The Effect of Different Solutions on Optical Behavior of Polished and Glazed Zirconia-Reinforced Lithium Silicate Ceramics

This study sought to assess the effect of glazing and polishing surface treatments on the optical behavior of zirconia-reinforced lithium silicate ceramics thermocycled in different solutions. Computer-aided design/computer-aided manufacturing ceramics (VITA Suprinity) were cut into samples (n=104) measuring 1.5x14x10 mm according to the manufacturer’s instructions. Also, the samples were then randomly divided into four groups for immersion in artificial saliva, tea, orange juice and cola. A spectrophotometer was used to assess the color change and changes in L* coordinate against a white and a black background. The translucency parameter and contrast ratio were also calculated. The ∆E and L* values were analyzed using two-way ANOVA test. Student’s t-test was applied to analyze TP and CR. The interaction effect of the type of solution and type of surface treatment on color change against a white (P=0.008) and black (P<0.001) background was statistically significant. Immersion of ceramic samples in orange juice and cola caused significant changes in TP and CR in the polishing and glazing groups (P < 0.05). Immersion in orange juice causes clinically perceivable color change in glazed ZLS ceramics. Immersion in cola decreases the translucency of both polished and glazed ZLS ceramics.