cosmetic dentistry - beauty & science

10 I I special topic _ porcelain laminate veneers retraction cord at this time. Finish the prepared tooth surfaces with a polishing disc and a white stone bur (Figs. 19a & b). Sixth, prepare for the impression by placing a second (thicker) retraction cord (Ultrapak Cord #1, Ultradent Products) and wait for five minutes. This second cord can be a single, continuous cord for easy removal. Right before the impression material is applied to the tissue, remove the second retrac- tion cord (Figs. 20a & b). I recommend using heavy and light body VPS material. The stump shade can betakenatthispoint(Fig.21).Youshouldmakesure that all retraction cords are removed before the patient is released. _Provisionalisation Interim veneers play significant roles, serving as a communication tool and a phonetic evaluation tool (Figs. 26a & b). Through these evaluations and discussionswiththepatient,achangemaybemade in the laboratory procedure for the final restora- tions. There are many materials for provisionalisation. I often use a direct method with bis-acryl or flow- able resin to make interim veneers. For the case illustrated here, I used an indirect method because it has several advantages, such as verification of the amount of tooth preparation and better control of interim veneer forms. First, make an alginate impression of the pre- pared teeth. You can use the silicone matrix and a PMMA resin to make acrylic interim veneers (Figs. 22a–c). After trimming, verify the thickness with a digital calliper (Fig. 23). Second,makeaspotetchingforretentionofthe interim veneers. Then apply a glazing resin coating (G-Coat Plus, GC) to the interim veneers for the cosmeticdentistry 2_2012 Fig. 35b Fig. 36a Fig. 36b Fig. 36c Fig. 34a Fig. 34b Fig. 34c Fig. 35a Fig. 32a Fig. 32b Fig. 33 Fig. 30a Fig. 30b Fig. 31a Fig. 31b