Is the at-home bleaching treatment applied only on the lingual surface as effective as that on the buccal surface? A randomized clinical trial.

OBJECTIVES: This double-blind randomized clinical trial compared the effectiveness and bleaching sensitivity (BS) of at-home dental bleaching performed on the buccal surface and on the lingual surface. METHODS: Using a split-mouth design, 25 patients were assigned to two bleaching groups: 10% hydrogen peroxide (White Class 10%, FGM) applied once daily for 60 min to the buccal surface (BSB) and 10% hydrogen peroxide (White Class 10%, FGM) applied once daily for 60 min to the lingual surface (LSB), both for 14 days. The color was evaluated before bleaching, after the first and second weeks, and 1 month after the bleaching using Vita Classical and Vita Bleachedguide scales and a Vita Easyshade spectrophotometer. BS was recorded daily using a 0-4 numerical rating scale and a 0-10 visual analogue scale. The following statistical tests were used: color changes (Mann-Whitney), absolute risk of BS (McNemar's exact), and the intensity of BS (Mann-Whitney). In all statistical tests, the significance level was 5%. RESULTS: Significant bleaching was observed after the end of bleaching in both groups, with higher bleaching effectiveness for BSB when compared to LSB (p < 0.05). Regarding BS, no significant difference was observed between groups (p = 1.00). CONCLUSIONS: The 10% hydrogen peroxide (White Class 10%, FGM) applied in at-home bleaching performed on the lingual surface did not promote a similar result of color change compared to on the buccal surface. Regarding BS, there was no significant difference between the groups. CLINICAL RELEVANCE: The at-home bleaching performed on the lingual surface promotes a lower result in the color change. BS is similar between the groups. CLINICAL TRIAL REGISTRATION NUMBER: RBR-283byt.