Tooth sensitivity of in-office dental whitening in different arches: a randomized clinical trial

The thickness of teeth undergoing whitening can directly influence the amount of peroxide that reaches the pulp chamber, causing different levels of tooth sensitivity. The aim of this study is to compare the risk and intensity of tooth sensitivity and the effectiveness of whitening in the upper and lower arches after in-office teeth whitening. 90 participants were randomly divided into two groups according to the arch in which they received a 35% hydrogen peroxide gel first (1 x 30 minutes; 1 week apart). Tooth sensitivity was recorded immediately after, up to 1 h, 24 h and 48 h after whitening, using the VAS scale of 0-10. Whitening efficacy was evaluated before bleaching and 15 days after the end of treatment. Tooth sensitivity was compared using McNemar's exact test (a = 0.05), paired t-test, and One-way ANOVA. Whitening efficacy was compared using the paired t-test. The risk and intensity of tooth sensitivity was statistically higher for the lower arch (p = 0.0021 and p = 0.003, respectively). Both arches demonstrated significant whitening efficacy, with no differences between the arches (p > 0.05). In-office tooth whitening induced a greater risk of tooth sensitivity in the lower arch when compared to the upper arch, without significant differences in whitening effectiveness. .