The effect of various polishing systems on surface roughness and phase transformation of monolithic zirconia

Abstract

The purpose of this study was to evaluate and compare three polishing systems on the surfaceroughness and phase transformation of monolithic zirconia. MATERIALS AND METHODS. 100 disk shapedspecimens (10 mm diameter, 3 mm thickness) were fabricated from monolithic zirconia blocks. 20 specimenswere left as a control group and remaining specimens were grinded by diamond bur to simulate the occlusaladjustments. Grinded specimens were randomly divided into 4 groups: group G (no polishing), group M(Meisinger, zirconia polishing kit), group E (EVE Diacera, zirconia polishing kit), and group P (EVE Diapol,porcelain polishing kit). Surface roughness was measured with profilometer and surface topography wasobserved with SEM. XRD analysis was performed to investigate the phase transformation. Statistical analysis wasperformed with one-way ANOVA and Tukey's post hoc tests at a significance level of P=.05. RESULTS. Allpolishing groups showed a smoother surface than group G. Among 3 polishing systems, group M and group Eexhibited a smoother surface than the group P. However, no significant differences were observed between groupM and group E (P>.05). Grinding and polishing did not cause phase transformations in zirconia specimens.CONCLUSION. Zirconia polishing systems created a smoother surface on zirconia than the porcelain polishing.