Violet LED associated with high concentration hydrogen peroxide: Effects on bleaching efficacy, pH, and temperature.

Photodiagnosis Photodyn Ther

Department of Restorative Dentistry, School of Dentistry, Araraquara, São Paulo State University - UNESP, 1680 Humaitá Street - 3rd floor, Centro, Mail Box: 331, ZIP Code 14801-903, Araraquara, São Paulo, Brazil. Electronic address:

Published: December 2022

Background: This study aimed to evaluate the bleaching efficacy, pH, and temperature of 35% hydrogen peroxide (HP) gel used alone or associated with violet LED.

Methods: Sixty bovine crowns were sectioned (5 × 5 × 2mm). After staining with black tea, the specimens were randomized into four groups (n = 10) according to the bleaching protocol: HP35R: 3 × 15 min 35% HP; HP35: 1 × 45 min 35% HP; HP35VR: 3 × 8min 35% HP + Violet LED; HP35V: 1 × 24 min + Violet LED. Two bleaching sessions were performed for all the groups. Color change was evaluated before, 24h after each session, 7 days and 15 days after the last session. The variables ∆E [CIEDE2000] and W were used for color analysis. The pH variation (initial and final) and the temperature of the gel were recorded (n = 5). ANOVA two-way for repeated measures and Bonferroni post-test was used at a significance level of 5%.

Results: HP35VR and HP35V the most noticeable color change(p < 0.05). The final values of pH were lower than the initial ones, but with no difference between the groups (p > 0.05). Groups HP35VR and HP35V showed an increase in temperature in relation to HP35R (p < 0.05).

Conclusions: Violet LED improved the bleaching efficacy of 35% HP in a time-saving manner without negatively affecting the pH and temperature of 35% HP. The renewal of HP did not influence the outcomes.

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Source
http://dx.doi.org/10.1016/j.pdpdt.2022.103133DOI Listing

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