All-ceramic restorations: classification and clinical evaluations.

In the search for alternative and esthetic restorative materials, many all-ceramic systems have been introduced for the general practitioner. They are used as veneers, inlays/onlays, crowns, and as enamel/dentin bonded partial or total coverage without macroretention. This article describes a classification of the different commercial all-ceramic systems and gives a review of their clinical durability. Reasons for failures are given for the different restorations. Fracture is the main reason for failure, especially for all-ceramic crowns and inlays. The frequency of secondary caries contiguous to resin composite luted ceramics is very low. Wear of the luting agent, called ditching, is not an enduring clinical problem. The use of certain ceramic materials as well as luting agents have been shown to be contraindicated, especially in molar teeth. Newer reinforced ceramics showed better durability then the earlier fired ceramic reconstructions.