Efficacy of In-Office Bleaching Using 35% Hydrogen Peroxide in an Attachable Syringe Varying the Application Tip: A Double-Blind Randomized Clinical Trial

Objective: This randomized clinical trial evaluated the bleaching efficacy (BE), absolute risk and intensity of tooth sensitivity (TS), gingival irritation (GI), and esthetic self-perception (ES) of an in-office bleaching gel with an attachable syringe using different application tips in a randomized, double-blind (participant- and evaluator-blinded) clinical trial. Materials and Methods: Forty-five participants received hemi-arch bleaching using an attached brush and a conventional tip, performed in two sessions with hydrogen peroxide 35%. BE was evaluated at baseline, weekly, and 1-month post-bleaching using a spectrophotometer (ΔEab, ΔE00, and ΔWID) and shade guide units (ΔSGU). The absolute risk and intensity of TS and GI using a VAS. ES was assessed using the Orofacial Esthetic Scale. BE was analyzed using repeated-measures ANOVA. TS and GI were evaluated using the McNemar test (absolute risk) or paired t-test (intensity and ES scores; α = 0.05). Results: BE was observed for both groups, with no statistical difference (p > 0.05) across all parameters. The absolute and intensity of TS were comparable between brush and conventional tip (p > 0.05). ES was improved after bleaching (p < 0.05). Conclusion: The application tips showed equivalent bleaching efficacy and esthetic self-perception, as well as similar tooth sensitivity and gingival irritation. Clinical Significance: The brush applicator tip preserved bleaching efficacy while minimizing the volume of gel applied to the tooth surface, making it a more sustainable alternative.