Effect of Pamidronate on the Tooth Movement and Root Resorption

Methods: Thirty 8 weeks old, male Wistar rats were used in the present study. Under anesthesia orthodontic appliance which was 9 mm NiTi closed coil spring was placed between Incisors and upper first molar. Control group received normal saline and for experimental group, Pamidronate (1mg/kg) , was injected intraperitoneally .After 21 days rats of control group and experimental group were sacrificed and the upper jaws were dissected and the distance between upper 1st and 2nd molars were measured . Then they were fixed in Formalin 10% solution. After laboratory sequences, vertical section of roots were prepared and stained with Hematoxylin and Eosin .Under light microscope, photographs were taken from root surfaces and the resorptive areas were calculated.

Results: There was significant difference in OTM between the control (0.562±0.168 mm) and the experimental (0.346±0.197 mm) groups (p<0.01 by Student's t-test). Looking to root resorption no significant differences were observed between the control (0.25x10E-2 ±0.172 square millimeter) and the experimental groups (0.26x10E-2 ±0.125 square millimeter).

Conclusions: It seems that Pamidronate can reduce orthodontic tooth movement and will be useful in orthodontic anchorage preparations but in the same duration it is not capable to make any changes in root resorption rate. The present findings are not companion to the nature of bisphosphonates in preventing osteoclastic activities and from that, odontoclastic influence i.e. root resorption. The reason may be concealed in the period of experiment for such a long acting pharmacologic agent.