Assessment of a single versus double application of low-level laser therapy in pain reduction following orthodontic elastomeric separation: A randomized controlled trial.

Background: Periodontal ligament (PDL) pain, associated with the insertion of elastomeric separators, is one of the most annoying experiences at the beginning of orthodontic treatment. Low-level laser therapy (LLLT) has recently been suggested as a method of controlling this pain.

Objectives: The aim of this study was to evaluate the effectiveness of LLLT on reducing the pain associated with elastomeric separation and to compare a single dose of LLLT (1 h before the insertion of elastomeric separators) vs 2 doses of LLLT (1 h before and immediately after the insertion).

Material And Methods: This randomized controlled trial was conducted at the Department of Orthodontics, Faculty of Dentistry of University of Damascus and at the Department of Orthodontics of Adib-Allaham Center in Damascus, Syria. The sample population was comprised of 36 patients, aged between 12 and 25 years (mean age: 17 ±3.7 years), and the patients were randomly divided into 2 groups. A split-mouth design was employed. One group received 1 dose of laser therapy 1 h before the insertion of elastomeric separators, whereas the other one received 2 doses of laser therapy - 1 h before and immediately after the insertion of elastomeric separators. A GaAlAs laser with a wavelength of 830 nm and a power of 100 mW was used. The pain levels were recorded using the Visual Analog Scale (VAS) after 1, 6, 24, 48, and 96 h. Student's t-test and the repeated measures analysis of variance (ANOVA) were employed to detect significant differences.

Results: Low-level laser therapy significantly reduced post-separation pain when the experimental side was compared to the placebo side in the single-irradiation group (p < 0.05). Low-level laser therapy significantly reduced separation pain with no statistical difference between single and double irradiation protocols (p > 0.05).

Conclusions: Low-level laser therapy had a positive effect on reducing the pain associated with elastomeric separation, whether it was applied as a single dose before elastomeric separation or as a double dose before and after this procedure.