LED photobiomodulation effect on the bleaching-induced sensitivity with hydrogen peroxide 35%—a controlled randomized clinical trial

Objectives The aim of this study was to evaluate the effect of a protocol of photobiomodulation (PBM) with light-emitting diodes (LED) on the clinical risk of bleaching-induced sensitivity. Materials and methods Sixty-four volunteers were selected and randomly divided in two groups, placebo (PG) and LED (LG). The LG received PBM irradiation and tooth bleaching, while the PG received tooth bleaching and simulation of the irradiation. The occurrence of painful sensitivity was recorded during the dental bleaching; immediately after bleaching; and 24, 48, and 72 h after tooth bleaching. At the same measurement times, data were collected on the intensity of sensitivity (VAS and NRS scale) and teeth affected by bleaching-induced sensitivity. A questionnaire sought to measure how the painful sensitivity influenced basic daily activities. Tooth color measures were performed using subjective and objective methods. Results LED irradiation decreased the occurrence of sensitivity at all studied evaluation times as well as its intensity, with the exception of the 72-h data when both groups presented no difference. Teeth affected by bleaching-induced sensitivity were significantly greater in the PG. Color measurements presented no differences between the groups in the recently after and later measures. Conclusions PBM with LED decreases sensitivity risk and sensibility intensity during and after office bleaching and causes no influence on the shade degree of whitening achieved. The decrease in tooth sensitivity provided more comfort and less suffering while drinking. Clinical relevance LED irradiation is a promising intervention in the control of bleaching-induced sensitivity. Trial registration RBR-7hpfwj. Graphical abstract Sensitivity intensity measured by the VAS scale (0-10) in the first whitening session (Graphic A) and second whitening session (Graphic B). Significance level set at ≤ 5%. *Mann-Whiteney U test. Columns followed by the same letter are significant different (ap < 0.001; bp < 0.001; cp < 0.001; dp =0.013; ep < 0.001; fp < 0.001; gp < 0.001; hp = 0.002).