Efficacy of in-office bleaching using coupled bleaching gel after one week of manipulation

INTERVENTION: It will be a triple‐blind split‐mouth study where the evaluator, the patient and the operator will not know the assignment of the groups. 40 patients will be allocated through a simple randomization, according to the manipulation of the gel (immediately before or after a week of manipulation). One hemi‐arcade will receive the manipulated gel immediately before application and the other hemi‐arcade will receive the gel after one week of manipulation. Whitening will be performed with 40% hydrogen peroxide in two 40‐minute sessions. Then the whitening gel will be aspirated with a disposable sucker and the teeth will be cleaned with gauze and washed thoroughly with water. CONDITION: C07.793 Dentin Sensitivity; Gingiva; Tooth Discoloration PRIMARY OUTCOME: Evaluate the effectiveness of the color change. Data collected before, weekly for 2 weeks and 30 days after the end of treatment, using the subjective scales method, and; digital spectrophotometer. SECONDARY OUTCOME: Assess the absolute risk of gingival irritation. Patients will be expected to report irritation at some point or up to 48 hours after each session using the VAS visual analogue scale (0 to 10). The percentage of patients with pain will be called the absolute risk of gingival irritation. Assess the absolute risk of tooth sensitivity. Patients will be expected to report spontaneous pain at some point or up to 48 hours after each session, using the VAS visual analogue scale (0 to 10). The percentage of patients with pain will be called the absolute risk of tooth sensitivity. Evaluate Aesthetic Self‐Perception using the Orofacial Aesthetic Scale (OEE) before, weekly for 2 weeks and one month after the end of the procedure. Evaluate the intensity of dental sensitivity through the records made by the patients using the visual analogue VAS scale (0 to 10). Values ??will be presented as mean and standard deviation. Evaluate the intensity of gingival irritation through the records made by patients using the VAS visual analogue scale (0 to 10). Values ??will be presented as mean and standard deviation. INCLUSION CRITERIA: Age between 18 and 60 years; both genders; good general and oral health; healthy vital teeth; minimum color A2; agree and sign the informed consent form (TCLE)