口腔常用金属材料的微生物腐蚀行为研究

The research regarding the corrosion behavior and the biocompatibility of dental metal material is one of the hot topics globally. There are numerous microorganisms present in the oral environment because of the ambient temperature，supply of nutrients such as carbon and nitrogen sources, and a favorable microaerobic environment for both aerobes and anaerobes. The microbes can secrete corrosive products like organic acids to caused M-MIC，while electrochemically active microorganisms are capable of obtaining electrons directly from the metal materials, causing the so-called EET-MIC. However, little is known about the MIC caused by the diverse oral microorganisms, and the potential biosafety concern caused by the released metal ions during the MIC process is neglected and not evaluated. In this work, metagenomics and the electrochemical noise will be used to accurately build up the oral corrosive MIC model and to monitor the MIC behavior of the oral microbes. The biofilm consortia will be collected from the healthy people, the patients with oral caries, and the manually mixed consortia by common pathogens in oral environment. The influence of the microbial difference and diversity on the MIC behavior of dental metal materials and their biocompatibility will be investigated. The proposed work aims to elucidate the MIC mechanism of dental metal materials, which is a meaningful guide to the novel design and application of the dental metal materials.

口腔环境具有适宜的温湿度，充足的碳源、氮源等营养物质供给以及良好的微需氧环境，滋生了大量的微生物,这其中包括了厌氧和好氧的微生物。这些微生物可能会分泌有机酸等腐蚀性代谢产物导致代谢产物类的微生物腐蚀，具有细胞外电子传递能力的微生物会导致传电类的微生物腐蚀。而口腔微生物的多样性导致的口腔金属材料的微生物腐蚀的相关研究少有报道，而其严重腐蚀导致的金属离子溶出可能会导致的生物安全性问题也一直被忽视。拟通过宏基因组测序技术准确构建系统多样性口腔微生物腐蚀模型，采用电化学方法尤其是具有无损原位特点的电化学噪声技术，研究典型的口腔用金属材料研究在常见口腔致病菌、口腔健康人菌斑和患龋齿病人菌斑等微生物环境下的腐蚀行为，深入探讨口腔微生物差异性和多样性对金属材料的微生物腐蚀过程及其对生物安全性的影响机制，阐明口腔微生物腐蚀的机理。本研究对于指导新型口腔金属材料的设计开发及临床应用有重要的理论指导意义。

本项目研究了常见的口腔用金属材料在口腔致病菌、口腔菌斑等微生物环境下的腐蚀行为，采用电化学检测、扫描电镜检测、激光共聚焦电镜检测、离子色谱检测、pH值、定量PCR技术、宏基因组测序技术等方法，系统深入的探讨口腔微生物差异性和多样性对金属材料的微生物腐蚀过程的影响，明确了口腔生物被膜是导致口腔微生物腐蚀的主要原因。去除口腔金属材料上黏附的生物被膜就能有效实现口腔微生物腐蚀的防治，通过引入新型杀菌剂β肽聚物，实现了在其低药物浓度下对口腔生物被膜的杀灭、清除、抑制细菌代谢产酸等作用。研究表明D-氨基酸具有抑制细菌成膜和驱散生物被膜的作用，可以作为杀菌增效剂与杀菌剂联合使用，从而降低杀菌剂的使用量。.上述研究成果对于指导新型口腔金属材料的设计开发、新型抗菌药物的临床应用有重要的理论指导意义。