Effect of potassium nitrate on tooth sensitivity during in-office bleaching: A randomized clinical trial.

Background: The study is a triple-blind, split-mouth, randomized trial to evaluate and to compare the effect of different concentrations of potassium nitrate (PN) prior to in-office bleaching on tooth sensitivity (TS).

Material and methods: Sixty participants were randomly divided into groups (n=30): Group A: 5% PN (positive control) and 10% PN; and Group B: 5% PN (positive control) and 35% PN. Each concentration of PN was applied to a hemi-arch for 10 min, and then a 35% bleaching agent was applied. The participants underwent two sessions of bleaching with a one-week interval. TS was recorded using a questionnaire and a visual analog scale.

Results: According to McNemar's test, there was a significant reduction in the prevalence of TS in group A (p=0.013) and group B (p=0.000) across the time assessments. Fisher's Exact Test showed no significant difference between the control and treatment sides (p>0.05). There was a significant reduction in TS intensity for both groups (p<0.05).

Conclusions: The 10% and 35% PN were effective in reducing the prevalence and intensity of TS, as well as 5% PN, and the treatments did not affect color change. Key words:Clinical trial, dentin sensitivity, tooth bleaching, hydrogen peroxide, potassium nitrate.