ABSTRACT
Bond strength between veneers ceramic any zirconia framework is the weakest component in the layered structure. This bond was sensitive to the liner application and type of veneer ceramic. This study examined the core-veneer microtensile bond strength of a CAD/CAM [computer aided design/computer assisted manufactured] zirconia ceramic by comparing two ceramic veneers with and without liners. Disc-shaped [19.4x3.5mm] specimens were fabricated using CAD/CAM zirconia core materials [Cercon]. Half of the discs were left white and the others were colored with an A2 liner. The specimens were veneered with Ceram Kiss or Zirkonzahn ICE veneering ceramics [3.5 mm]. The discs were then cut into microbars [CC, ZC, CW, ZW] and the microtensile strength of the core-veneer bond was calculated. The specimens were analyzed by SEM and the data were compared using one-way ANOVA and Post hoc tests. The type of veneering ceramic [Ceram Kiss] and liner application [coloring] significantly affected the core-veneer microtensile bond strength [P<0.0001]. The Zirkonzahn layer [ZC, ZW] did not show significant differences [P=0.08]. Careful selection of veneering ceramics and liner applications can be recommended as they have significant roles in microtensile bond strength of core veneered restorations