唾液蛋白和口腔菌群对复合弓丝抗腐蚀性能影响的研究

For metallic biomaterials exposed to organic environment, the adsorption of protein immediately on the surface and the continuous protein adsorption from the surrounding medium are very important for the function and stability of biomaterials. Both the mechanical properties and the corrosion resistance in inorganic environment of composite arch wire were excellent, while the corrosion resistance and biological safety performance were unknown in organic oral environment, which is full of variety of proteins and bacteria. Before the clinic application of a new type of orthodontic arch wire, it is necessary to study systematically in the organic environment where the biomaterial functions..In this study, the influence of salivary proteins and oral bacteria on the corrosion resistance, biological safety performance of composite arch wire and the efficiency of orthodontic tooth movement were studied, through the static corrosion test, electrochemical corrosion test, stress corrosion test, ion precipitation detection, the coefficient of surface friction detection and anti bacterial corrosion test. The precipitation of metal ion was detected, and the formation mechanism and properties of the passive film on the surface were also analyzed. The results would reveal the interactive mechanism of saliva proteins, bacteria and orthodontic arch wire. It would provide basis for in vivo experiment later and for the clinical application of composite arch wire, and also provide representative path on the surface modification study of Ni-Ti, stainless steel and copper based alloy.

对于接触有机环境的金属生物材料，置入环境后数秒钟表面立即发生的蛋白成分吸附、以及从周围介质持续不断的蛋白吸附，对材料的功能发挥和效能稳定十分重要。复合弓丝机械性能优良，前期研究显示其抗无机环境腐蚀能力强，但口腔中多种有机蛋白和菌群对其抗腐蚀能力和生物安全性能的影响趋势和机制尚且未知，在复合弓丝应用于临床前，有必要通过本研究对其应用的有机环境进行系统的分析。.本研究通过静态腐蚀、电化学腐蚀、应力腐蚀和抗菌腐蚀实验，结合离子析出检测和表面摩擦系数检测等手段，分析弓丝表面钝化膜的性状、性能和形成机制，明确多种唾液蛋白和口腔菌群对复合弓丝抗腐蚀性能、生物安全性能及引导正畸牙移动效率的影响趋势；为复合弓丝的体内实验研究和临床推广应用提供基础，揭示唾液蛋白、口腔菌群和正畸弓丝的相互作用机制，为以正畸弓丝为代表的镍钛基、不锈钢基和铜基合金材料的表面改性方案提供研究路径。

正畸弓丝长期处于复杂的口腔生理环境中，不仅遭受多种无机腐蚀性电解质的侵蚀，口腔中各种有机成分也会对其性能产生影响。本课题通过模拟存在唾液蛋白和口腔菌群等多种有机成分的口腔环境，对复合弓丝进行静态腐蚀、电化学腐蚀、应力腐蚀和抗菌腐蚀实验研究。在对弓丝表面钝化膜的性状、性能和形成机制分析的基础上，对其腐蚀行为进行观察研究，揭示唾液中多种蛋白成分和口腔菌群与复合弓丝腐蚀的交互作用机理，评估其生物安全性能。同时，模拟牙齿正畸过程，构建应力腐蚀模型，明确其对正畸牙移动效率的影响，为复合弓丝的体内实验研究和临床推广应用提供基础。本课题阐明了口腔特殊服役环境下，多种有机成分对正畸弓丝的腐蚀机制，研究结果证实：暴露于蛋白质和机械应力均显著降低不锈钢弓丝的耐蚀性，增加有毒腐蚀产物的释放；添加蛋白质可抑制镍钛弓丝和复合弓丝的腐蚀，但机械载荷抵消了这一效应；溶菌酶涂层能够在不改变复合弓丝原有优良新能的前提下，提高其耐腐蚀性、生物相容性，并赋予表面一定的抗菌性能。本项目实验结果能够指导以正畸弓丝为代表的镍钛基、不锈钢基和铜基合金材料表面抗腐蚀及抗菌改性方案设计，为进一步提升其生物安全性、延长服役寿命进而提高正畸牙移动效率提供新的思路。