大鼠切牙牙髓复合体的透射电镜研究

A TRANSMISSION ELECTRON MICROSCOPIC STUDY ON THE DENTAL PULP COMPLEX FROM RAT INCISOR

用透射电镜观察了大鼠切牙牙髓复合体的超微结构。前牙本质和牙本质的胶原原纤维分粗、细两种：从前牙本质至牙本质；从牙本质小管周围至其远方，纤维由细变粗、由稀至密。胶原原纤维聚集成束，呈纵行、横行和矢状相互交织。前牙本质和牙本质内有许多牙本质小管，内衬鞘样界膜。成牙本质细胞呈长梨形或长纺锤形，核位于基底部，线粒体、粗面内质网、高尔基复合体等位于胞浆的核上区。该细胞突起伸入整个牙本质小管内，含有微丝、微管和小泡等。相邻成牙本质细胞间的牙本质侧有连接复合体相连，其他区域则为桥粒。

The ultrastructure of the dental pulp complex from rat incisor was examined by transmission electron microscopy. There were both thin and thick collagen fibrils in the predentin and dentin. The diameter and the density of collagen fibrils gradually became greater from the predentin to the dentin and from the area near dentinal tubules to the area leaving dentinal tubules. The collagen fibrils were gathered into some bundles which run in longitudinal,horizontal,and arrowy direction meeting at right angles with one another and forming network;There were many dentinal tubules in the predentin and the dentin. The lumina of the dentinal tubules were lined with a shee-like limitans. The odontoblasts assumed elongated pear or spindle in shape. Its nucleus was close to the basal cellular region. The mitochondria,rough endoplasmic reticulum,Golgi complex mainly laid in the supranuclear region of the cytoplasm. The odontoblast process was observed in the transverse section of all dentinal tubules of the predentin and the dentin. There were chiefly microtubules,microfilaments and vesicles in the process. There was a narrow space between the odontoblasts. The dentin side between the odontoblasts was connected by junctional complex and the other area was connected by the desmosomes.