Local injection of ligustrazine influences the expression of osteoprotegerin in the maintenance phase in rats with orthodontic tooth movement / 中国组织工程研究

ABSTRACT

BACKGROUND:Ligustrazine has been shown to restore the function of the femoral headviathe revascularization, increased blood flow, theabsorption ofnecroticbone, and bone regeneration. OBJECTIVE:To study the effects of ligustrazine on remodeling of periodontal tissues and the expression of osteoprotegerin in the maintenance phase in rats with orthodontic tooth movement. METHODS:Thirty-two healthy male Wistar rats were included and equaly randomized into four groups. Maxilary left first molar mesialization was performed through traction of 50 g force for 21 days to establish the rat model of tooth movement. 5, 10, 15 mg/L ligustrazine (50 μL) were localy injected into the first molar periosteum in model rats on the day before removing the orthodontic forcing device. Same volume of saline was injected in the control group. The injection was administered every other day. At 1 and 4 weeks after injection, the distance of tooth movement, the recurrence distances and percentage were determined and calculated. The pathological changes in periodontal tissues were observed by immunohistochemistry and hematoxylin-eosin staining. The width ofthe parodontium and number of osteoblasts were observed under an optical microscope. RESULTS AND CONCLUSION:The recurrence distance inthecontrol group was increased compared withtheexperimental group, while the number of osteoblasts and osteoprotegerin immunoreactivity were decreased. Good width of the parodontium and smal recurrence trend were found in 10mg/L ligustrazine group. These findings indicate that ligustrazine promotes the proliferation of osteoblasts and enhances the expression of osteoprotegerin, which is beneficial to the retention of teeth after orthodontic surgery.