Effect of ultrasound on osteoprotegerin and receptor activator nuclear factor kappaB ligand expression during root resorption in rats / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the effect of pulsed ultrasound on the expressions of osteoprotegerin (OPG) and receptor activator nuclear factor kappaB ligand (RANKL) during root resorption in a mouse model of orthodontic tooth movement.</p><p><b>METHODS</b>Thirty-two male Wistar rats (6-8 weeks old) were randomly assigned into 4 equal groups, including the blank control group, two ultrasound exposure groups with daily local LIPUS stimulation (100 and 150 MW/cm(2)) for 10 days during mechanical loading, and the control group with mechanical loading but not LIPUS exposure. Nickel-titanium closed-coil springs were used to generate 100 g mesial force for 10 days to move the maxillary right first molars. The expression of OPG and RANKL proteins at the compression sites was detected by immunohistochemistry.</p><p><b>RESULTS</b>Ultrasound stimulation significantly up-regulated the expression of OPG and down-regulated RANKL expression (P<0.05). The expressions of OPG and RANKL showed significant differences between the two ultrasound exposure groups (P<0.05).</p><p><b>CONCLUSION</b>Ultrasound stimulation might be useful to protect against root resorption and accelerate its repair by regulating the expressions of OPG and RANKL.</p>