Effect of a toothpaste for sensitive teeth and repair of enamel on the sensitivity and effectiveness of in-office dental bleaching

This study aimed to evaluate the desensitizing effect of a toothpaste for sensitive teeth on the sensitivity and whitening efficacy of the 38% hydrogen peroxide bleaching agent used for in-office whitening compared with a regular toothpaste in a randomized clinical trial. Fifty subjects, with a maxillary right central incisor (11) with a color value lower than A1, were selected for this double-blind randomized clinical trial. Patients were randomly allocated to two experimental groups: control group, which used a regular toothpaste; and the test group, which used a toothpaste for sensitivity. The intervention consisted of the application of toothpaste, with the aid of an individual tray, for a period of 4 min daily, starting one week before the first whitening session and stopping use immediately after the second session. After allocation to one of the groups, subjects received in-office tooth whitening with a single 40-min application of 38% hydrogen peroxide, in two sessions, one week apart. The incidence and intensity of sensitivity were evaluated by a visual analogue scale and a numerical analogue scale. Sensitivity was measured immediately before each session, 1h, 24h and 48h after each whitening session, and four weeks after the second whitening session. Tooth color was assessed using a spectrophotometer and by comparison with Vitapan Classical and Vita Bleachedguide 3D Master shade scales. Teeth color was evaluated before the first whitening session, one week after the first session, one week after the second session and four weeks after the second whitening session. Participants and professionals who performed the bleaching and color and sensitivity assessments were blinded to the experimental group of patients. For the incidence of hypersensitivity, the results were evaluated by comparing the experimental groups at different times of evaluation with the Mann-Whitney test for comparison between groups and the Friedman test for repeated measures and the Tukey test for comparison of times. The color change in the color scales was analyzed using the Mann-Whitney test for comparison between groups and the Wilcoxon test for comparison between times. The color change by the spectrophotometer was analyzed by the t test for comparison between groups and the paired t test for comparison between times. All analyzes were performed considering a significance level of 5%. There was no difference in the pattern of dental hypersensitivity between the groups. For all color measurements, there was no difference between the whitening result, no statistically significant difference was observed between the study groups.