牙颈部非龋性硬化牙本质粘接的超微形态研究

目的观察牙颈部非龋性硬化牙本质经自酸蚀牙本质粘接剂处理后，树脂一牙本质界面的超微结构。方法选择有典型牙颈部非龋性缺损且因牙周病拔除的上颌前磨牙，使用两步法的自酸蚀粘接剂Contax粘接处理。扫描电镜观察硬化牙本质表面超微形态以及树脂一牙本质界面的混合层和树脂突的微观表现。结果硬化牙本质的牙本质小管大部分被柱状的矿化结晶体堵塞。粘接界面也可见到清晰的混合层和树脂突，但树脂突较短。结论硬化牙本质的粘接与正常牙本质存在差异，牙本质小管内的矿化结晶可能影响粘接效果。自酸蚀粘接剂对硬化牙本质具有一定的粘接能力。

Ultrastructural study of a self-etching adhesive to sclerotic dentin in non-carious cervical lesions

Objective To examine,in vitro study,the ultrastructure of resin-infiltrated sclerotic dentine following the application of a two-step self-etching dentin adhesive. Methods Non-carious,natural cervical sclerotic lesions were bonded using Contax(DMG Hamburg,Germany),a self-etching dentin adhesive.Artifically prepared wedge-shaped lesions were also made in sound bicuspids and bonded using the same adhesive as controls.By SEM examination,the morphological change of the dentin surface treated by Contax Primer,and the hybrid layer and resin tag in the dentin-resin interface were studied. Results Most dentinal tubules were occluded by rod-like sclerotic casts in the sclerotic dentin surface.Both hybrid layer and resin tag were observed in sclerotic dentin.The hybrid layer was almost similar to that in the sound dentin,but the resin tags were shorter than those in controls. Conclusions Bonding to sclerotic dentin is different from sound dentin and may be compromised by occluded dentin tubules.Based on the present ultrastructural features of hybrid layer and resin tags,the Contax,a self-etching dentin adhesive with a low pH value primer,may have some bonding efficacy to sclerotic dentin.