24 - Dental glass-ceramics

Abstract

Regarding the development of biomaterials for dental applications, special prerequisites must be met. The focus here is on dental restorative materials, that is, materials with which to restore the natural tooth structure. Typical products in this area of biomaterials are dental inlays, onlays, veneers, and bridges. In contrast to bioactive materials, which bond to living bone, restorative material should possess high chemical durability, mechanical strength and toughness, and should exhibit optical properties that mimic the natural tooth microstructure so that the restorations are aesthetically pleasing. Glass-ceramics permit all these properties to be united within one material. The mechanisms of controlled nucleation and crystallization of glasses have been applied to develop both glass-ceramics as veneering material for metal dental restorations and glass-ceramics as metal-free dental restorations. The metal-free restorations were developed as leucite-type glass-ceramics by controlled surface nucleation and crystallization and lithium disilicate glass-ceramics applying the heterogeneous internal nucleation and crystallization mechanisms. The clinical successful application of leucite-type glass-ceramics is concentrated on dental inlays, crowns, and veneers. The lithium disilicate glass-ceramics veneered with an apatite containing glass-ceramics are used as single unit biomaterials or small dental bridges. The apatite glass-ceramic is also applied as veneering material for ZrO 2 bridges.