title: Effect of low-level laser therapy on pain following activation of orthodontic final archwires: a randomized controlled clinical trial.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the efficacy of GaAlAs laser light to reduce pain induced by post-adjustment orthodontic final archwire, compared with a placebo control group, and also to evaluate if there are differences in pain gradient when conventional brackets or self-ligating brackets are used for orthodontic treatment.
  
  
  BACKGROUND
  Previous reports indicate that laser therapy is a safe and efficient alternative to alleviate pain caused in the initial stages of treatment, but there are no studies about its efficacy during the last stages of orthodontic treatment.
  
  
  METHODS
  The initial sample was 60 orthodontic patients from a private practice, treated by straight wire technique, 30 of them with mini brackets Equilibrium(®) (Dentaurum, Ispringen, Germany) and 30 with self-ligation In-Ovation C(®) (GAC/Dentsply, Tokyo, Japan) slot 0.022 inch brackets. The archwires used in the final stage of orthodontic treatment were stainless steel 0.019×0.025 inch, slot 0.022 inch in both groups. In a design of divided mouth, the dental arches were randomly assigned to receive one dental arch irradiation with 830 nm 100mW therapeutic laser (Photon Lase II), for 22 sec (2.2 J, 80 J/cm(2)) along the vestibular surface and 22 sec (2.2 J, 80 J/cm(2)) along the palatal surface of the root in the randomly selected arch. The opposite dental arch received placebo treatment, with the laser light off. Pain was evaluated using a visual analog scale (VAS) after 2, 6, and 24 h, and 2, 3, and 7 days of application.
  
  
  RESULTS
  The time course of pain showed the same tendency in both groups, reaching a peak 24 h after the archwire activation. The application of laser therapy reduced pain for any period of time up to 7 days (p<0.00001) and for any kind of bracket.
  
  
  CONCLUSIONS
  Low intensity laser application reduces pain induced by archwires used during the final stage of orthodontic treatment, without any interference regarding the kind of bracket, as reported by patients.
authors.affiliation: Department of Orthodontics, Universidad del Valle, Cali, Colombia. angela.dominguezc@gmail.com
authors.forename: Angela
authors.initials: A
authors.lastname: Domínguez
authors.forename: Sergio A
authors.initials: SA
authors.lastname: Velásquez
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D028022:Low-Level Light Therapy; D008297:Male; D009969:Orthodontic Wires / Q000009:adverse effects*; D010146:Pain / Q000517:prevention & control*; D010147:Pain Measurement; D014087:Tooth Movement Techniques / Q000009:adverse effects*; D055815:Young Adult