Stereolithography-manufactured zirconia substrate with bionic-patterned surface microstructure for enhancing bond strength to porcelain veneer

The bond strength between the zirconia substrates and porcelain materials has been extensively investigated, and sandblasting is one of the most effective methods for increasing the bond strength between zirconia and porcelain. However, it also introduces microcracks and pollution, which have a negative impact on the final mechanical properties of zirconia restorations. To increase the mechanical chimaerism of zirconia/veneer structures nondestructively, in this study we developed a novel surface design called a bionic-patterned surface microstructure (BSM) using stereolithography (SLA) technology. Inspired by the dentin–enamel junction model, the microstructure includes a cylinder and pit. Among all the specimens, both computer numerical control (CNC) zirconia with sandblasting and SLA zirconia with BSM showed higher bond strengths than the CNC group (P < 0.001), and the BSM groups showed improved bonding properties (P < 0.001). No significant differences were observed between the cylindrical and pit BSM at the same height/depth (P = 0.493), and for BSM of the same type, the bond strength increased with increasing height/depth (P < 0.001). Zirconia with BSM thus had superior bond strength to porcelain veneers. The height/depth of the BSM had a positive effect on the bonding strength, whereas the type had no effect.