title: Photoradiation and orthodontic movement: experimental study with canines.
abstract: OBJECTIVE
  The aim of this study was to evaluate, through a double-blind study, the effect of gallinium-aluminium- arsenic (GaAlAs) laser irradiation on the speed of orthodontic movement in canine premolars.
  
  
  METHODS
  Eighteen dogs were divided into two groups, and their third molars were extracted. An orthodontic device was placed between the first molar and the second premolar for stabilization purpose. Group I was irradiated with a dosage of 5.25 J/cm(2) on the right side, whereas the left side was used as the control group. Group II was submitted to the same procedure, but was irradiated with a dosage of 35.0 J/cm(2). Irradiations were done every 7 days, for a total of nine irradiations. The orthodontic space was measured every 21 days.
  
  
  RESULTS
  The 5.25 J/cm(2) dosage accelerated orthodontic movement during the first observation period, from 0 to 21 days (p < 0.05), whereas the 35.0 J/cm(2) dosage retarded the orthodontic movement in the treated group when compared with the control group, during both the first and second observation periods, from 0 to 42 days (p < 0.05).
  
  
  CONCLUSIONS
  The results suggets that photoradiation may accelerate orthodontic movement at a dosage of 5.25 J/cm(2), whereas a higher dosage, 35.0 J/cm(2), may retard it.
authors.affiliation: University of the South of Santa Catarina (UNISUL), Tubarão, Brazil.
authors.forename: Carlos Sechi
authors.initials: CS
authors.lastname: Goulart
authors.forename: Paulo Roberto Aranha
authors.initials: PR
authors.lastname: Nouer
authors.forename: Laura
authors.initials: L
authors.lastname: Mouramartins
authors.forename: Ivana Uglik
authors.initials: IU
authors.lastname: Garbin
authors.forename: Rosane
authors.initials: R
authors.lastname: de Fátima Zanirato Lizarelli
mesh_terms: D000818:Animals; D004285:Dogs; D004311:Double-Blind Method; D007834:Lasers; D014087:Tooth Movement Techniques