Complete and partial contour zirconia designs for crowns and fixed dental prostheses: a clinical report

Since the introduction of milled zirconia copings for ceramic crowns, a variety of techniques have been introduced to reduce the incidence of chipping or fracturing of the porcelain veneer. These include methods of improving the interface between the coping and the veneer, reducing thermal incompatibility between the two, and optimizing the coping design to minimize tensile loading on the porcelain. Another method of reducing porcelain chipping and fracture is to limit or eliminate the porcelain coverage of zirconia copings and frameworks. Even though patients often demand tooth colored or nonmetallic restorations, they tend to be less concerned with the optimal esthetics of their posterior teeth. This article describes 4 representative clinical situations where efforts were made to minimize or eliminate porcelain coverage on posterior zirconia crowns and a fixed dental prosthesis, while still achieving acceptable, but not optimal, esthetics.