Methods: Forty test specimens (12x14x2 mm) were fabricated from three ceramic systems, IPS e.max CAD, Cercon and Vitablocs Mark II all-ceramic. Specimens were divided into 4 groups (n=10) to receive 1 of the following 4 surface finishing techniques: 1) grinding burs, 2) polishing, 3) diamond paste and 4) glazing. After surface treatment the surface roughness (Ra) was measured using a profilometer and CIE L*a*b* values of the specimens were determined at baseline. All specimens were subjected to 300 h of accelerated aging and then 4% acetic acid at 80°C for 168 hours. Surface roughness and color measurements were repeated, and the total color differences (ΔE) were calculated. The data were analyzed with a 2-way ANOVA followed by Tukey HSD tests (P=0.05).
Results: Statistical analysis showed that surface roughness values varied significantly depending on the ceramic materials and surface finishing methods (P<0.05). There were significant differences among the ΔE values of ceramic materials after accelerated aging and acid treatment (P<0.05). The highest ΔE values were recorded for Vitablocs Mark II polishing group (1.77±0.28) and the lowest ΔE values were recorded for Cercon glazing group (0.66±0.15) in all-ceramic systems.
Conclusions: Within the limitations of this study, significant differences were found between the Ra values and significant changes in the L*, a*, and b* coordinates for all-ceramic materials tested. Accelerated aging and acid treatment didn’t change the color of all ceramic materials at levels considered clinically perceptible (ΔE<2.0).