The Impact Of Local Injection Of Alendronate On Orthodontic Tooth Movement And Periodontal Tissues In Rats

Part 1 Effect of local administration of Alendronate on orthodontic tooth movement in ratsAbstract: Objective To investigate the effects of local administration of Alendronate on orthodontic tooth movement and periodontal ligament in wistar rats. Methods The left upper first molars of 32 7-week-old male wistar rats were moved mesially with coil spring. Alendronate solution at the concentration of 0.02mmol/L, 0.1mmol/L, 0.5mmol/L was injected into the palatal submucosal area adjacent to the left upper first molar in experimental group every 3 day during the experimental period. Same amount of 0.9% NaCl solution was injected into the same area in control group. The distance of tooth movement was measured on the 0, 1, 3, 7, 10, 14, 17, 21day. The rats were sacrificed on the 21st day, Sections were stained and then observed with microscope. Results 1. The distance of tooth movement in the experimental group was significantly smaller than that in the control group. 2. The number of osteoclasts and cementoclasts on the pressure side in the experiment group was significantly smaller than that in the control group. Conclusions The localized use of Alendronate may be a useful agent for anchorage control and could be a beneficial therapeutic adjunct for orthodontic treatment. Part 2 Effect of local administration of Alendronate on periodontal tissue during orthodontic tooth movement in ratsAbstract: Objective To observe the histological changes of periodontium during orthodontic tooth movement in rats receiving locally administration of Alendronate. Methods 40 wistar rats were devided into two groups randomly. The left upper first molars of the rats were moved mesially with coil spring. Alendronate solution at the concentration of 0.1mmol/L was injected into the palatal submucosal area adjacent to the left upper first molar in experimental group every 3 day during the experimental period. Same amount of 0.9% NaCl solution was injected into the same area in control group. The rats were killed 0, 3, 7, 14 and 21days after force application. Sections were stained and then observed with microscope. Results The number of osteoclasts on the pressure side in the experiment group was significantly smaller than that in the control group on the 3rd ; 7th , 14th and the 21st day. The cementoclasts of the experiment group was significantly smaller than that in the control group on the 7th ; 14th and the 21st day. Conclusion The inhibition of tooth movement may be due to the inhibitory effect of Alendronate on osteoclasts. The risk of root resorption also decreases through the application of Alendronate.