Effect of Grit-blasting on the Color Stability of Zirconia Ceramics Following Exposure to Beverages

Aim The aim of this study was to evaluate the effect of grit-blasting on the color stability of zirconia ceramics following exposure to beverages. Method A total of 80 planar zirconia specimens were prepared from dense sintered zirconium blocks and were randomly allocated into four groups (n=20). Ten specimens from each group were grit-blasted (GB) using aluminum trioxide powder from a distance of 10 mm. The remaining 10 specimens were used as such without grit-blasting (NGB). The grit-blasted and non-grit-blasted specimens were immersed in artificial saliva, Coffee, Red Bull, and Coca-Cola at room temperature over a 28-day test period. Color measurement (DeltaE) of the zirconia specimens was performed at baseline (T0) and after seven (T1), 14 (T2), and 28 (T3) days of immersion in the beverages using the Color Eye 7000A Spectrophotometer (Gretag Macbeth, New Windsor, NY). The data were analyzed using analysis of variance (ANOVA) and the post-hoc Bonferroni test. A p-value of less than 0.05 was considered statistically significant. Result The GB specimens immersed in coffee showed the highest color changes as compared to other groups (4.47+/- 0.04) and the NGB specimens stored in saliva showed the lowest DeltaE values (0.83+/- 0.03). Energy drinks and soft drinks showed similar DeltaE values at the end of the 28-day study period in both the NGB and GB groups. All the specimens, irrespective of the beverages, in both groups showed increased DeltaE values at different immersion periods except for NGB specimens immersed in saliva, which showed decreased DeltaE values from T2 to T3. Conclusion GB specimens showed increased DeltaEs compared to NGB Zirconia ceramics. Among the beverages, the coffee immersion of GB specimens showed marked color changes. The specimens immersed in the energy and acidic drinks from both groups showed perceivable color changes at the end of the 28-day study period.