movement: a clinical investigation

o bjectives: one major drawback of orthodontic treatment is its long duration due to slow tooth movement and the pain at the onset of treatment following application of forces. there is controversy regarding the efficacy of laser for decreasing the treatment time and pain of orthodontic treatment. the purpose of this study was to investigate the effect of low level diode laser on the rate of orthodontic tooth movement and the associated pain. mat erials and methods : in this double blind randomized controlled clinical trial, 12 or- thodontic patients referring to shahid beheshti school of dentistry for first premolar ex- traction were randomly selected and allocated to gallium aluminum-arsenide laser (ga,al,as diode laser, 880 nm, 100 mw, 5 j/cm2, 8 points, 80 seconds, continuous mode) or control group. the patients initially underwent leveling and alignment using the sectional system. force (150 gr) was applied to each canine tooth via sectional closing loops. the loops were activated every month. the rate of tooth movement and pain were monitored over the treatment period and recorded on days 1, 3, 7, 30, 33, 37, 60, 63 and 67. two-way anova was used for comparison of groups. results : there was no significant difference in terms of tooth movement and pain scores between the irradiated and non-irradiated sides at any time point (p>0.05). conclusion : although laser enhanced orthodontic tooth movement in the upper jaw, we failed to provide solid evidence to support the efficacy of laser for expediting tooth move- ment or reducing the associated pain.