The Systemic Effect of local Injection of clodronate on orthodontic tooth movement in rats

Abstract

Clodronate is a non N-containing bisphosphonate that inhibits osteoclast maturation and function. The aim of the study was to assess the systemic effect of local administration of Clodronate on orthodontic tooth movement on rats. Two groups of Sparague-Dawley rats were used. Rats in the experimental group were injected with 50 µl of Clodronate solution on the same side every 3 days for 3 weeks and those in the control group received 50 µl saline solution at the same schedule. Two NiTi-coil springs exerting a constant 50 gm-force, were activated across the span from the central incisors to the first right and left maxillary molars. As the first molar tipped mesially, a diastema between the first and second molars was created. A histomorphometric analysis was used to calculate the mineral apposition rate (MAR) and the diastema between the maxillary first and second molars. The results indicate that (i) average diastema was less in Clodronate injection side group (ii) MAR was less in Clodronate injection side (iii) neither the appliance placement nor the injection inhibited the rat's ability to gain weight. Further study is necessary to determine the reproducibility of these effects.