Laser Improves Bone Repair in Rats Treated with Anti-Inflammatory Drugs

Objectives: the aim of this study was to evaluate the action of anti-COX-2 selective drug (celecoxib) on bone repair associated with laser therapy. Methods: a total of 64 rats underwent surgical bone defects in their tibias, being randomly distributed into four groups: Group 1) negative control; Group 2) animals treated with celecoxib; Group 3) animals treated with low level power laser and Group 4) animals treated with celecoxib and low level power laser. The animals were killed after 48 hours, 7, 14, and 21 days. The tibias were removed for morphological, morphometric, and immunohistochemistry analysis for COX-2. Results: Statistical significant differences (p<0.05) were observed in the quality of bone repair and quantity of formed bone between groups at 14 days after surgery for groups 3 and 4. COX-2 immunoreactivity was more intense in bone cells for intermediate periods evaluated in the laser exposed groups. Conclusions: Taken together, such results suggest that low level laser therapy is able to improve bone repair in the tibia of rats as a result of an up-regulation for cyclooxygenase-2 expression in bone cells, even when anti-COX-2 is administrated during surgical procedure.