Effect of sandblasting on the mechanical properties of Y-TZP zirconia.

Surface modification techniques affect phase transformation which in turn influences strength of zirconia biomaterial. The study aimed at evaluating the tetragonal to monoclinic (t-m) phase transition of zirconia occurring after sandblasting three different ceramic abrasive materials and its subsequent effect on the strength. Zirconia bars (n=24) were sandblasted using silicon carbide (SiC), alumina (Al2O3) and zirconia (ZrO2) particles. After surface characterization by a scanning electron microscope (SEM) and a laser profilometer, the relative amount of transformed monoclinic (m) phase was analyzed by X-ray diffractometry (XRD) and its corresponding effect on the flexural strength and fatigue strength were determined. Data were analyzed using one-way analysis of variance ANOVA (p<0.05). Furthermore, Weibull statistics was used to analyze the variability of flexural strength. The highest amount of monoclinic content was found after sandblasting with SiC consequently resulting in an increased flexural strength and fracture resistance under cyclic load conditions. Weibull modulus was reduced in all the groups with SiC blasting showing the least degradation of m values. The strengthening mechanism that is attributed to sandblasting procedure is influenced by the abrasive material used.