Effect of Simulated Gastric Acid on Optical Properties of Different Monolithic Ceramics

Abstract

Objective: The purpose of this study was to evaluate the effect of simulated gastric acid on the color and translucency of monolithic ceramics. Materials and Methods: A total of forty ceramic disks made from four ceramic materials (10 each) were cut with a final thickness of 1.0 mm using Isomet saw from ceramic blocks of each material (Ceramil Zolid fx white [Z], IPS e.max CAD [E] HT A3, Vita Suprinity [S] HT A3, and Cerasmart [C] HT A3). Zirconia disks were then colored using A3 coloring liquid and sintered, while IPS e.max CAD and Vita Suprinity were crystallized according to their manufacturers' instructions. A spectrophotometer was used to evaluate color change (∆E) and translucency parameter (TP). L*a*b* color coordinates were determined over white and black backgrounds according to the CIE Lab 1976 color scale before and after immersion in simulated gastric acid (HCl) for 96 h at 37°C incubator. Collected data were statistically analyzed using ANOVA followed by Tukey's posthoc test and the significance level was set at P≤0.05. Results: The highest color change was recorded for group C followed by group E, group S, and the least change was with group Z. Translucency increased significantly (P˂0.05) after acid immersion for all materials except for group C. Conclusion: Zolid fx showed the greatest color stability after gastric acid immersion, while Cerasmart is the least one, however, all tested ceramics are within the clinically acceptable limit. Translucency increased after gastric acid immersion for all tested ceramics except for Cerasmart, it decreased.