不同微环境对牙髓再生组织的影响

Influence of different micro-environments on pulp regeneration

目的:体外比较不同微环境下牙髓再生的能力与再生组织结构的差异。方法:根据牙根段和皮质骨段管腔中植入物的不同将32个牙根段和32个皮质骨段,随机各分为4个亚组,每个亚组8个样本,管腔内分别植入血管内皮生长因子(VEGF)复合多肽水凝胶支架、血凝块、多肽水凝胶支架及不植入任何材料的空白对照,随后植入裸鼠背部,8周后取材评价管腔内组织生长和组织结构情况。结果:牙根段和皮质骨段管腔内分别有71%和67%的样本有组织长入,再生组织均为含细胞和血管的疏松结缔组织。牙根段根管腔内再生组织中血管形成的量从多到少依次为VEGF复合水凝胶组、血凝块组、水凝胶组和空白对照组,而皮质骨段管腔内再生组织中有较丰富的血管形成,血管形成的量在VEGF复合水凝胶组、血凝块组、水凝胶组3组之间无明显差异。牙组的根管腔中可见沿着根管内壁排列的成牙本质细胞样细胞,少数细胞顶端有一细长分支伸入牙本质小管中。结论:牙根段根管腔由于牙本质的天然支架作用对微环境中的变化更为敏感,牙本质的特殊结构对再生组织的结构起到重要的作用。

Objective：To observe the ability of pulp regeneration and the difference of renewable tissue regeneration under different micro-environment in vitro.Methods：The vascular endothelial growth factor（VEGF）-hydrogel scaffolds,blood colt and hydrogel scaffolds were implanted into the lumen of the root segment and the cortical bone segment,respectively.Subsequently,they were planted into the back of the nude mice.After 8 weeks,the tissue growth and structure in the lumen were evaluated.Results：HE staining showed that loose connective tissues had formed in the root canal in 71% of the specimens and 67% of cortical bone lumen.The amount of angiogenesis in the regenerative tissues of root canal from highest to lowest were：VEGF-hydrogel scaffolds,blood clot,hydrogel scaffolds and blank control.Angiopoiesis was rich in regenerative tissues of cortical bone,but no significant difference was noted among VEGF-hydrogel scaffolds,blood clot and hydrogel scaffolds groups.Conclusion：The root lumen is more sensitive to the microenvironment changes due to the natural scaffold effect of dentin.The special structure of dentin plays an important role in the structure of regenerative tissue.