海藻酸钙凝胶对牙本质小管封闭作用的实验研究

摘要

为治疗牙本质过敏症,研究了海藻酸钙对牙本质小管的封闭作用及矿化效果。以海藻酸钠（SA）,碳酸钙,葡萄糖酸内酯（GDL）为原料,在牙本质上通过原位相转变制备海藻酸钙（CA）凝胶。测定了单一变量条件下不同海藻酸钠浓度、f值（钙离子与羧基的摩尔比）及n值（葡萄糖酸内酯与钙离子的摩尔比）对海藻酸钙凝胶的凝胶化时间和浸提液pH值的影响。扫描电镜观察海藻酸钠混合液处理前后牙本质微观形貌改变,并对封闭后牙本质小管进行了矿化研究。结果表明海藻酸钠浓度为2.5%、f=0.5及n=0.6为最佳配比。海藻酸钠处理后,开放的牙本质小管明显变小或封闭,显示海藻酸钠溶液可进入牙本质小管形成凝胶,并封闭牙本质小管。矿化后凝胶表面呈致密的矿化层,XRD分析为单一的高结晶羟基磷灰石,CA凝胶有利于诱导高结晶度HA的生成,为继续探索牙本质的仿生矿化提供新思路。%This study investigated the role of calcium alginate gel in the occlusion and mineralization of dentinal tubules to treat dentine hypersensitivity.Calcium alginate gel was formed from sodium alginate（SA）,calcium carbonate and gluconolactone（GDL） by in situ phase transition on dentin.The gel formation time and the pH value of the extract were measured with changes in a single variable of calcium alginate concentration,f value（the molar ratio of calcium ion and carboxyl） or n value（the molar ratio of GDL and calcium ion）.The structure and morphology of dentinal tubules were observed by scanning electron microscopy（SEM） before and after the calcium alginate treatment.The results showed that the gel formation was optimized at sodium alginate concentration of 2.5%,f value of 0.5 and at n value of 0.6.The open tubules became narrower or occluded after the calcium alginate treatment.Layers of dense mineral deposits were seen on the surface of the gel in the dentinal tubules.The XRD analysis demonstrated that the mineral deposits were highly crystallized hydroxyapatite（HA） only.Altogether,our results indicate that calcium alginate mixture occludes the dentinal tubules by intratubular gel formation,and that the formed gel induces the deposit of highly crystallized HA providing a new way of further exploring the dentin biomineralization.