DEVELOPMENT OF TREATMENT AGENT FOR HYPERSENSITIVE DENTIN BY DENTINE ADHESIVE POLYMERIC LATEX

许多治疗牙本质过敏症的方法一直在研究如何封闭开放的牙本质小管。小管闭塞可降低牙本质的水导，减轻过敏反应。为探索治疗牙本质过敏症的新方法，研制了一种能与牙本质表面发生反应并在表面沉淀的乳剂。即，甲基丙烯酸甲酯(MMA)和对苯磺酸(MS聚合物)的共聚物。MS聚合物可通过离子键合与牙本质发生反应并沉积在表面。用该乳剂(PMS)直接处理无涂抹层和堵塞的模型牙本质，并考察了在牙本质表面形成的聚合物膜的稳定性。PMS的各种处理条件均能有效封闭开放的牙本质小管，即PMS在模型表面聚集并形成一层聚合物膜。在耐久性试验中，PMS处理组的肾小管闭塞能力最强。尽管在原始模型牙本质上可以清楚地观察到牙本质小管，但经前牙本质处理后，这些小管被PMS的沉积完全封闭，而且覆盖在表面的PMS不能通过刷牙去除。结果表明，PMS能与牙本质表面发生紧密反应。这种稳定的主要力量是由于磺酸基与牙本质中的钙离子之间的离子键合。PMS层对质子的渗透性较低，是治疗牙本质过敏症最有效的材料之一。

Many treatment for hypersensitive dentin have been studying to obturate opened dentinal tubules. The occlusion of tubules can decrease the hydraulic conductance of dentin and relieve hypersensitivity. To develop a new treatment method for the hypersensitive dentine, an emulsion which can react with dentine at the surface and precipitate there was prepared. That is, a copolymer of methyl methacrylate (MMA) and p-stirene sulfonic acid (MS polymer). The MS polymer could react with dentin through ion bonding and deposit on the surface. A model dentin free of smear layr and plugs was directly treated with the emulsion (PMS) and the investigated with attention to the stability of the polymer membrane created on the dentin surface. Every treatment conditions with PMS was effective to obturate opened dentinal tubules, that is, the PMS was aggregated and made up a polymer film on model surface. The PMS treatment was the most high ability of occlusion of tubules under the durability tests. Though the dentinal tubules were observed clearly on the original model dentine, the treatment with PMS completely occluded these tubules by the deposition of PMS.Moreover, the PMS covered on the surface was not remove by the brushing. This founding indicated that the PMS could react with the dentin surface tightly. The main force of this stabilization is due to the ion bonding between sulfonate group and calcium ions originated form the dentin. The permeability of protons through the PMS layr was low and it is concluded that the PMS is one of the most effective materials for treatment of the hypersensitive dentin.