Differing porcelain systems.

Current research in ceramics has centered on improving the strength, fit, and bondability of porcelain. Several different approaches to accomplishing these ends have led to the development of stronger cores, castable glass, computer-generated restorations, and chemically altered basic ceramics. Improvements in these basic parameters of clinical success have led to the use of all-ceramic systems such as inlays, onlays, conservative veneers, anterior and posterior crowns, and even fixed partial dentures. Porcelain veneers and full-coverage ceramic crowns have held up well clinically. Porcelain inlays and fixed partial dentures have presented problems with fit and strength, respectively, that may need correcting before they are clinically predictable in all situations. Nevertheless, it is apparent that modern dental porcelain technology has come a long way since it was originally introduced as an esthetic replacement for less cosmetic, metal-based restorations.