目的:评价牙本质蛋白聚糖对脱矿牙本质胶原纤维形貌和水合性能的影响。方法:新鲜拔除无龋坏人磨牙牙本质酸蚀后分别用胰蛋白酶和硫酸软骨素酶ABC孵育去除牙本质蛋白聚糖和糖胺聚糖侧链,对照组与实验组处理方法相同,但孵育液中不添加酶。然后在牙本质表面不同润湿状态下用场发射扫描电镜和激光共聚焦扫描电镜分别观察牙本质的微观形貌并评价脱矿牙本质的水合性能。结果:硫酸软骨素酶ABC 和TRY酶处理改变了牙本质的微观形貌,使胶原纤维间距增大。酶处理、牙本质表面润湿性及两者的交互作用均会显著影响脱矿牙本质的厚度(P〈0.0001)。结论:牙本质蛋白聚糖和糖胺聚糖侧链在维持牙本质胶原纤维网的空间结构和水合作用方面均发挥着重要作用。蛋白聚糖、胶原纤维- 蛋白聚糖以及蛋白聚糖-蛋白聚糖间的的亲水性是影响脱矿牙本质围观形貌和厚度的重要因素。
Objective: To evaluate the effect ofproteoglycans on the maintain collagen morphology and hydration status of human dentin. Methods: Caries-free, human third molar dentin was acid-etched and treated with trypsin or chondroitinase ABC to remove the proteoglycans and attached glycosaminoglycans. Controls were prepared in the same manner but without using the enzymes. After digestion, FESEM and CLSM were used to evaluate the collagen morphology and hydration effects of dentin, respectively. Results: Digestion with trypsin or chondroitinase ABC induced enlarged interfibrillar spaces of acid-etched dentin and altered the collagen morphology. The factor enzyme treatment (P〈0.0001) and the factor surface wetness status (P〈0.0001) both significantly affected the thickness of acid-etching dentin. There was also significant difference for the factor interactions (P〈0.0001). Conclusion: Glycosaminoglycans chains and proteoglycans were important in maintaining the spatial structure and hydration status of collagen fibril scaffold. The hydrophilic nature of proteoglycans and the collagen- proteoglyeans and proteoglycans- proteoglycans networks affected the morphology and thickness of acid-etched dentin.