Dentists have searched for the ideal restorative material for more than a century. Although direct restorative materials such as amalgam, composites, and restorative cements have been used with reasonably good success during the past several decades, but they are not feasible for multiunit restorations. In this regard a restorative material should be biocompatible and durable, and it should maintain its surface quality and esthetic characteristics over an extended period of time, preferably for the lifetime of the patient. Dental ceramics consist of silicate glasses, porcelains, glass ceramics, or highly crystalline solids. They exhibit chemical, mechanical, physical, aesthetic and thermal properties that distinguish them from metals, acrylic resins, and resin-based composites. The use of all ceramic prosthesis in restorative treatments has become popular and many of these restorations can be fabricated by both traditional laboratory methods and CAD/CAM machination. The objective is to review the state of the arts of CAD/CAM all-ceramic biomaterials.
