Efeito do pH na sensibilidade do clareamento de consultório em adultos: ensaio clínico randomizado duplo-cego

Abstract

Objectives: This randomized clinical trial aimed to evaluate the influence of pH on the tooth sensitivity (TS) of in-office tooth whitening in adult patients, using two types of whitening gels. Methods: Thirty-three patients were selected for this split-mouth clinical trial. In one group, the bleaching gel with an acidic pH was applied to the entire buccal tooth surface, and in the other group, the bleaching gel with an alkaline pH was applied in the same way. The teeth were whitened in two sessions with a one-week interval between them. The 35% hydrogen peroxide whitening gel (Whiteness HP 35%) was used in three 15-minute applications, resulting in 45 minutes. The other whitening gel (Whiteness HP blue 35%) was applied once for 45 minutes. Three measurements were taken with a pH meter on the buccal surface, one at the first moment of the application and two others every 15 minutes. TS was assessed at 1 hour, up to 24 hours, between 24 and 48 hours and 30 days after bleaching using the Numeric Rating Scale (NRS) and the Visual Analog Scale (VAS). The color change and the TS intensity were assessed by statistical analysis using the paired Wilcoxon test. The absolute risk of tooth sensitivity will be compared by the Mc Nemar test (α = 0.05). Results: The HP35 group showed a higher risk of TS (81,82%, 95% confidence interval [CI]) compared to the HPBlue SD group (60,61%, 95% confidence interval [CI]), as well as greater sensitivity intensity (HP35 1.21±1.70 and HPBlue 0,62±1.53; p=0.0013). There was no significant difference in bleaching efficacy between the groups, nor was there any difference in pH variation over the application time. Conclusion: Whitening gel with an alkaline pH showed better results in terms of TS. The pH values differed significantly between the groups, but there was no difference in pH stability over the course of the gels' applications. Whitening efficacy was observed in both groups with no significant changes regardless of the pH of the gel used.