Evaluation in the level of pain and color change in the Different Application Times of the In-office Bleaching

INTERVENTION: Co‐participatory randomized clinical trial in humans. Eighty‐four (84) research subjects ‐ 42 residents in the State of Rio de Janeiro and 42 in the State of Sergipe ‐ with a minimum age of 18 years old, will compose 3 randomly distributed sample groups. Each group will be composed of 28 patients who will be submitted to three whitening sessions of the same product, with a one week interval between them. Each group will follow an application time: Experimental Group ‐ single application of the bleaching gel for 20 minutes; Experimental Group 2 ‐ single application for 40 minutes; Control Group ‐ two applications of the bleaching gel for 20 minutes each, in the same appointment, one after the other. A randomization list will be created by an operator that will not participate in the evaluations, through the website www.sealedenvelope.com to define the whitening protocol to be performed. This way he will use an initiator (seed) in 1, 2 and 3 groups, for an extension list of 84 patients. Then, he will produce sealed envelopes numbered from 1 to 84, containing inside the tooth whitening protocol to be used by the participants. They will be sorted from 1 to 84 in increasing order of evaluation and screening. This study was blinded because the evaluators, who will collect information on satisfaction and sensitivity, and the operators, who will perform the procedure, are different people. CONDITION: Dentin Sensitivity. Esthetics. E06.420.750 PRIMARY OUTCOME: The application of the bleaching gel for a reduced time (single application of 20 min), will promote less sensitivity than the control group (2 applications of 20 min each), but also less bleaching potential. The data will be evaluated using statistical analysis SECONDARY OUTCOME: The application of the bleaching gel for 40 minutes directly, and without exchange, will promote color alteration and sensitivity level similar to the control group (2 applications of 20 minutes each). The data will be evaluated through statistical analysis INCLUSION CRITERIA: Any individual presenting interest in tooth bleaching who is at least 18 years old; Patients who have maxillary anterior canines with a color equal to or darker than 2.5 M2 (on the Vita Bleachguide scale); Agree to participate and sign the informed consent form.