大鼠可吸收羟基磷灰石位点保存后牙槽骨材料力学性能和牙齿移动评价

Mechanical evaluation of resorbable hydroxyapatite in extraction site preservation during rat tooth movement

目的探索大鼠可吸收羟基磷灰石位点保存牙齿移动后的牙槽骨材料力学性能和牙齿倾斜度变化,为正畸治疗提供指导。方法 6周龄SD大鼠30只,拔除左上第一磨牙后,通过查随机数字表分为3组(每组10只),A组拔牙窝内植入可吸收羟基磷灰石,B组植入Bio-Oss骨粉,C组自然愈合作为对照组。4周后,10g牵引力近中移动左上第二磨牙28天至拔牙窝内。应用显微CT评价加力后牙齿倾斜度,纳米压痕测试骨弹性模量和硬度,并进行统计分析。结果牙齿移动后,A组的骨材料力学性能最高(P<0.05),牙齿倾斜度最小。结论可吸收羟基磷灰石位点保存后牙齿移动时,局部牙槽骨的材料力学性能增强,牙齿倾斜度减小。

Objective To investigate tooth inclination and bone mechanical responses in the resorbable hydroxyapatite preserved extraction site during rat tooth movement. Methods Thirty 6-week-old rats were included and the left maxillary first molar of the rats was extracted and divided into three groups, Group A, resorbable hydroxyapatite grafted in the extraction site, Group B, Bio-Oss particles, and Group C, no graft. The maxillary left second molar was moved into the extraction site after 4 weeks＇recovery. Molar inclination and bone mechanical properties were evaluated with micro- computed tomography and nanoindentation during tooth movement. One-way ANOVA analysis was performed to compare the difference at the significance level of P 〈 0. 05. Results After the orthodontic loading, the highest micro-hardness, Young＇ s modulus and lowest molar inclination were observed in Group A （ P 〈 0. 05 ）. Conclusion Resorbable hydroxyapatite increases bone mechanical properties with less tooth inclination in the extraction site preservation during rat tooth movenaent.