草酸铁溶液处理牙本质后黏结界面的超微形态

背景：基于流体动力学说，选择良好的生物材料封闭暴露的牙本质小管口是国际上对治疗牙齿敏感研究的热点。草酸铁溶液可以在牙本质小管内形成结晶样结构。 目的：观察草酸铁溶液结合全酸蚀黏结系统处理牙本质后黏结界面的形态学变化。 方法：选择无龋人离体智齿12颗，去除牙冠牙釉质，暴露牙本质。随机均分为实验组和对照组， 32%磷酸酸蚀剂酸蚀牙本质黏结面，实验组用5.3%草酸铁溶液处理表面1 min后充分冲洗10 s，两组表面再充填树脂。平行牙长轴方向片切制备扫描电镜试样，在扫描电镜(SEM)下观察黏结界面的微观形态。 结果与结论：实验组草酸铁产生的结晶样结构几乎堵塞全部牙本质小管开口，树脂层伸出无数短小树脂突嵌于硬化的牙本质小孔内。对照组局部区域混合层与其下方未脱矿的牙本质间有明显的裂隙出现，树脂突较粗，但长短不均匀，可见树脂突的断裂。提示，5.3%草酸铁溶液能够在牙本质小管内形成结晶，使牙本质小管口封闭良好。对照组可见树脂突的断裂，牙本质小管暴露，封闭不严密。说明5.3%草酸铁溶液结合全酸蚀黏结系统治疗牙本质龋能够提高其临床治愈率。

Ultrastructural study of dentin interface disposed by oxalic acid iron solution

BACKGROUND: Total-etch technology is often used to dentin caries, but there are postoperative sensitivities. Crystals can form in dentin tubules after oxalic acid iron solution is used on dentin. OBJECTIVE: To study the micromorphological characteristics of dentin bonding interface after usage of 5.3% acid iron solution linking with total-etch technology to guide clinical therapy. METHODS: Twelve extracted human molars which were eliminated enamel were divided into experimental group and control group. 5.3% acid iron solution was used to experimental group. According to the manufacturer instructions, Chrisma B20 was adhered to the dentin interfaces. All the ultrastructures of dentin bonding interfaces were observed with scanning electronic microscope. RESULTS AND CONCLUSION: Most of the dentin tubules were occluded by crystal-like structures in experimental group. Lots of short resin protrusions walked from resin layer to harden dentin. In the teeth which were only used total-etching, there was obvious crack between local mixture layer and the dentin. Resin protrusions were thick and uneven. There was resin crack. 5.3% acid iron solution could product crystal-like structures in the dentin tubules. The resin tag was broken and the dentinal tubules were open in control group. Postoperative sensitivity of experimental group can be less than that of control group.