Evaluation of the effectiveness of therapeutic laser control index of patient pain in orthodontic treatment

The objective of this research was to compare the effect single low-level laser therapy (LLLT) irradiation on pain perception in patients having fixed appliance treatment in the clinic of postgraduate discipline Orthodontics Department, Araraquara-UNESP. Sixty-two patients with mean age, 19.7 years, were recruited to participate in this randomized, double-blinded, placebocontrolled study. The pacients were assigned to 4 groups: Group I- Laser on the right side; Group II- Placebo on the right side; Group III- Laser on the left side; Group IV- Placebo on the left. The laser or placebo was applied before separation, 24 and 48 hours after separation of their first permanent molars in the lower arch. The pain was recorded by a visual analog scale. The data of the pain’s scale was recorded before and after the laser’s or placebo’s irradiation depending on the group, and immediately after separation and then after 24 and 48 hours. Before and after irradiation, the average of the scores of EVA to the placebo group and laser was zero. Just after the separation, the average of the EVA for the placebo group was 1.6, significantly greater than the average of 1.1 registered for the laser Group (p = 0.013). After 24 hours and before the new irradiation, the values registered among the different groups did not show any diferences, with values from 2.2 to 2.6 and placebo groups and laser, respectively. After irradiation, the values dropped to 1.8 and 1.6 not showing differences. After 48 hours, the values continued dropping without any differences. In relation to the gender, only after the first irradiation in placebo group, the female had a level of pain (0.1) significantly higher (p = 0.04) compared to male, and after 48 hours, the group where the laser was applied had a difference (p = 0.04) among the gender with a value of lower pain for men (0.6) than for women (1.6). The laser irradiation to minimize the pain was only effective immediately after application and separation. In general way, there were no differences between the genders, except after the first placebo group irradiation in which the female had a significantly higher level of pain compared to male and after 48 hours, the group where the laser was applied, has a value significantly lower for the masculine gender than for females. The pain cycle observed in this study had its peak in 24 hours, both for laser’s and placebo’s group.