【作者】 何立志；

【导师】 冯祖德；

【作者基本信息】 厦门大学 ， 无机化学， 2007， 硕士

【摘要】 龋病是人类是最常见的疾病,全世界至少有50%的居民即30亿多人患有龋病。龋病是一种慢性病,不会立即致人死亡,但它能引发很多急性炎症和病灶感染性或免疫性疾病,而且严重破坏人类咀嚼器官导致消化系统功能减退和疾病发生。据世界卫生组织（WHO）统计,因龋病而消耗的人类卫生资源是惊人的,现已将龋病列为影响人类健康的三大疾病之一。牙科修复材料在牙齿修复中起着相当重要的作用。牙科材料发展至今,按其属性可分为金属与非金属两类。前者以银汞合金为代表,后者以复合树脂为主要代表。安全性、生物相容性成为口腔金属材料研究和临床应用的重要问题。腐蚀与合金的生物相容性密切相关。复合树脂耐磨性能较差,不宜用于承受较大咀嚼力区的修复是其致命的弱点;聚合体积收缩导致边缘微漏,增大了继发龋的概率传统的方法涉及到机械去除受影响的部份,用树脂或者是合金材料来填充。为了使传统的修复材料粘附在牙体上,这种方法将不可避免破坏周围健康的牙齿。针对早期的龋损或者是细小的裂隙,它不是理想的方法。最近,日本学者Kazuo等报到了人工合成牙釉质的方法来修复早期牙釉质的龋损,但是这种方法合成的牙釉质的厚度被限定在20μm而且合成的牙釉质没有抗菌活性。DCPD在生物体内作为最终向羟基磷灰石转化的中间过渡相,因此被认为是具有好的生物活性陶瓷之一,它还是所有磷酸钙盐在酸性条件下最稳定的物相。缺钙羟基磷灰石在适当的温度和酸性环境下,在短时间内很快转变为DCPD,而且结晶性很好。针对现代饮食习惯,接触偏酸性食物或饮料机会越来越多,而酸性物质对牙釉质硬度有较大的影响,因此利用DCPD来修复早期龋陨有一定的优势。利用CDHA在酸性条件下在牙釉质表面转变成DCPD,进一步形成涂层,涂层厚度约为60～80μm。涂层借助IR、XRD、EDS、SEM、TEM等手段表征涂层,其显微硬度值约为125（VHN）是正常牙釉质的40%左右,涂层能够与牙釉质较好地结合,其间无明显缝隙。大量的文献也曾报道了Zn²⁺、Cu²⁺等具有一定的抗菌性,对于牙菌斑形成有一定的作用。在DCPD涂层的基础上,改进加入Zn²⁺/Cu²⁺掺杂,形成Zn²⁺/Ca²⁺掺杂的抗菌DCPD涂层。其抗菌活性被测试,抗菌率都接近100%。更多还原

【Abstract】 Dental caries is one of the most common diseases. At least 50% of the population of the whole world, that is more than 30 hundred million, is suffering caries. Caries can give rise to acute inflammation, focal infection or immunological disease. In the meantime, it seriously destroys the masticator, decreases the function of the digestive system and causes the disease of the system. According to the statistics of WHO, the depletion of human hygienic resources due to caries is astonishing. Caries is listed as one of the top three diseases which badly influence the human health.The widely accepted theories available for the pathogenesis of caries are the "chemico-bacterial theory" suggested by Miller in 1890 and the "proteolysis theory" suggested by Gottlieb, Frisbin in 1947 and Pincus et al in 1950. Those theories all involve bacteria destroying and acid demineralization.It is important that to develop dental restorative materials to repair tooth. Up to now, there are two types of dental restorative materials according to their properties. One is the metallic restorations, the other is non-metallic restorations. Dental amalgam is one of the metallic restorations; resin composite material is one of the non-metallic restorations. Amalgam restorations may be preferable to resin composite materials for the restoration of the portion of a posterior tooth subject to considerably greater bitting forces because of strength and wear resistance considerations. But amalgam restorations are subject to the effect of corrosion when exposed to conditions present in the ora cavity. Resin composite restorations are usually chosen for restorative task, but resin composite materials are weaker than metals. Applying these repair materials require mechanical removing of the affected part and filling of the hole with a resin or alloy. These methods will inevitably destroy surrounding healthy tooth to facilitate the adhesion of the filler. So it is not an ideal method in the case of tiny gap and early caries. Recently, K. Onmua et al developed a synthetic enamel method to repair the enamel, but the thickness of this synthetic enamel was limited to 20μm and the repair layer did not have antibacterial activity.A number of studies had reported the relationship between dental erosion and acidic foodstuffs. In addition, a report indicated that the mechanisms of DCPD growth and dissolution were of interest because of the importance of this calcium phosphate in the development of dental caries under acidic condition. DCPD is the most stable calcium phosphate under acidic condition. The aim of this study was the preparation and characterization of an antibacterial and highly crystalline zinc-doped DCPD coating on enamel. DCPD coating was prepared on enamel surface by the rapid growth of high crystalline DCPD crystal under strong acidic condition. The microstructure and hardness of the coating were characterized. The formation of the coating was characterized by FT-IR, XRD SEM, TEM, and EDS. Inhibition of the formation and metabolism of dental plaque by zinc salts has been documented. It has been previously reported the mechanism of inhibition of zinc ions on S. mutans, studies suggested that free zinc ions were responsible and that the inhibition of acid production was corrected with adsorption of zinc on the bacterial. Moreover, zinc ions have been included in several dental products, unlike other potential anti-plaque agents, zinc ions tend to cause no unpleasant clinical side-effects.The antibacterial activity against E. coli was examined and the microhardness was tested.更多还原