RESUMO
Objective: To investigate the effects of He-Ne laser irradiation on orthodontic bone remodeling. Method: Thirt y rabbits were randomly divided into 6 groups with 5 in each group.Another 5 r abbits with no treatment were used as the unforced control. The animals were a nesthetized with 0.05 mol/L pentabarbetal (2 ml/kg). The maxillary first molar a nd the incisor were connected with coil spring ,fixed with ligature wire. Orthod ontic force of 7.84 N was applied on the teeth.The left side was served as contr ol and the right side received irradiation of He-Ne laser at 20 mW with the wav e length of 632.8 nm. Periodontal tissue samples of the experimental teeth were obtainned 1,3,5,7,14 and 21 days respectively after irradation. Tartrate-resist ant acid phosphatase (TRAP) in the tissues was studied with histochemistry. Results: The activity of TRAP in the irradiated tissues was higher than that in the unirradiated 3 and 7 days after treatment (P