cosmetic dentistry - beauty & science

16 I I special topic _ veneers enables dentists to limit much of the veneer preparation to enamel, thereby reducing the risk of overexposing dentine. _Clinical preparation After the patient had accepted the treatment plan, the dental technician created a diagnostic wax-up. In order to observe the principles of conservativepreparation,apurelyadditivetech- nique was used. Wax was added to the model to build up the new tooth forms. A resin matrix (mock-up) was then created from the diagnos- tic wax-up to allow the patient to preview the restorations prior to tooth preparation. After patient approval, the mock-up was used as a blueprint for enamel reduction. The patient was anesthetised and depth cuts were placed in the incisal and cervical third of the matrix. Proper depth cuts were made with a diamond bur, using the matrix as a guide. The cuts were marked with a pencil for easy identification. The mock-up was removed and the necessary dental enamel for the veneer preparations was removedusinglargeround-endeddiamondburs (Fig. 2). Finally, the preparations were checked with vertical and palatal putty stents. These stents had been created previously from the diagnostic wax-up to ensure that the preparations were compatible with the veneer shape. The provi- sional restorations were inserted and checked. Particular emphasis was given to the embrasure form, where a space was left to allow the gin- gival tissue to recover fully after placement. The provisionals were spot-etched with phos- phoricacidsolutionandlutedwithresincement. The patient returned after a few days, a facebow was created, and the case was sent to the dental ceramist (Fig. 3). _Laboratory procedure The veneers were built up on the refractory dies using the IPS d.SIGN porcelain (Fig. 4). Prior to the actual layering procedure, margin ma- terial was applied in a thin layer as far as the margins and baked. Fig. 10_After thermal glazing, the restorations were mechanically polished. Fig. 11_The delicate ceramic veneers already looked impressive on the model. Figs. 12 & 13_The seated restorations. cosmeticdentistry 2_2012 Fig. 10 Fig. 11 Fig. 12 Fig. 13