Shear bond strength of vat photopolymerization additive‐manufactured zirconia to veneering ceramic

Abstract Purpose To evaluate the shear bond strength (SBS) of stereolithography (SLA), digital light processing (DLP) manufactured, and computer numerical control (CNC) milled zirconia to veneering ceramic. Materials and Methods Rectangular shaped zirconia substrates (10 × 5 × 5 mm 3 ) were manufactured through SLA, DLP, and CNC technology separately. Their surface roughness was measured and the surface topography was analyzed by atomic force microscope (AFM). Then the veneering ceramic (5 × 5 × 5 mm 3 ) was applied to carry out the SBS test. Failure modes were examined by a scanning electron microscope (SEM). The data of SBS and roughness were statistically analyzed with one‐way ANOVA followed by S‐N‐K post hoc comparisons ( a = 0.05). Results The surface roughness of the SLA group (0.38 ± 0.03 µm) and the DLP group (0.37 ± 0.04 µm) were both significantly higher than the CNC group (0.16 ± 0.00 µm) ( p < 0.001). AFM results revealed irregular surface of SLA and DLP zirconia. No significant difference was found in SBS value of the three groups ( p = 0.253). SEM image showed different failure modes including cohesive, adhesive, and mixed failure. Conclusion The bonding ability of SLA and DLP zirconia to veneering ceramic were comparable with that of CNC zirconia.