Efficacy of 35 % self-mixed hydrogen peroxide In-office bleaching with reduced application time: A single-blind...

To evaluate the equivalence in bleaching efficacy (BE), tooth sensitivity (TS), gingival irritation (GI) and self-perception (AS) and the impact on oral condition (IO) among participants subjected to reduced application protocols for in-office dental bleaching.

In this split-mouth, single-blind, randomized clinical trial, 45 volunteers were randomly assigned based on the right hemi-arch. The same bleaching gel (Whiteness HP Automixx Plus 35 %, FGM) was applied using two protocols: 1) one 25-minute application (1 × 25 min) and 2) one 50-minute application (1 × 50 min). BE was evaluated using the Vita Easyshade spectrophotometer (ΔE_ab, ΔE₀₀, and ΔWI_D), as well as the Vita Classical, and Vita Bleachedguide shade guides (ΔSGU). TS and GI intensity were recorded using a 0-10 Visual Analogue Scale (VAS), while AS and IO were assessed pre- and post-procedure using the Orofacial Aesthetic Scale and the Oral Health Impact Profile-14, respectively. Statistical analyses included ANOVA for BE, McNemar's test for TS and GI risk, and paired t-tests for TS and GI intensity, as well AS and IO (α = 0.05).

Both protocols achieved equivalent BE (p > 0.05) accross all evaluated parameter. Both time protocols showed similar risk and intensity of TS and GI (p > 0.05). Significant AS and IO improvements were observed regardless of protocol (p < 0.05).

The 1 × 25-minute protocol demonstrated equivalent BE, risk and intensity of TS and GI compared to the 1 × 50-minute protocol, with shorter application time. Moreover, tooth bleaching enhanced the participants' AS and IO.

A simplified regimen involving a single 25-minute application offers effective bleaching since the first session and improves patient satisfaction, minimizing chair time for both patients and clinicians.