Effect of Low-level Laser Therapy on Post-bleaching Sensitivity and Color Change

Objective: The objective of this clinical study was to evaluate low-level laser (LLL) therapy in tooth sensitivity and in effecting color change after in-officer bleaching treatment across three weeks of treatment. Methods: Twenty-one volunteers were evaluated through the split-mouth model, so that the right and left maxillary/mandibular quadrants were randomized and allocated to one of two groups: GPLACEBO - the laser tip was positioned without the emission of light (placebo effect) + tooth bleaching with 35% hydrogen peroxide (HP); GLASER - treated with LLL + tooth bleaching with 35% HP. To assess tooth sensitivity, a modified visual analogue scale (VAS) was used after an evaporative stimulus (stimulated pain) and a daily pain questionnaire (unstimulated pain) was also applied. A spectrophotometer was used to measure the color. Three bleaching sessions were performed, with intervals of 7 days. Sensitivity results were tested using Friedman test for intra-group evaluation and Wilcoxon test for inter-group evaluation and ANOVA for color change.