The diversity of dental ceramics continues to stimulate laboratory and clinical research. Systems such as Dicor and Empress are now established, and data regarding the in vitro and in vivo performance of such restorations have been reported widely. Modifications to several systems have been suggested or introduced to overcome certain disadvantages. The potential of the In-Ceram system remains to be exploited to the full. The diversity and sophistication of some of the CAD-CAM systems may prove to be influential in the future. Each system has its own merits, but may also have shortcomings....