8949 2405 nrfa.silva@gmail.com Paulo Kano,DDS, is enrolled for an MSc and is in private practice in São Paulo in Brazil. Eric Van Dooren,DDS, is a visiting professor at the University of Liège and is in private practice in Belgium. Cristiano Xavier,DDS, is a professional photographer in Belo Horizonte in Brazil. Jonathan L.Ferencz,DDS, is a clinical professor at the NewYork University College of Dentistry in the USA and in private practice in NewYork. Emerson Lacerda,CDT, works in a laboratory in São Paulo. cosmeticdentistry _about the authors Fig. 7a Fig. 7b