I clinical technique _ smile design Fig. 8_Upper preparations and preparation shade. Figs. 9a–10c_Upper and lower indirect provisionals on instant silicone models. Fig. 8 Fig. 9a Fig. 9b Fig. 10a Fig. 10b Fig. 10c First, the instant silicone model was lubricated with a water-based lubricant (such as KY Jelly). Next, the putty matrix was filled with bis-acryl and then placed onto the silicone model. After a minute and a half, the provisional was set up and ready to be trimmed. Because this method of temporisation involves a quick way to make a model of the prepared teeth, the provisional can be trimmed and polished in the laboratory. Finishing provisionals in this manner is much more accurate, as well as kinder to and easier for the patient, and particularly the gingival and the prepared and impressed teeth (Figs. 9a–10c). In order to prepare the gingiva for the final impressions, Expasyl (Kerr) was placed around the gum line. Final impressions with a PVS material (examples are Take 1 Advanced, Kerr; and Virtual, Ivoclar Vivadent) were then taken in custom trays. A slow-setting material was used to record her bite registration (SuperDent). In order to cement the provisionals, the same bis-acryl was placed in the temporaries and seated in the mouth. The excess was removed with a microbrush before the material set. The patient loved the way her provisionals looked and fitted (Fig. 11). There were no surprises, as she had chosen the smile design she liked best before any work had even begun. When she returned for the final porcelain restorations, the patient was concerned that they might not look as good as her provisionals. Because the minimal preparation was all in enamel, we could try the restorations with no anaesthetic and no discomfort. This is important to allow the patient to gain a true feel of the teeth, especially when length is being increased. We assured her that we would try-in the restorations and gain her approval before seating them permanently. Thus, we invited her entire family to the seating appointment in order to offer their opinions. As is often the case, it was especially important to please one family member in particular, and for this case it was her daughter. For the try-in, we used different shade combinations of try-in pastes in order to determine what looked the most natural. I call this the mix-to-match method. This method is especially important for extensive cases with multiple types of restorations and porcelains. In this case, feldspathic porcelain was 20 I cosmetic dentistry 4_ 2009