CAD/CAM - international magazine of digital dentistry

32 I I industry report _ anatomic shell technique or diagnostic casts were used during the treatment planning and clinical procedures. The entire aes- thetic treatment plan relied upon imaging (includ- ing photographs), prefabricated Hajto models3 and dental digital technology (CEREC AC with Bluecam, Sirona—CEREC Software 4.0). _Description of the anatomic shell technique The digital smile design protocol4–8 was used to determine the aesthetic needs of the patient. The patient, with the dentist’s assistance, selected the shapes of the teeth that best suited him using digital photographs of natural smiles from a com- puter smile library. After determining the ideal shapes and sizes from the digital smile design database, Hajto mod- els3 were selected based on the previously deter- mined tooth dimensions of the patient. Subse- quently, a silicone index (Virtual, Ivoclar Vivadent) wasproducedfromthelabialsurfaceoftheanterior teeth of the Hajto model that best matched the patient (Figs. 2a & b). Hajto models are replicas of the ideal natural anterior dentition of males and females, with examples of different tooth shapes, sizes and surface textures. _Composite resin shells A light-cured flowable composite resin (Tetric EvoFlow IvoclarVivadent)wasthencarefullyplaced into the index to produce very thin composite shells that duplicated the shape of the model teeth. After complete polymerisation, the composite shells were gently placed intra-orally on the labial sur- faces of the teeth and adjusted to obtain the best possible fit (Fig. 3a). Once the best anatomic resin shell position was obtained, the shells were polished and luted with- out acid etching using flowable composite (Tetric EvoFlow, Ivoclar Vivadent) (Fig. 3d-f). Thecliniciantogetherwiththepatientevaluated the aesthetic outcome with the polished composite shells in place (Fig. 3d–f). Digital photographs were taken to analyse the symmetry between the teeth andthepatient’sface.Followingthedigitalimaging analyses, small adjustments were performed at the interproximal embrasures. After completion of theaestheticmodificationsandpolishingsteps,the patient was asked to give permission to proceed with treatment for his new smile (Fig. 4). _Digital imaging In order to facilitate the digital image capturing process, CEREC Optispray powder (Sirona; Fig. 5) wasappliedinthepatient’smouthtocoattheteeth restored with the composite resin shells. An intra- oral scanner (CEREC Bluecam) was then used to create a 3-D digital model of the full mouth with the temporary composite resin shells. Fig. 4_Initial photographs with composite shells temporarily cemented in place. The shade difference of tooth 11 is due to the dark substrate showing through the composite veneer. Fig. 5_CEREC Optispray powder was applied in the patient’s mouth to coat the teeth fitted with the polished anatomic composite resin shells. Figs. 6a–e_A digital impression was taken after tooth preparation. The image shows the procedure for tooth 22 (a). The digital image acquired after preparation was CAD/CAM 2_2013 Fig. 5 Fig. 4 Fig. 6c Fig. 6d Fig. 6e Fig. 6a Fig. 6b