Microtomographic analysis of the effect of sodium alendronate on orthodontic movement in rats.

Abstract

To evaluate the effect of sodium alendronate on orthodontic tooth movement in rats using microtomographic analysis. Thirty male Wistar rats (Rattus norvegicus) were divided into three groups of 10 rats and administered saline (control), 1mg/kg sodium alendronate or 6mg/kg sodium alendronate, respectively. The drug was administered once per week for 5weeks by gavage. Orthodontic movement was induced during the last 2weeks of medication administration by inserting a closed nickel-titanium spring between the left upper first molar and central incisors. The opposite side served as the control. Tooth movement and bone trabeculation in the furcation region were evaluated by microtomographic analysis in the first (moved) and third (static) molars. The data were subjected to one-way or two-way ANOVA and Bonferroni test (P<.05). The microtomographic images of the group that received 6mg/kg sodium alendronate demonstrated significantly less tooth movement (P=.048), less space between the trabeculae (P=.031) and greater number of bone trabeculae (P=.033) compared to the other groups. There were no statistically significant differences in bone volume and mean trabecular thickness between the three groups. The static teeth did not show the same alterations (P>.05). Sodium alendronate treatment reduced tooth movement in rats.