[Clinical evaluation of the effect of reducing tooth sensitivity caused by in office bleaching using dentifrices].

OBJECTIVE: To evaluate tooth sensitivity and the efficacy of in-office bleaching when using different desensitizing dentifrices. METHODS: In total, 150 eligible individuals were recruited and randomized by computer-generated block randomization into three groups: potassium nitrate group (n=50), stannous fluoride group (n=50), and placebo group (n=50). Participants were asked to use a desensitizing dentifrice and toothbrush 15 days prior to and after the in-office bleaching. Each patient received a one-session in-office bleaching with 35% hydrogen peroxide whitening gel. The in-office bleaching included three 15 min operations, totally 45 min. Tooth sensitivity was evaluated by 100 mm visual analog scale (VAS) scores immediately 0 d and 1 d, 2 d, 7 d, 14 d, and 30 d after in-office bleaching. In total, 48 (96%), 45 (90%), and 46 (92%) individuals in the potassium nitrate, stannous fluoride, and placebo groups, respectively, completed the follow-up observations. RESULTS: Data were analyzed using analysis of covariance (ANOVA). For tooth sensitivity produced by in-office bleaching, the mean VAS values of the three groups were analyzed. At 0 d immediately after surgery, the mean VAS of the potassium nitrate group was 39.22+/-15.08, which was lower than that of the stannous fluoride group (47.18+/-12.59) and the placebo group (52.53+/-14.05), and the difference was statistically significant (P<0.05). The results of the stannous fluoride group and the placebo group were similar, and the difference was not statistically significant (P>0.05). On 1 day postoperatively, the mean VAS of the potassium nitrate group was 38.27+/-16.52, which was lower than that of the stannous fluoride group (44.69+/-14.92) and the placebo group (44.45+/-13.54), P<0.05. The results of the stannous fluoride group and the placebo group were similar, and the difference was not statistically significant (P>0.05). The mean values of VAS were similar 2 d, 7 d, 14 d and 30 d after operation, and the difference was not statistically significant (P>0.05). CONCLUSION: Compared with the stannous fluoride group and the placebo group, the use of potassium nitrate desensitizing toothpaste 15 days before surgery can effectively alleviate the tooth sensitivity during and after in-office bleaching.