Chromatic analysis of teeth exposed to different mouthrinses.

Objectives: The aim of this study was to assess, in vitro, the color of teeth exposed to different mouthrinses for a prolonged period.

Methods: Bovine teeth were distributed in four groups: control, alcohol-containing mouthrinse (Listerine(®)), alcohol-free mouthrinse (Oral-B(®)) and chlorhexidine mouthrinse (Periogard(®)). The teeth were submitted to two cycles of staining and artificial aging. Color evaluation was performed with a digital spectrophotometer at the beginning of the experiment and after every cycle. Color changes were characterised using the system defined by the Comission Internationale de L'Eclairage (CIE L*, a*, b*). Data were analysed using the ANOVA and Tukey's post hoc test.

Results: After the two cycles of staining and artificial aging, ΔE, ΔL and Δb from the alcohol-containing mouthrinse showed statistically significant differences when compared to the other groups. The ΔE values of the Listerine(®) group after the two cycles were greater than 3.7, indicating a visually perceptible color change.

Conclusions: The teeth exposed to the alcohol-containing mouthwash Listerine(®) were the only ones that presented a clinically perceptible color change.

Clinical Significance Statement: A blue-colored alcohol-containing mouthwash was shown to be capable of causing dental color change after a prolonged period of exposure. Special care must be taken when choosing and prescribing the prolonged use of the same mouthwash.