Pre-sintered Y-TZP sandblasting: Effect on surface roughness,phase transformation,and Y-TZP/veneer bond strength

Sandblasting is a common method to try to improve the y-tzp/veneer bond strength of dental prostheses,however,it may put stress on zirconia surfaces and could accelerate the t→m phase transformation. y-tzp sandblasting before sintering could be an alternative to improve surface roughness and bonding strength of veneering ceramic. objectives. the aim of this study was to analyze the effect of y-tzp pre-sintering sandblasting on surface roughness,phase transformation,and the y-tzp/veneer shear bond strength. material and methods. the y-tzp specimen surface underwent sandblasting with aluminum oxide (50 μm) pre-sintering (z-pre) and post-sintering (z-pos). z-ctr was not subjected to surface treatment. after ceramic veneer application,the specimens were subjected to shear bond testing. surface roughness was analyzed by confocal microscopy. y-tzp monoclinic and tetragonal phases were evaluated by micro-raman spectroscopy. shear bond strength and surface roughness data were analyzed by one-way anova and tukey tests (α=0.05). differences in the wave numbers and the broadening bands of the raman spectra were compared among groups. results. z-pos (9.73±5.36 mpa) and z-pre (7.94±2.52 mpa) showed the highest bond strength,significantly higher than that of z-ctr (5.54±2.14 mpa). the ra of z-pre (1.59±0.23 µm) was much greater and significantly different from that of z-ctr (0.29±0.05 µm) and z-pos (0.77±0.13 µm). all groups showed bands typical of the tetragonal (t) and monoclinic (m) phases. y-tzp sandblasting before sintering resulted in rougher surfaces but did not increase the shear bond strength compared to post-sintering and increased surface defects. conclusions. surface treatment with al3o2,regardless of the moment and application,improves the results of y-tzp/veneer bonding and is not a specific cause of t→m transformation. © 2017,faculdade de odontologia de bauru. all rights reserved.