Abstract
Objectives: To assess the effect of artificial gastric acid with and without brushing on color stability, surface gloss and surface hardness of colored zirconia. Materials and methods: Monochromatic zirconia (A) and zirconia colored before sintering (B) were milled into discs and sintered. Each material was divided into three groups (n=11/group): control (1), acid exposure (2), acid exposure and brushing (3). All groups, the control one excluded, were emerged into artificial gastric acid, rinsed with water, and stored in distilled water. Groups A3 and B3 were subjected to brushing. Changes in color, gloss and hardness were measured. Results and discussion: There was a significant difference in color after acid exposure with or without brushing in both materials (p<0.05). Surface hardness was significantly lower when exposed to acid with or without brushing, compared to the control group (p=0.0001). Surface gloss shows no statistical difference comparatively with the control groups (p>0.05). When comparing monochromatic and colored zirconia, no significant difference was found in any parameter. Conclusions: zirconia exposure to gastric acid with or without brushing will affect its color and lower its surface hardness, regardless the application of coloring stains.