目的：通过对比分析肾包膜和口腔黏膜环境对小鼠牙胚成牙的适宜度，期望为牙齿再生技术探寻较为理想的培养环境。方法：构建小鼠牙胚肾包膜下及口腔黏膜下移植模型，将14.5 d胚龄（ ED14.5）的胚鼠下颌第1磨牙牙胚分别移入肾包膜及口腔黏膜下，于植入后3、4周取材，进行大体标本观察、组织学切片分析、硬度、弹性模量测定及拉曼光谱分析等，以观察牙胚的成牙情况。结果：（1）牙胚在肾包膜下及口腔黏膜下均可发育成牙齿状结构，但口腔黏膜组在各时点牙冠体积均小于肾包膜组，且牙齿尖窝发育状态不如肾包膜组明显。（2）组织切片染色显示：在口腔黏膜下形成的牙釉质层和牙本质层比肾包膜组薄，成釉细胞及成牙本质细胞分化不明显。（3）在釉质的硬度比较上，仅口腔黏膜4周组的釉质硬度比正常鼠牙低（ P＜0.05）；在釉质的弹性模量比较上，肾包膜下3周后的移植物釉质弹性模量比成年鼠牙略低，但差别无统计学意义（P＞0.05），肾包膜下4周和口腔黏膜下4周后的移植物釉质弹性模量均低于正常鼠牙和肾包膜3周的釉质弹性模量（ P＜0.01）；各组间牙本质的硬度及弹性模量无显著差异（ P＞0.05）。（4）拉曼光谱分析结果显示：2组的拉曼光谱趋势基本一致，在961 cm－1处有最大峰值，但是在2947 cm－1处，口腔黏膜3周组有明显的峰值，远高于其它各组。结论：（1）对于ED14.5的牙胚来说，相对口腔黏膜环境而言，肾包膜下环境培育3～4周更能发育成相对完整的牙齿。（2）口腔黏膜环境所形成牙齿的诸多性状与肾包膜环境下发育的牙齿相比虽有差异，但其对牙胚的生长发育还是具有一定的影响。%AIM:To compare 2 environments , the subrenal capsule and oral submucosa , for producing well-formed teeth from mouse tooth germs and for exploring the ideal environment for tooth regeneration .METHODS: Two groups were set up .Group A was transplanted with the mouse embronic day ( ED) 14.5 first mandibular molar tooth germs into the subrenal capsule , while group B was transplanted with the ED 14.5 first mandibular molar tooth germs into the oral submucosa.After 3 weeks and 4 weeks, the host mice were sacrificed, and the transplanted explants were evaluated with morphologic observation , histological structures , hardness and elastictic modulus tests , and chemical compositions .RE-SULTS:(1) The explants isolated from both environments showed the tooth-like structures, but as to the group B, the crown was smaller, and the shape of the cusps was not significant .(2) HE staining showed that the dentin and enamel in group A were thicker than those in group B in which the ameloblasts and odontoblasts were differentiated not very well .(3) In the test of enamel hardness , only the hardness of 4 weeks in group B was lower than normal mouse tooth .In the test of enamel modulus , the elastic modulus of enamel in 3 weeks of group A was slightly lower than normal mouse tooth , but the difference was not significant .The elastic modulus of enamel in 4 weeks of group A and group B was significantly lower than normal mouse tooth and 3 weeks of group B .The hardness and elastic modulus of dentin in 3 groups was not significant . (4) Raman spectroscopy showed 2 groups grew in harmony in general , they all had the largest peak in the point of 961 cm-1 , but the 3 weeks of group B had an obvious peak in the point of 2 947 cm-1 .CONCLUSION:For the development of ED14.5 tooth germs, we obtain almost the whole tooth in subrenal capsule transplantation after 3 or 4 weeks.The buccal submucosa environment still has a certain influence on the tooth germ development , although there are some differences about the tooth development between this environment and subrenal capsule environment .
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