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ePaper created 2018-01-31, 10:01:59 | version 1.38.0
| case report Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Case report (Figs. 5–32): Fig. 5: Frontal view pre-operation. Fig. 6: Frontal smile view pre-operation. Fig. 7: Upper-anterior dentition view pre-operation. Fig. 8: Upper jaw view pre-operation. Fig. 9: DSD dentition view pre-operation. Fig. 10: DSD smile view pre-operation. Case report A 57-year-old female patient presented, whose denti- tion had apparent colour changes and abrasions that had occurred gradually over time. These problems resulted in an unaesthetic smile and made her appear older than her age. She also made a request for a highly comfortable and minimally invasive treatment plan, and expected an improvement in the colour and shape of her upper ante- rior teeth, which would rebuild her smile and self-confi- dence (Figs. 5 & 6). It was found that due to the abrasion which had occurred over several decades, the labial surface was plane and flat, the incisors had been worn to a straight line and also had abrasion-associated defects (Figs. 7 & 8). The no-prepa- ration veneer that would occupy the “outer space” of the teeth would eliminate the slight wrinkles around the lips. These effects were part of the patient’s expectations and the treatment plan was accepted. Taking the treatment requirement and oral condition into consideration, the patient was prepared for the ul- trathin no-preparation veneer. Digital Smile Design (DSD) was done based on the pre-operation photos (Figs. 9 & 10), and the patient was satisfied with the aesthetic ap- pearance of the design. The patient wanted her teeth colour to seem natural and to disguise the discoloration. The treatment plan was confirmed as CEREC designed and manufactured Mark II (VITA) veneer of 0.3 mm thickness, 1M1 shade, and the material was cho- sen for its excellent aesthetic performance and translucency. The manufacture of no-preparation veneer could de- pend on the precise wax-up of pre-operation. This step could save the patient’s chairside waiting time; the bio- copy technique can simplify the design process; milling the restoration with a 0.5 mm original thickness and pol- ishing after milling will decrease the risk of milling defect. The exact process can be concluded as: 1. Obtain a precise pre-operation impression, and make the model. Use a CEREC scan to obtain information about the abutment teeth (Figs. 11 & 12). 2. Depending on the DSD result, make a wax-up on the pre-op model. The thickness of wax-up should be from 0.3 mm to 0.5 mm. Get the biocopy scan of the wax-up model, and match accurately with the pre-op model (Figs. 13–15). 3. Setting the margin of the abutment teeth, the marginal edge line is not fixed because of the no-preparation tech- nique. The direction of insertion should be defined first, which can cover most areas of the labial surface, incisor edge and adjacent surfaces. The border of the covered area should be the margin of the restoration (Fig. 16). 4. Shape formation of the restoration: Copy the target shape of the biocopy model, the restoration should be calculated automatically. If there is any defect, it can be adjusted and corrected by the tools. If there are any areas not thick enough for 0.5 mm, it should be added to 0.5 mm to avoid fractures during the milling process (Figs. 17 & 18). 5. Modification and polishing of the initial restoration to 0.3 mm thick after milling. And fine polishing of the final restoration (Figs. 19 & 20). 6. Intraoral try-in, fine adjustment and cementation (Figs. 21–24). 18 CAD/CAM 1 2018