Orthodontic tooth movement after inhibition of cyclooxygenase-2

Introduction: The purpose of this study was to compare the effects of a conventional nonsteroidal anti-inflammatory drug, diclofenac (Voltaren [Novartis, Barcelona, Spain]), and a specific cyclooxygenase-2 (COX-2) inhibitor, rofecoxib (Vioxx [MSD, Madrid, Spain]), on the inhibition of dental movement induced with a coil-spring orthodontic apparatus in rats. Methods: Tooth movement was measured on the lateral cranial teleradiographs of 42 male Wistar rats in 6 experimental groups: (1) 50-g coil spring and 2 rofecoxib injections of 1 mg per kilogram of body weight; (2) similar orthodontic procedure and 2 diclofenac injections of 10 mg per kilogram of body weight; (3) the same orthodontic treatment and 0.9% saline-solution injections; and (4), (5), and (6) 100-g coil appliance and the same pharmacological treatment as 1, 2, and 3, respectively. Results: The difference in tooth movement, measured in the control animals after 10 days of 50 or 100 g of orthodontic force application, was not statistically significant. Reduction in tooth movement in 50-g traction groups reached statistically significant differences; both rofecoxib or diclofenac were effective in inhibiting dental movement. The comparison of the 3 groups treated with 100 g of force also reached statistical significance. Both rofecoxib and diclofenac significantly inhibited dental movement, partially in the case of rofecoxib and totally in the case of diclofenac. Nevertheless, no statistically significant difference was found between the effects of rofecoxib and diclofenac. Conclusions: There is no substantial advantage in using selective COX-2 inhibitors compared with nonspecific COX inhibitors to avoid interference with tooth movement during orthodontic treatment in rats.