Effect of Glutaraldehyde-based Desensitizer in the Control of Tooth Sensitivity and Tooth Color Post- Whitening

Tooth whitening will be performed in 3 sessions with an interval of 7 days. Desensitizing agent and placebo will be applied in all sessions in a split mouth design . All groups will receive in-office bleaching treatment according to the steps described below:1 Prophylaxis; 2- Application of gingival barrier; 3- Application of the desensitizing product or placebo in accordance with the established groups; 4- Handling the bleaching material following the manufacturer's instructions: applications of whiteness HP35% bleaching gel for 15 minutes each, totaling 45 minutes; 5- Final removal of the whitening gel and the gingival barrier followed by washing with water. Application of the desensitizer or its placebo (step 3) will follow the following sequence:1. Relative insulation with cotton rolls; 2- Active application of the product on the buccal surfaces of all teeth with the aid of a Microbrush for 10 seconds.; 3- Wait 60 seconds and apply a light jet of air until the tooth surface is no longer shiny; 4- Wash with water for 10 seconds. To assess the patient's perception of pain, participants will be provided with a questionnaire to be filled out daily for 21 days from the first whitening treatment session. The criteria are based on the personal perception of the pain threshold, related to the level of sensitivity caused by bleaching treatment. The visual analogue scale (VAS) will be adopted as a reference. Numerical scale on which the number 0 (zero) corresponds to total absence of pain and 10 (ten) to maximum bearable pain. The color records of the bleached teeth will be performed by a single evaluator who will do it session :T0- baseline, T1- a week after the first session; T2- a week after the second session; T3- a week after the third session. An area of interest for color registration will be the middle third of the buccal surface of the teeth, following the the guidelines of the American Dental Association. Visual analysis will be performed using a Vita Classical scale following a color scale order organized by value. A second color analysis will be performed with the aid of a spectrophotometer that acts according to the CIELab and CIEDE 2000 system. The region for color evaluation with the Easyshade will be standardized as the middle third of the buccal surface of the anterior teeth.