This randomized, parallel, single-blind, placebo-controlled clinical trial aims to investigate the effects of an experimental 0.5% Libidibia ferrea gel on the control of post-bleaching tooth sensitivity and its influence on bleaching efficacy. Seventy-five selected volunteers will be randomly allocated into three groups: CT (placebo gel), KF2 (5% potassium nitrate and 2% sodium fluoride), and JUC (experimental Libidibia ferrea gel). Each group will receive the corresponding desensitizing treatment, and the assigned product will be actively applied to the labial surfaces of the anterior teeth and the buccal surfaces of the first premolars for 10 minutes. Subsequently, all groups will undergo an in-office tooth bleaching protocol with 35% hydrogen peroxide, consisting of two sessions with three 15-minute applications each, with a 7-day interval between sessions. Postoperative sensitivity will be recorded daily by the patients for 14 days using a visual analog scale (VAS), while tooth color will be measured using a spectrophotometer at baseline and one week after the end of treatment. Data will be subjected to statistical analysis according to sample distribution, with a statistical power of 80% and a significance level of 5%.

All groups will undergo in-office tooth bleaching treatment, performed in two sessions with a 7-day interval, according to the steps described below: prophylaxis; application of the desensitizing agent or placebo, according to the assigned group, for 10 minutes; rinsing with water; application of the gingival barrier; application of Whiteness HP 35% bleaching gel for 45 minutes, consisting of three 15-minute applications; final removal of the bleaching gel and gingival barrier, followed by rinsing with water. A lip retractor will be used during the application of the desensitizing agent or placebo and throughout the bleaching procedure. The assigned product will be actively applied using a microbrush.

Inclusion Criteria:

Good oral hygiene; Absence of active caries lesions; No previous tooth bleaching treatment; Absence of dental hypersensitivity; Not being pregnant; Presence of at least 28 teeth in the oral cavity.

Exclusion Criteria:

Volunteers undergoing orthodontic treatment; Presence of periodontal disease; Dental cracks or fractures; Restorations or prostheses on anterior teeth; Extensive restorations in molars; Gastroesophageal disorders; Severe intrinsic tooth discoloration; Presence of dentin exposure in anterior and/or posterior teeth.