Aim: To assess the effect of accelerated aging on the surface roughness and color stability of ultra-translucent and high-translucent zirconia.
Materials and methods: A total of sixteen discs (11mm diameter and 0.6mm thickness) were sliced from two materials; ultra (UTML) and high (HTML) translucent multilayered zirconia; Group UT and HT respectively. All samples were polished and subjected to accelerated aging using autoclave for 5-hours to simulate 15-years clinical service. Surface roughness was assessed using digital microscope and SEM. Color stability was assessed using laboratory spectrophotometer. After testing for normality, collected data revealed parametric distribution and were expressed as mean and SD. Data were statistically analyzed using Paired t-test and independent t-test at a level of significance (P0.05).
Results: Before aging, the mean surface roughness was (0.2508μm ±0.00152) and (0.25017μm ±0.00155) for Groups UT and HT respectively. After aging the mean surface roughness was (0.2533m ±0.0019) and (0.2536m ±0.0022) for Groups UT and HT respectively and E were (3.05 ± 0.31) and (3.71 ± 0.42) respectively. Paired-t test revealed that surface roughness increased significantly. After aging, however independent t-test revealed that there was in-significant difference between both groups regarding surface roughness, while significant difference regarding color stability was found.
Conclusion: It was concluded that accelerated aging significantly affects the surface roughness and color stability of ultra and high translucent zirconia.