In‐Office Dental Bleaching Using 37% Carbamide Peroxide Versus 35% Hydrogen Peroxide: A Randomized, Double‐Blind Clinical Trial

Objective Compare the tooth sensitivity (TS) and bleaching efficacy (BE) of in‐office dental bleaching performed with 35% hydrogen peroxide (HP) or 37% carbamide peroxide (CP). Materials and Methods Sixty‐six participants were randomly divided into two groups according to the bleaching gel applied to the right hemiarch: 35% HP, or 37% CP. TS was recorded immediately after, up to 1, 24, and 48 h after bleaching, using the VAS and NRS scales. BE was assessed before bleaching and 1 month after using color guide units (ΔSGUs) and a spectrophotometer (Δ E ab , Δ E 00 , and ΔWI D ). TS was assessed using McNemar's and paired t ‐test (VAS) or Wilcoxon signed rank (NRS). The paired t ‐test was used to analyze BE ( α = 0.05). Results TS risk and intensity were lower for the 37% CP ( p = 0.003 and p < 0.005). Despite significant differences between the groups after 1 month (ΔSGU and Δ E 00 ; p < 0.05), the color measurements of both groups exceeded the 50%:50% perceptibility/acceptability threshold. Conclusion In‐office dental bleaching using 37% CP resulted in reduced risk and TS intensity, without prejudice to the BE. Clinical Relevance The use of 37% CP for in‐office dental bleaching could decrease TS risk and intensity without affecting BE. Trial Registration: ClinicalTrials.gov identifier: RBR‐683qhf