Bond strength of heat-pressed veneer ceramics to zirconia with various blasting conditions

BACKGROUND/PURPOSE: With the technology of dental prostheses and materials progress, the bond durability of the all-ceramic restoration system plays an important role in the oral environment. The purpose of this study was to evaluate the influence of the parameters of blasting on the shear bond strength between zirconia and pressed veneer ceramics. MATERIALS AND METHODS: Zirconia was blasted with different alumina particle size subjected to two types of applied pressures. Heat-pressed and layered veneer ceramic blocks were served as an experimental group and control group, respectively. The shear strength of specimens after thermocycling for 20,000 times was also investigated to simulate oral environment. RESULTS: The results indicated that the surface roughness was increased significantly (P < 0.05) with increasing particle size of alumina and blasting pressure. The alumina particle size had statistically significant influence (P < 0.05) on shear strength of heat-pressed groups. Among heat-pressed ceramic specimens, the highest and lowest shear strength could be obtained when 50 μm of alumina was used at pressure of 0.3 MPa and 110 μm of alumina was used at 0.5 MPa, respectively. The negligible effect of thermal cycle on shear strength of heat-pressed groups can be seen. CONCLUSION: Blasting with 50 μm of alumina at 0.3 MPa could enhance the bond strength between zirconia and veneer ceramics.