Efficacy of Tooth Bleaching with 35% and 6% Hydrogen Peroxide in Primary Dentition: Study Protocol for a Randomized Controlled Clinical Trial

Background: The aesthetics of dental elements generates significant psychological and social impacts, both in primary and permanent dentition. One of the most employed techniques to visually improve the appearance of teeth is bleaching. In in-office whitening, the technique used consists of applying whitening gel to dental surfaces in concentrations ranging from 25% to 50% of hydrogen peroxide. However, recent studies showed that low and medium concentration bleaching agents based on hydrogen peroxide have been effective and present a lower risk of sensitivity to the patient. Aims: To carry out a controlled and randomized clinical trial to compare the effectiveness of dental bleaching in primary teeth with hydrogen peroxide at concentrations of 35% and 6%. Methods: In this study, 38 patients aged 3 to 6 years-old will be selected and allocated in 2 groups (G1 - Hydrogen Peroxide 35%, n=19 and G2- Hydrogen Peroxide 6%, n=19). Bleaching will be carried out in up to three sessions, with an interval of 7 days between each session. Evaluation of color and tooth sensitivity will be carried out 48 hours after each bleaching session. The color assessment will be measured with the aid of a digital spectrometer while the tooth sensitivity will be assessed by using the Pain Level Scale (Wong-Baker Faces®). Discussion: It is expected that there will be no significant difference between the groups in terms of color variation and that the low concentration bleaching group will have the lowest sensitivity index.