Bond strength of CAD-CAM and conventional veneering materials to different frameworks

New materials and precise manufacturing processes allow for new processes in the veneering and production of fixed dental prostheses. However, data on the bond strength of computer-aided design and computer-aided manufacturing (CAD-CAM) and conventional veneering materials to substrates bonded with different composite resins are lacking. The purpose of this in vitro study was to investigate the shear bond strength (SBS) of 2 CAD-CAM, Lava Ultimate (LVU) and VITABLOCS Mark II (VMII), and 3 conventional veneering materials (VM9, VM13, VTI) to 3 different substrates: zirconia (ZIR), cobalt-chromium (CC), and titanium (TIT). Substrates and veneering cylinders were manufactured and bonded by using 3 different composite resins, RelyX Unicem (RUL), RelyX Ultimate (RXU), and Sinfony (SIN), after various pretreatments (n=18). Half the specimens underwent artificial aging before SBS testing, and failure types were analyzed. Univariate 1-way ANOVA, Kruskal-Wallis, and Mann-Whitney U were computed (α=.05). CC substrates bonded with RUL showed the highest SBS (P=.007). ZIR substrates bonded with RXU presented higher SBS than TIT substrates (P=.007). ZIR substrates bonded with SIN showed higher SBS than CC substrates (P