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目的研究牙髓－牙本质复合体超微结构的老年性特征，探讨牙衰老临床表现的机理，并为抗衰老研究提供形态学基础。方法应用透射电镜观察青幼组（１～６月龄）和老年组（１８～２４月龄）Ｗｉｓｔａｒ大鼠切牙牙髓－牙本质复合体主要成分的超微结构。结果老年大鼠造牙本质细胞核出现切迹，内含大量异染色质；高尔基复合体、粗面内质网和线粒体水肿、空泡化，最后消失，胞浆内未见脂褐素；相邻细胞间隙扩大，并出现环层样小体，最后细胞连接松解、分离；牙本质钙盐增加，脱钙时间延长；胶原原纤维增粗、横纹消失、数量增加；牙本质小管缩窄、阻塞、减少，界膜退变。结论牙髓－牙本质复合体超微结构的衰变与其它组织基本相同，细胞内不出现脂褐素和细胞间隙出现环层小体可能是该组织衰老的独有特征。
Objective To study the age-related features of the ultrastructure of dental pulp-dentin complex, to explore the mechanism of aging clinical manifestations and to provide morphological basis for anti-aging research. Methods The ultrastructure of the dental pulp-dentin complex in the young rats (aged 1 ~ 6 months) and the aged group (18 ~ 24 months) of Wistar rats was observed by transmission electron microscope. Results The dentate nuclei of aged rats showed a notch with a large number of heterochromatin. Golgi complex, rough endoplasmic reticulum and mitochondria edema were vacuolized and finally disappeared, while no lipofuscin was found in the cytoplasm. Cell gap expanded, and the ring-like bodies appear, and finally cell lysis, separation; dentin calcium, decalcification time; collagen fibrils thickening, horizontal stripes disappear, the number increased; dentinal tubules narrowed, Obstruction, decrease, degeneration of the membrane. Conclusions The decay of ultrastructure of dental pulp-dentin complex is basically the same as that of other tissues. There is no lipofuscin in the cell and the presence of the annular body in the intercellular space may be the unique feature of the tissue aging.