【作者】 孙佳凝；

【导师】 高宁；

【作者基本信息】 四川大学 ， 口腔临床医学， 2003， 硕士

【摘要】 [研究背景]牙科铸造合金因其理想的物理机械性能运用于临床已有几十年的历史，但大量的体内、外实验表明合金材料，尤其是贱金属材料在口腔湿润的环境中易腐蚀并溶解释放出金属离子，存在过敏源性、免疫源性、致基因突变性和致癌性等潜在危害。不同合金材料生物相容性不同，材料的组成、结构、表面性状、溶解释放出的金属离子种类，以及释放出的金属离子量等与上述潜在危害密切相关。国内除几所重点院校进行了短期合金析出产物对组织细胞毒性的定性研究外，长期离子析出情况尚未见报道。国外有学者测定了10个月中合金材料的离子析出量，并认为长时间段的检测才能更好的预测合金的生物相容性。 [目的]通过对国内临床常用的一种贱金属材料—镍铬铍(NiCrDe)合金中每种组成金属元素在不同浸泡液中析出离子量的检测，探讨每种离子析出量随时间改变的趋势和相对析出量较稳定的时间段以及浸泡液种类对析出量的影响关系，为进一步的生物相容性研究奠定基础，同时指导该合金的临床应用。 [材料与方法]本实验采用随机区组设计，使用ICP-AES(电感耦合等离子体原子发射光谱仪)测定分别浸泡于生理盐水和人工唾液两种浸泡液中在不同时间段的金属离子析出量:并用扫描电子显微镜观察离子析出前后试件表面形态的变化。[结果](1)两种浸泡液中，镍铬被(NiCrBe)合金中各离子(除唾液中的Ni离子外)在1，3，7天的析出量的差异无统计学意义。(2)浸泡30天后，生理盐水中的Cr离子，人工唾液中的Ni，Cr离子析出量与前几时间段的析出量的差异有统计学意义，其余离子的析出量变化无统计学意义。 (3)浸泡82天后，各种离子的析出量都有了显著的提高，在生理盐水中一直稳定的CO离子和在人工唾液中一直稳定的Be离子也检测到少量析出。 (4)各时间段，Al、C:离子在人工唾液中的析出量均大于生理盐水中的析出量;Ni、Be离子在生理盐水中的析出量大于人工唾液中的析出量。 (5)通过扫描电子显微镜对比观察发现，合金表面的腐蚀程度随浸泡时间的延氏不断加重，浸泡于生理盐水中的腐蚀程度比人工唾液中的严重，表面较粗糙的部位比光滑处腐蚀严重。 (6)生理盐水中的离子析出总量大于人工唾液中的离子析出总量。I结论} ‘l)随浸泡时间的延长，离子析出量逐渐增多，析出种类逐渐增多。 〔2)生理盐水中的离子析出总量大于人工唾液中的离子析出总量，在生理盐水中离一户析出量为Ni>Be>Cr>AI>Co>Mo;在人工唾液中离子析出量为Ni>AI>Cr>Be>Co=Mo。 (3)电镜的对比性研究结果与离子析出总量的结果相一致。更多还原

【Abstract】 [Background] Because of its good physical and mechanical properties,dental casting alloys have been used in clinical field for decades. However different kinds of alloys have different biocompatibilities which are determined by the quality and quantity of the released cations. It has been documented in vitro and in vivo that some of the released elements have allergic properties, immunological and bacterialogical effects even have carcinogenic or mutagenic possibilities, mostly among the base dental alloys. Quantitative measurements of elemental release are the base for further research about dental alloy biocompatibilities. Limited by the shortage of advanced testing instrument, only a few institutes in our nation developed such research and none of them based their research on long-term tests which was thought by foreign experts to be very important in predicting biocompatibilities of alloys.[Purpose]The aim of the current study is to test whether time and differentimmersion media are factors influencing elemental release from a base dental alloy: Nickel-Chromium-Beryllium alloy and in what degree those factorsinfluencing it. We will also try to find the stable time for each metal when the releasing rate no more increase.As a result,give more support to future research of biocompatibilities and provide guidance for the application of such alloy in clinics.[Material and methods] Standard sized casting NiCrBe alloy were put into different immersion media (physiological saline solution or artificial saliva) randomly. ICP-AES was used to test the elemental release of each component. Observe the surface of alloy before and after immersion by scanning electron microscope.[Results](1) Except the release of Ni in the artificial saliva, all the other elements remain unchanged statistically in the first week.(2) After one month the elemental release of Cr in both media and Ni in the artificial saliva increase statistically.(3) After three months all the elemental release increased significantly among which even the most stable elements: Co in physiological saline solution and Be in artificial saliva have some quantitative release.(4) More elemental release of Ni and Be was found in the physiological saline solution than in the artificial saliva and more elemental release of Al and Cr was found in artificial saliva than in physiological saline solution.(5) Detected by the scanning electron microscope, surface corrosion became severer when the immersion time increased and severer corrosion was found on the testing sample immersed in physiological saline solution than in artificial saliva.(6) The total elemental release in the physiological saline solution is larger than those released in the artificial saliva.[Conclusions](1) With the increase of immersion time, more types of elements were detected and the quantity of each element released were also increased.(2) The total amount released from physiological saline solution is larger than those from the artificial saliva: Ni>Be>Cr>Al>Co>Mo in physiological saline solution and Ni>Al>Cr>Be>Co=Mo in the artificial saliva.(3) The result of comparative research through scanning electron microscope conforms to the total quantity of elemental release.更多还原