大鼠牙齿发育过程中牙本质形成的超微结构

THE ULTRASTRUCTURE OF THE DENTINAL DEVELOPMENT IN RATS

目的 :了解牙齿发育过程中牙本质形成的超微结构。方法 :通过透射电镜观察 1 4天 ,2 1天胚胎大鼠和新生大鼠牙本质发育的超微结构。结果 :1 .成牙本质细胞是在成釉器发育到钟状后期由牙乳头细胞分化 ;2 .分化的成牙本质细胞具有活跃的生物合成功能 ,分泌基质 ,产生和释放基质小泡 ;3 .羟磷灰石晶体最初在基质小泡内形成 ,并不断生长最终进入胶原基质沉积钙化 ;4.牙本质形成过程中可见凋亡的成牙本质细胞。结论 :成牙本质细胞形成牙本质 ,牙本质矿化开始于基质小泡 ,细胞凋亡参与牙本质发育过程。

To study the ultruastructure of the dentinal development in rats. Methods: The ultrastructure of the dentinal development of the embryonal rats on the 14th day, 21st day and newborn rats in 10 days were observed by electronic microscopy. Results: 1, The papilla cell differentiated into odontoblast in the later period of clock shape of the enamal organ; 2, The obvious synthetic function, secreting collage matrix and forming and releasing matrix vesicle(MVs) were observed in the differentiated odontoblast; 3, The hydroxyapatite (HAP) was initially in MVs and outleted into collage matrix and eventually minalized; 4, Apoptosis could be observed in the development of the dentin. Conclusion: The dentin were formed by odontoblast; the minalization started in MVs initially; apoptosis may take place in dentinal development.