人前磨牙牙髓、牙本质复合体中血管活性肽免疫反应神经纤维的增龄性变化

目的　研究人在不同年龄阶段牙髓、牙本质复合体血管活性肽 (VIP)的表达 ,探讨VIP免疫反应神经纤维的增龄变化与牙衰老和老年牙病间的关系。　方法　收集新鲜健康前磨牙 ,按年龄分为 4组 :青少年 (11～ 2 9岁 )组、中年 (30～ 4 4岁 )组、老年前期 (4 5～ 5 9岁 )组和老年 (6 0～ 71岁 )组。常规石蜡包埋、切片 ,免疫组化与图像定量分析。　结果　随年龄增长 ,VIP阳性神经纤维束变细 ,神经分支减少 ,密度降低 ,深入前期牙本质的范围缩小 ;积分光密度、体密度、线密度、线段长度亦下降 ,各组间积分光密度差异无显著性 ,体密度、线密度、线段长度差异性有显著性 (均为P <0 0 5 )。　结论　随年龄增长 ,牙髓、牙本质复合体中VIP阳性神经纤维数量、分支、密度与分布范围减少 ,这可能是老年人牙感觉迟钝和频发牙髓神经性炎症的结构基础。

Age-related changes of vasoactive intestinal polypeptide (VIP) and its immunoreactive nerve fibres in dental pulp dentin complex of human premolars

Objective To explore the expression and localization of vasoactive intestinal polypeptide (VIP) in human premolars for different age period and the relationship between age-related changes of VIP immunoreactive nerve fibres and dental aging or dental diseases of the elderly in dental pulp dentin complex. Methods Fresh and healthy human premolars were collected and divided into 4 groups according to age. All samples were embedded in paraffin, cut into slices, treated by immunohistochemical method and analysd by quantitative imaging. Results With the age increasing, nerve bundle gradually became thin and the distance of extending into predentin became shorter; nerve branches and nerver tissue density decreased. Integral optical density, length density and volume density in the corosal pulp and line length in the predentin decreased, and there were significant differences among groups in the above items except for the integral optical density. Conclusions The numbers, branches and extent of distribution of VIP immunoreactive nerve fibres decreased with the age increasing. This might be one of structural bases of frequent inflammation attack of nonfacterium in the aging dental pulp.