cosmetic dentistry_ beauty & science

I have a CEREC machine that works especially well for a single veneer. Six or eight veneers can be done on the CEREC, but this is then rather time consuming. Two or three cases of the samenumberofteethcouldhavebeenprepared, impressions taken and sent to a laboratory in the same period. It is more cost effective to use a laboratory but you have to have the best lab- oratory available to you if you expect perfect results. Feldspathic porcelain is the only material that willlooknatural.Pressedceramicswilllookmore opaque,somewherebetweenaporcelain-fused- to-metal restoration and a natural tooth. For patients requesting brilliant white, feldspathic porcelain can work well too and one can adjust the colour by the bonding composite used under the veneer. Very little shade adjustment can be done under pressed ceramic porcelain. Flowable com- posites work the best and come in many shades, which makes shade adjustments easy. The flow- able composite by Kerr has the right consistency forveneersandwithOptiBondSolothecompany offers the strongest bonding agent. The preparation requires only a little more than 0.5 mm of reduction so that it does not go through the enamel, if possible. The bond is the best on enamel. There should be the same reduction over the total facial surface for the laboratory to make a perfect veneer. Cut three or four depth grooves of 0.5 mm then remove the enamel to the grooves. If instant orthodontics is the treatment plan, some teeth may need to be reduced more and others less. Run the preparation interproximally from gingival to incisal to hide the margin visu- ally, but do not break the contact point. The gingival margin should be at the gingival crest or a little below. It should have a chamfer for ease of finishing, precluding any chipping at the margin. Some dentine will show through at the gingival margin because the enamel is less thick there. If there is room, insert a thin piece of gingival braid, which can be left there during the impression. Reduce the incisal by approximately 1 mm so the finish line is on the lingual, and round the incisal-facial junction so that there are no potential fracture lines in the veneer. When the veneers come back from an ex- cellent laboratory there should be little or no adjustments necessary before bonding them to the teeth. Etch them with hydrofluoric acid gel for at least three minutes. Rinse them thorough- ly, neutralise them with a baking-soda slurry and I 07 case report _ veneers I cosmeticdentistry 4_2011 Fig. 3bFig. 3a Fig. 4bFig. 4a