牙颈部非龋性硬化牙本质经全酸蚀牙本质粘接剂处理后的超微形态

目的:本研究采用扫描电镜观察牙颈部非龋性硬化牙本质经全酸蚀牙本质粘接剂处理后树脂-牙本质界面的超微结构变化.方法:实验组选择因牙周病拔除的有典型牙颈部非龋性缺损的天然双尖牙,使用全酸蚀牙本质粘接剂Scotchbond Multi-purpose处理硬化牙本质表面,并用树脂修复缺损.对照组为正畸拔除的正常双尖牙,人工机械制备牙颈部楔形缺损.扫描电镜观察酸蚀处理后硬化牙本质表面的超微形态改变,以及树脂粘接修复后树脂-牙本质界面的混合层和树脂突的微观表现.结果:牙颈部非龋性硬化牙本质表面的牙本质小管大部分被柱状的矿化结晶体堵塞.全酸蚀粘接剂Scotchbond Multi-purpose不能酸蚀掉小管内的矿化结晶,粘接修复后,硬化牙本质与树脂的界面可见到清晰的混合层和树脂突,混合层的厚度和树脂突的长度与正常牙本质相似,但树脂突的数量较正常牙本质少,树脂突之间交通枝少见.结论:硬化牙本质的粘接特性与正常牙本质存在差异.树脂突的数量及交通枝不足是硬化牙本质粘接强度受限的可能因素.

Ultrastructural study of sclerotic dentin in non-carious cervical lesions disposed by a total-etching dentin adhesive

Objective: To examine the ultrastructure of resin-infiltrated sclerotic dentine following the application of a three-step total-etching dentin adhesive. Methods: Naturally-occurring, non-carious cervical lesions on extracted premolars were bonded using a total-etching dentin adhesive-Scotchbond Multi-purpose. Artificially prepared wedge-shaped lesions were also made in sound premolars and restored using the same adhesive as control. The morphological change of the dentin surface conditioned with the etchant, and the hybrid zone and resin tags in the dentin-resin interface were studied by SEM . Results: Most dentinal tubules were obliterated by rod-like sclerotic casts in the non-carious cervical lesion, and could not be dissolved by Scotchbond Multi-purpose etchant.Both the hybrid zone and resin tags were observed in sclerotic dentin after restoration, although the resin tags were fewer and in lack of communications, the length of resin tags and the thickness of the hybrid zone were almost similar to those of the sound dentin. Conclusion: Bonding to sclerotic dentin is different from sound dentin, and may be compromised by the fewer resin tags and communications.