Effects of endothelin antagonist tezosentan on orthodontic tooth movement in rats

Introduction: Endothelin is a cytokine peptide present in the periodontal ligament in physiological conditions. Its concentration in the periodontal ligament doubles after 3 hours of axial loading of a tooth. The role of endothelin in orthodontic tooth movement has not yet been explained. We tried to determine the effect of tezosentan, a specific dual endothelin receptor antagonist, on orthodontic tooth movement in rats. Methods: Twenty-one rats were divided into 3 groups (n = 7). In the tezosentan group, closed-coil springs were placed, and the animals were treated daily with tezosentan; in the coil-spring group, closed-coil springs were placed, and the animals were treated with an inert physiological solution. The appliance was placed between the maxillary left first molar and the incisor. The third group was the control group. On days 0, 7, 14, and 25, the distances between the maxillary molars and incisors were measured at the experimental and contralateral sides. Results: Changes in measured distances at the experimental sides were significantly different between the tezosentan and the coil-spring groups on day 25 (P < .001), with the tezosentan group showing greater changes in the measured distances. There were no differences between the tezosentan and the coil-spring groups at the contralateral side. In the control group, the measured distance increased at both sides (P < .001). Conclusions: Tezosentan, an endothelin dual antagonist, enhanced tooth movements in rats.