The sample size calculation was carried out based on a previous study. To detect the bleaching effect with a power of 80% and a one-tailed alpha error of 5%, a sample size of 20 subjects in each treatment group was necessary to detect a 20% difference between groups in shade change. A 20% addiction in subjects' number, taking into consideration potential loss or refusal, gave a total sample size of 75 subjects (25 in each group). The individuals were invited to participate in this clinical trial through advertisement exposed at the Federal University of Paraíba, Brazil.