The effectiveness of in-office dental bleaching with and without sonic activation: A randomized, split-mouth, double-blind clinical trial.

Objective: This study was aimed at comparing the bleaching efficacy and bleaching sensitivity (BS) of two higher-concentration in-office bleaching gels (37% carbamide peroxide [CP] and 38% hydrogen peroxide [HP]) applied under two conditions: alone or in association with sonic activation.

Methods: Fifty-six volunteers were randomly assigned in the split-mouth design into the following groups: CP, CP with sonic activation (CPS), HP, and HP with sonic activation (HPS). Two in-office bleaching sessions were performed. Color was evaluated using Vita Classical, Vita Bleachedguide, and digital spectrophotometer at baseline and at 30 days post-bleaching. Absolute risk and intensity of BS were recorded using two pain scales. All data were evaluated statistically (color changes [t test], BS [Chi-square and McNemar test], and BS intensity [VAS; t test; NRS; Wilcoxon; α = 0.05]).

Results: Significant and higher whitening was observed for HP when compared with CP (p < 0.04). However, higher BS intensity was observed in the former (p < 0.001). No significant difference was observed in whitening effect or BS when the HP or CP bleaching gels were agitated (sonic application) compared with when they were not (p > 0.05).

Conclusion: The 37% CP gel demonstrated lower bleaching efficacy and lower BS compared with the 38% HP bleaching gel. The whitening effect was not influenced by the use of sonic activation.

Clinical Significance: The use of 37% CP gel did not achieve the same whitening effect when compared to 38% HP gel used for in-office bleaching. The use of sonic activation offers no benefit for in-office bleaching.