Considering the lack of studies related to the violet LED light (405-410nm), applied to tooth whitening, as well as the lack of protocols for its use, this study aims to evaluate if bleaching gel renewal during dental office whitening associated with Violet LED light interferes with final color result and postoperative sensitivity in a randomized, blinded, split-mouth study. Thirty-three volunteers will be selected to participate in the study (n = 33), and the study groups will be: G1 (Permanence of the Whitening Gel on the tooth enamel for 15 minutes) and G2 (3 Whitening Gel renewal every 5 minutes - Total of 15 minutes). In both G1 and G2, teeth will be illuminated with the Violet LED (405-410nm). In the same patient the two treatments (G1 and G2) will be performed, with a split-mouth protocol. The primary outcome will be immediate and mediated color change, quantitatively assessed by colorimetric (color scale) and spectrophotometry tests. Dental sensitivity will also be evaluated during and after tooth whitening using the VAS pain scale. There will be 3 whitening sessions with a 7-day interval between them. The alteration of color and presence of sensitivity will also be evaluated at the times of 14 days and 2 months after the whitening ends. A gel containing 35% hydrogen peroxide will be used. The final color evaluator and responsible for interviewing the patient about the sensitivity will be blind as to which treatment was applied on each side of the patient's arcade.

Inclusion Criteria:

• Good oral hygiene conditions
• Good general health conditions and without systemic disease
• Presence of all teeth, without caries, periodontal disease, restorations, endodontic treatment, crowns
• Patients with dental color A3 or darker, according to the VITA * Classical Color Scale.

Exclusion Criteria:

• Pregnant and lactating female patients
• Presence of caries, periodontal disease or any other infectious source in the oral cavity
• Systematic use of tobacco and alcoholic beverages
• Chronic use of corticosteroids, as well as who makes use of analgesics or anti-inflammatories before or during 48 hours after dental bleaching
• Patients with dentin hypersensitivity
• Patients with tooth color alteration by tetracycline, fluorosis, endodontic treatment.
• Volunteers who use removable prostheses