Clinical evaluation of the effect of the hybrid light source (LED/laser) on the effectiveness of 35 per cent hydrogen peroxide bleaching, tooth sensitivity and temperature variation on the enamel surface

Given the controversies related to the possible benefits that the use of light sources can provide to the bleaching treatment, the aim of this in vivo study was to analyze the effect of the combination of hybrid light source (LED/laser) to 35% hydrogen peroxide in-office bleaching on its effectiveness, tooth sensitivity and temperature variation on the enamel surface. After being informed of the objectives of the study, 22 volunteers were selected and randomly assigned to two different treatments in a split-mouth experimental model: G1 (control) - bleaching with 35% hydrogen peroxide, G2 (experimental) - bleaching with 35% hydrogen peroxide associated with the use of hybrid light source (LED/laser). The color evaluation was carried out in predetermined times (before treatment, 7 days and 14 days after completion of bleaching) with the aid of a color shade scale (VITA® Classical). Tooth sensitivity was assessed by using the visual analogue scale (VAS) before, immediately and 24 h after bleaching. During the bleaching treatment, temperature was recorded by two channels of thermocouple positioned on the buccal surface of the teeth (central incisors and canines). The values obtained for changes in color and temperature were subjected to statistical analysis, and the significance levei was set at 5%. Tooth sensitivity data were evaluated descriptively. The color change results showed no significant differences in bleaching between the two treatment groups (p = 0.177). The variation of the average temperature during the treatments was not statistically associated with color variation (p = 0.079). Immediately after bleaching it was found that 36,4% of the subjects in Group 2 had mild to moderate sensitivity. In Group 1, 45,5% of the volunteers showed moderate sensitivity. In both groups, the sensitivity of the volunteers ceased in 24 hours...