Sonic Activation of a Desensitizing Gel Prior to In-Office Bleaching

This double-blind, randomized, and controlled clinical trial evaluated the effect of sonic activation during the application of a desensitizing agent (DA) containing 5% potassium nitrate and 2% sodium fluoride on the occurrence of tooth sensitivity (TS) associated with in-office dental bleaching. Treatment with or without sonic activation of the DA was randomly assigned to one-half of the maxillary teeth of 34 patients in a split-mouth design. On the side without sonic activation (noSA), the DA was applied and maintained in contact with the teeth for 10 minutes. On the sonic activation side (SA), the DA was activated 30 seconds per tooth. The DA application was followed by application of 35% hydrogen peroxide in two bleaching sessions separated by a one-week interval. The primary outcome was the absolute risk of TS, recorded using a numeric rating scale and a visual analog scale. Color was evaluated with a digital spectrophotometer and a value-oriented shade guide. No significant difference between treatments was observed in the absolute risk of TS, which occurred in 93% (p=1.00) of both noSA and SA groups. The TS intensity was higher in the 24-hour interval after sessions, for both treatments, without differences between them. There was no difference in the color change for the treatments, with the average change in number of shade guide units of the Vita Classical scale of 6.35 for both (p=0.87). Sonic activation of DA containing 5% potassium nitrate and 2% sodium fluoride did not reduce the absolute risk and intensity of TS associated with in-office bleaching.