Porcelain onlays.

For years porcelain-fused-to-metal crowns have been the only restoration for posterior teeth in which strength and esthetics were important. Predictable results can now be achieved with a much more conservative approach--the bonded porcelain onlay. This article reviews the preparation designs as well as several types of materials currently available for the cosmetic onlay. An application using porcelain onlays to restore vertical dimension is explored. With this technique, moreover, the porcelain onlay is combined with porcelain veneer to achieve a functional and esthetic restoration.