Efeito do tempo de aplicação de peróxido de hidrogênio 4% na eficácia do clareamento caseiro e sensibilidade dental: estudo clínico randomizado paralelo cego

Abstract

ABSTRACT This study aimed to compare a short 30-min daily application time with the recommended 120-min time of 4% hydrogen peroxide for at-home bleaching on the risk/intensity of TS and color change. A single-blind, parallel, randomized clinical trial was conducted on 92 caries-free adult patients with canines A2 or darker which was randomly allocated to two groups (n=46) with different daily regimens. Customized bleaching trays containing 4% hydrogen peroxide were used for patients for three-weeks. A four-week regimen was offered for patients of the 30 min/day group. Color change was assessed with the Vita Classical and Vita Bleachedguide shade guides and with the Vita Easyshade spectrophotometer at baseline, weekly and 30 days after the end of the bleaching. The absolute risk and intensity of TS was assessed daily through the 0-10 VAS and 5-point NRS scale for 21 days, and patient satisfaction were recorded with a Likert 0-7 scale after the end of the treatment. Risk of TS (Fisher’s test), intensity of TS in NRS scale (Mann-Whitney test) and VAS scale (t-test independent) were compared. Color changes (ΔSGU and E76, E00) were evaluated by t-test independent. Color change between baseline and 3-weeks was statistically different when evaluated with shade guides unit (mean difference of around 1 shade guide unit in all time assessments; p < 0.05) but similar when the 30-min group received an extra week of bleaching (p > 0.05). There was no statistically significant difference between groups for the absolute risk of TS (p = 0,34), and not to the intensity of TS (p > 0,05). There was no difference (p > 0.05) in the patient’s satisfaction between groups. The application of 4% PH for 30 min/day is effective to whiten teeth, although bleached slightly less than 120-min protocol. High patient satisfaction was reported in both groups and similar level of TS was observed.