应用透射电镜观察了大鼠切牙牙本质超微结构的老年性改变。老化牙本质胶原原纤维的横纹模糊不清，数量增加，口径增粗，分布致密，走向随意；牙本质基质的钙盐沉淀增加，脱钙时间延长；牙本质小管数量明显减少，管内界膜变性退化，管腔缩窄、阻塞和消失，出现少管区和无管区；管闭塞物的大小、形状及其与管壁间的关系各种各样。本文还就其改变机理进行了讨论。 Transmission electron microscopy was used to observe the age-related changes in dentin ultrastructure in rat incisors. Aging dentin collagen fibrillation stripes fuzzy, increased in number, diameter thickening, dense distribution, to random; dentin matrix calcium precipitation increased, decalcification time; significantly reduced the number of dentinal tubules, the inner limiting membrane Degeneration and degradation, lumen constriction, obstruction and disappearance, there is less area and no area; tube occlusion size, shape and the relationship between the tube wall in a variety. This article also discussed the mechanism of change.