The bonding mechanism between zirconia framework and veneer ceramics and affecting factors

Abstract All-ceramic restorations are preferred in fixed prosthodontics treatments as a result of increasing esthetic expectations. Zirconium-oxide based ceramics offer advanced esthetic and mechanical features, bio-compatibility, decreased plaque accumulation and low thermal conductivity. Zirconia-based restorations are considered to be an alternative treatment method to conventional metal ceramic restorations. However it is known that zirconia based ceramic has increased opacity due to its high crystalline content. Esthetic expectations limited the monolitic usage of zirconia and require veneering with a ceramic which has optimal colour and transluceny. The bond strength between zirconia and veneering ceramic is affected by the factors like surface treatments applied on zirconia cores, the mechanical properties of veneer ceramics and the application methods of ceramics. But the bonding mechanism between zirconia and veneering ceramic is still unknown. This article offers a review of the literature about the factors affecting the bond strength between zirconia cores and veneer ceramics ceramics and their bonding mechanism