How could mouthwashes affect the color stability and translucency of various types of monolithic zirconia? An in-vitro study

ObjectivesThis study aimed to evaluate the color stability and translucency of various types of monolithic zirconia after immersion in chlorhexidine and Listerine mouthwashes.Materials and methodsThis experimental study was performed on 36 disk-shaped specimens fabricated from low-translucent, high-translucent, and multilayered monolithic zirconia (n = 12 per group). Each group was equally divided and immersed in either 2% chlorhexidine (CHX) or Listerine mouthwash for 2 min daily over 7 days. Changes in color (Delta E) and the translucency parameter (Delta TP) were evaluated and compared. The data were analyzed with one-way ANOVA followed by Tukey's post-hoc tests (alpha = 0.05).ResultsChlorhexidine caused a significantly lower Delta E and a significantly higher Delta TP in multilayered zirconia compared to the low-translucency (Delta E: P = 0.0027, Delta TP: P<0.001) and the high-translucency zirconia group (Delta E: P<0.001, Delta TP: P = 0.022). Listerine caused a significantly higher Delta E in the high-translucency zirconia group compared to the multilayered zirconia group (P = 0.0165). It also resulted in a significantly higher mean Delta TP in the multilayered zirconia group compared to the low-translucency (P = 0.0003) and high-translucency zirconia groups (P = 0.019).ConclusionsIn both mouthwashes, multilayered monolithic zirconia exhibited the highest color stability among the tested materials; albeit with the most pronounced changes in translucency. Meanwhile, high-translucency monolithic zirconia was more prone to discoloration when exposed to both mouthwashes.