【作者】 祁玲玲；

【导师】 邢晓东；

【作者基本信息】 南京理工大学 ， 化学工艺， 2010， 硕士

【摘要】 研究开发具有抗菌功能的树脂基牙科材料是口腔科学中一个长期的发展目标,而常用的牙科树脂单体均没有抗菌活性。季铵盐是一种高效广谱的有机抗菌剂,具有低毒、性能稳定、低腐蚀等特点,并表现出长期的生物学效应。将季铵盐型抗菌单体引入于牙科修复材料高分子体系中,赋予牙科材料有效、持久的抗菌性能,必将对龋病及其它继发细菌感染性口腔疾病的防治产生深远影响。本论文的主要内容包括：设计、合成了交联和非交联型两类可聚合季铵盐类单体,傅立叶红外光谱(FT-IR)和核磁共振波谱(1H-NMR)对产物结构进行了表征。利用在口腔修复医学临床中通用的光固化方法,在树脂基牙科材料中共聚引入季铵盐抗菌单体,制备具有抗菌性能的高分子树脂基牙科修复材料。考察树脂体系中光引发剂、助引发剂等工艺条件对聚合反应的影响,确定了共聚的最佳反应条件。加入交联型抗菌单体的树脂体系双键转化率比非交联单体高17%左右,有利于降低单体的残余,显著提高使用安全性。考察了系列季铵盐单体对常见口腔病菌的最低抑菌浓度(MIC)及最小杀菌浓度(MBC)。选择三种抗菌性较强的单体考察对主要口腔致病菌—变形链球菌的杀菌动力学。利用噻唑蓝比色法(MTT法)测试了MAE-DB和MAE-HB单体的细胞毒性。DMAE-CB、MAE-DB和MAE-HB表现出较强的杀菌性；DMAE-CB在浓度19.2μg／mL(4*MBC)与菌液混合培养10min后,杀菌率可达100%；4*MBC的MAE-DB与变形链球菌接触10min后没有活菌存在；4*MBC的MAE-HB与变形链球菌接触30min后没有活菌存在。MAE-DB和MAE-HB对人牙龈成纤维细胞的半数致死浓度为5μg／mL-10μg／mL,与树脂基质Bis-GMA(4.79gg／mL)的细胞毒性相当。研究了抗菌共聚树脂材料的物理化学特性。修复树脂的硬度随着单体加入量的增加而增大,而加入交联型抗菌单体的树脂硬度更高。所有树脂材料的吸水性均≤40μg／mm3。使用激光共焦扫描显微镜(CLSM)和扫描电子显微镜(SEM)初步研究了共聚改性树脂的抗菌特性。材料通过破坏变形链球菌生物膜的完整性及对生物膜内菌体的活性产生抑制而发挥接触抗菌活性；并对菌体有直接的破裂作用。更多还原

【Abstract】 The development of resinous materials with antibacterial activity, which are more and more widely used in the dental clinic for replacement, has long been the goal of oral science. Unfortunately, the monomers which were usually used as dental materials don’t have antibacterial ability. Quaternary ammonium salts(QAS) not only exhibt good bactericidal properties, but slao have some advantages over other antibacterial agents, including low toxicity, greater stability, low corrosivity and extended residence time of biological activity. In order to provide resin composites with inhibitory properties against subsequent recurrent caries and other oral diseases, the dental maerials with long-lasting antibacterial ability were prepared by immobilization of an antibacterial component in the resin matrix.In this thesis, two series of polymerizable QAS were synthesized and characterized by infrared spectroscopy(IR) and nuclear magnetic resonance(1H-NMR). The resin-based restoratives with antibacterial activity were prepared by ultraviolet(UV) induced photopolymerization, which was usually used in stomatology. The factors, such as initiating agent, coinitiator, which affect free-radical copolymerization, were studied and optimized. The degree of double bond conversion of resin system incomporated with crosslinking antibanterial monomer was 17% higher than the ones which containg non-cross linking monomer. It will be helpful for improving the mechanical properties of resin and reducing the residual monomer.To evaluate the bactericidal activity of the QAS monomers against oral pathogenic bacterium, the minimum inhibitory concentration(MIC) and the minimum bactericidal concentration(MBC) for several species and time-kill kinetics against Streptococcus mutans were determined. The cytotoxicity was measured by MTT method. DMAE-CB、MAE-DB and MAE-HB showed strong antibacterial activity. Time-kill curve showed that all cells were killed by 10min contact with 19.2μg/mL of DMAE-CB. MAE-DB gave 100% killing rate at 4*MBC against Streptococcus mutans within 10min, while all cells were killed after contact with MAE-HB for 30min. The concentration which caused 50% toxocity(ID50) of MAE-DB and MAE-HB for human gingival fibroblasts lies between 5-10μg/mL, which was similar with that of Bis-GMA, the usual dental matrix monomer.The chemical and physical properties of experimental resin specimens containing antibacterial monomers were investigated. Surface hardness of restorative resins raised with the increase of the monomer mass, while the antibacterial resins modified with crosslinked monomer have higher hardness than the ones with usual monomer. Water sorptions of all dental restorative resins were less than 40μg/mm3. The antibanterial activity of an copolymerization adhesive resin was investigated by confocal laser scanning microscope(CLSM) and scanning electron microscope(SEM). The modified dental materials could exert contact antibacterial activity via exerting detrimental effects on the growth and membrane integrity of S. mutans.更多还原