Evaluating the effect of low-level laser therapy on pain induced by orthodontic separation: a randomized split-mouth clinical trial

Forty patients were randomly selected for this single-blind, split-mouth study. Elastomeric separators were placed mesial and distal to the permanent first molars in all the four quadrants. The arches were divided into experimental and control sides. The experimental side was treated with low-level laser therapy on two points on the buccal and lingual mucosa for 20 s each, with a 940-nm gallium-aluminum-arsenic diode laser on continuous mode and power set at 200 mW. The other side received placebo laser therapy without turning on the laser. A visual analogue scale was used to assess the intensity of spontaneous pain and pain on chewing, and the subjects were asked to mark the pain scores in a questionnaire given to them at different time intervals. The independent samples t test and analysis of variance with the post hoc Tukey test was used to analyze the results.

The subjects reported less intensity of pain on chewing as well as spontaneous pain at the sites which were given low-level laser therapy as compared to the placebo side. The difference between the pain intensity on the low-level laser therapy side and placebo side was found to be statistically significant (p ≤ 0.05).