title: Evaluation of Low Level Laser Therapy on Pain Perception Following Orthodontic Elastomeric Separation: A Randomized Controlled Trial.
abstract: BACKGROUND
  Periodontal pain caused by elastomeric separators is a very common problem in the commencement of orthodontic treatment. Previous studies have shown good results in reducing this pain by Low Level Laser Therapy (LLLT) and different protocols of application have been suggested in the literature.
  
  
  OBJECTIVE
  This trial aimed to evaluate LLLT on managing orthodontic pain caused by elastomeric separators and to compare single versus double irradiation in possible pain reduction.
  
  
  METHODS
  A clinical randomized compound (parallel-group and split-mouth design) trial was conducted on 36 patients between 12 and 26 years of age. Elastomeric separators were placed at the mesial and distal surfaces of the first molars in one jaw (upper or lower) for each patient and in only one side of the mouth (the other side served as the placebo side). The trial had two groups: the first group received single irradiation of LLLT [Gallium Aluminum Arsenide (GaAlAs): 830 nm, 4J/cm2, 100mW] immediately after separators insertion, where as the second group received double irradiation immediately after separators insertion and after 24hours. All patients were instructed to rate the level of pain at 1, 6, 24, 48, 96 hours on a Visual Analog Scale (VAS). The student 't' tests, repeated measures ANOVA and LSD post-hoc tests were employed.
  
  
  RESULTS
  LLLT was successful in reducing post-separation pain when the experimental side was compared to the placebo side at all assessment times in each group (p<0.05). There were no statistically significant differences between single and double irradiation groups in terms of pain reduction (p>0.05).
  
  
  CONCLUSIONS
  GaAlAs LLLT application reduced early orthodontic pain caused by elastomeric separators by single or double irradiation.
authors.affiliation: Student, Department of Periodontics, University of Damascus Dental School , Damascus, Syria .
authors.forename: Mai M E
authors.initials: MM
authors.lastname: Almallah
authors.affiliation: Senior Lecturer, Department of Periodontics, University of Damascus Dental School , Damascus, Syria .
authors.forename: Wael H
authors.initials: WH
authors.lastname: Almahdi
authors.affiliation: Associate Professor, Department of Orthodontics, University of Damascus Dental School , Damascus, Syria .
authors.forename: Mohammad Y
authors.initials: MY
authors.lastname: Hajeer
keywords: Double irradiation; Single irradiation; Visual analog scale