Preventive effect of a desensitizing gel before in-office tooth bleaching

Objectives: The aim of this double-blind randomized clinical study was to evaluate whether the use of a desensitizing agent (5% potassium nitrate and 2% sodium fluoride [Desensibilize KF 2%, FGM]) before in-office bleaching would decrease tooth sensitivity when compared to a placebo. Methods: 30 caries-free patients, over 18 years were divided into control and experimental groups. Before in-office bleaching with 35% peroxide hydrogen gel (Whiteness HP, FGM) in three applications of 15-min each, a placebo gel was applied in the buccal surfaces of all teeth from the control group for 10 min. A similar procedure was performed in the experimental group, however instead of a placebo gel, a desensitizing agent was employed for the same time. The same bleaching protocol was repeated in another clinical appointment after 1 week. The patients recorded their perception of tooth sensitivity on a 0-4 scale. The means and standard deviations for changes (Δ sgu) at each week recall for both groups as well as the tooth sensitivity intensity were compared using Student's t-test (α=0.05). The percentage of patients with tooth sensitivity and the intensity of sensitivity were analyzed using the Fisher's exact test and the Student's t-test (α=0.05), respectively. Results: The use of desensitizing gel did not affect the bleaching efficacy of the hydrogen peroxide agent (p>0.05). 46.6% of patients from the experimental group had tooth sensitivity while this figure was significantly higher for patients from the control group (86.6%) (p=0.04).The tooth intensity was also higher for the control (median:2) compared to the experimental group (median:0) (p=0.008). Conclusions: It was concluded that the use of the desensitizing gel based on 5% nitrate potassium and 2% sodium fluoride before the in-office bleaching regimen does not affect the bleaching efficacy and reduce the tooth sensitivity experience.