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

Introduction: Pain is the most common sequela reported by patients undergoing orthodontic treatment. It is a prime concern as despite the desire, the orthodontic treatment is refuted by most patients because of the associated pain and discomfort. Recently, there is an abundance of research going on in the field of orthodontics regarding the causes of orthodontic pain and the measures that could efficiently reduce it. One such method is the administration of lasers to reduce the intensity of pain. Therefore, the aim of this study was to assess the effect of low-level laser therapy on spontaneous pain and pain on chewing caused by elastomeric separators. Method: 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. 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). Conclusion: A single dose of low-level laser therapy is an effective modality in significantly reducing the intensity of both spontaneous and pain on chewing caused after the placement of elastomeric separators. © 2018, Springer Nature Switzerland AG.