兔磨牙压低过程中牙根吸收与DPP表达相关性的研究

Correlation between root resorption and DPP expression during rabbit molar reduction

目的建立新西兰大白兔磨牙压低致牙根吸收动物模型,检测龈沟液中牙本质磷蛋(DPP)的表达与牙根吸收的关系。方法雄性4个月大的新西兰大白兔66只,随机分成2组:不加力组、加50g力组。在左侧下颌第一磨牙根尖下前方打支抗钉作为强支抗,压低左侧下颌第一磨牙。分别在加力0d、3d、6d、9d、12d、15d、18d、21d、24d、27d、30d提取龈沟液,通过酶联免疫吸附实验(ELISA)检测龈沟液中DPP的浓度,并制备实验牙及其牙周组织切片,行苏木精-伊红染色、抗酒石酸酸性磷酸酶染色,用于观测牙根吸收陷窝面积和破牙骨质细胞数量。结果加50g力组,第0d到6d,DPP浓度逐渐升高,第6d到15d浓度处稳定水平,第15d到第21d浓度又再度升高,第21d到30d浓度降低,组间有显著差异(P <0.01)。根吸收相对面积和DPP浓度存在明显的相关性(P <0.05)。结论 DPP作为牙的特异性蛋白,参与正畸牙根吸收的发生、发展、修复,可以作为一种早期诊断正畸牙根吸收的重要指标。

Objective The root absorption model of New Zealand white rabbit molars was constructed to detect the relationship between the expression of dentin phosphoprotein(DPP) and root resorption in gingival crevicular fluid. Method 66 male New Zealand white rabbits, 4 months old, were randomly divided into 2 groups: non-energized group and 50 g force group. In the left mandibular first molar, the anterior apex is anchored as a strong anchorage, and the left mandibular first molar is depressed. The gingival crevicular fluid was extracted at 0d, 3d, 6d, 9d, 12d, 15d, 18d, 21d, 24d, 27d, 30d, and the concentration of DPP in gingival crevicular fluid was determined by enzyme-linked immunosorbent assay(ELISA). The experimental teeth and their periodontal tissue sections were stained with HE and TRAP for observing the area of root resorption and the number of broken bone cells. Result After continuous force for 30d, the concentration of DPP increased gradually from 0d to 6d, and the concentration was stable at the 6d to 15d. The concentration increased again from the 15d to the 21d, and the concentration decreased from the 21d to the 30d. There was a significant difference between the groups. P < 0.01).The relative area of root absorption was significantly correlated with DPP concentration(P < 0.05).Conclusion The relative area of root absorption was significantly correlated with DPP concentration(P < 0.05).