根管内感染防治新技术的相关研究
发布时间：2018-08-12 18:48
【摘要】：根管治疗首先是去除根管内感染组织,然后对根管系统进行预备成型和消毒,最后再用生物惰性材料(如牙胶尖)和根管封闭剂对根管系统进行三维的严密充填。完全清除根管内感染对根管治疗成功至关重要。目前,实现这一目标主要借助各种各样的物理-化学根管消毒技术。然而,由于牙根解剖结构的复杂性,应用现有的根管消毒技术完全去除根管及牙本质小管内的细菌几乎是不可能的。残存在根管内的细菌有可能引起根管再感染的发生,从而导致根管治疗的失败。这就要求不断发展更多更有效的根管消毒技术。此外,作为根管治疗的最后一个步骤,理想的根管封闭材料应该能对根管内残存的细菌起到有效的杀灭作用或者抑制作用。因此,本课题的主要目的是探索和发展一些新的根管内感染防治技术,为提高根管治疗成功率、维持根管治疗远期疗效和预防根管治疗失败提供新的思路和技术理论支持。为此,我们进行了如下探索:1.激光辅助根管消毒技术在体外离体牙根管感染模型中消毒作用的相关研究首先,我们构建了粪肠球菌离体牙根管感染模型并在此基础上比较研究了【Nd:YAG激光,Er:YAG激光,Er,Cr:YSGG激光和光动力杀菌治疗技术】等激光辅助根管消毒技术的消毒作用。结果证实以上几种根管消毒技术都能在粪肠球菌离体牙根管感染模型中取得有效的消毒效果;其中又以Er:YAG激光辅助次氯酸钠(NaOCl)的效果最好。但是,同时我们也发现Er:YAG激光辅助NaOCl只能清除根管壁表面和侵入牙本质小管内200微米以内深度的粪肠球菌,而不能清除侵入牙本质小管内300微米以上的细菌。因此,我们又对Er:YAG激光的工作参数进行了优化研究,即比较了不同输出功率(0.3、0.5和1.0 W)和不同照射时间(20和30 s)条件下Er:YAG激光辅助NaOCl根管消毒技术在体外离体牙根管感染模型中消毒作用。结果发现0.5 W/30s是最优化的参数组合;它可以清除侵入牙本质小管内500微米左右深度的粪肠球菌。2.季铵盐化二氧化硅生物玻璃纳米微球抗菌根管封闭剂基质材料的合成及其相关特性研究首先,我们使用溶胶-凝胶法合成了二氧化硅生物玻璃纳米微球(SBG-NS)并使用门舒特金反应法合成了四种不同侧链烷基长度的甲基丙烯酸酯季铵盐(QAMs)。然后使用硅烷偶联剂(KH-570)对SBG-NS进行表面修饰,目的是将碳碳双键引入SBG-NS表面以获得中间产物SBG-NS/KH-570。最后,QAMs与SBG-NS/KH-570表面的KH-570发生聚合反应得到季铵盐化二氧化硅生物玻璃纳米微球抗菌根管封闭剂基质材料(SBG-QAPMs)。然后,我们测定了(1)SBG-QAPMs的水溶性及离子释放能力;(2)SBG-QAPMs对感染根管内常见顽固性致病菌的杀菌作用;(3)SBG-QAPMs的生物安全性(体外细胞毒性作用和体内炎症反应作用)。结果发现,SBG-QAPMs在PBS溶液中的稳定性极好并可以释放微量矿化相关离子(Si4+和Ca2+)、具备长期稳定有效的杀菌作用和良好的生物安全性。综上所述,我们可以得出以下结论:(1)Er:YAG激光辅助NaOCl根管消毒技术(0.5 W/30s)可以考虑用作常规根管消毒技术;(2)SBG-QAPMs可以用于新型长效抗菌根管封闭剂的研发。
[Abstract]:Root canal therapy begins with the removal of infected tissues in the root canal, then the preparation and disinfection of the root canal system, and then the three-dimensional filling of the root canal system with bio-inert materials (such as gutta-percha tip) and root canal sealants. Complete removal of root canal infections is crucial to the success of root canal therapy. However, due to the complexity of root anatomy, it is almost impossible to completely remove bacteria from root canals and dentinal tubules by using existing root canal disinfection techniques. In addition, as the last step of root canal therapy, ideal root canal sealing materials should be able to effectively kill or inhibit the remaining bacteria in the root canal. Therefore, the main purpose of this project is to explore and develop some new root canal infection prevention and treatment. In order to improve the success rate of root canal therapy, maintain the long-term efficacy of root canal therapy and prevent the failure of root canal therapy, we have made the following explorations: 1. Relevant studies on the disinfection effect of laser-assisted root canal disinfection technology in vitro root canal infection model. Firstly, we constructed the faecal-enteroblast. The disinfection effects of laser-assisted root canal disinfection techniques such as Nd:YAG laser, Er:YAG laser, Er, Cr:YSGG laser and photodynamic disinfection therapy were compared and studied on the basis of the model of bacterial root canal infection in vitro. Er:YAG laser-assisted sodium hypochlorite (NaOCl) had the best disinfection effect. However, we also found that Er:YAG laser-assisted NaOCl could only remove Enterococcus faecalis from the surface of root canal wall and from the depth of 200 microns invading dentinal tubules, but could not remove bacteria invading dentinal tubules more than 300 microns. The working parameters of Er:YAG laser were optimized, i.e. the effects of Er:YAG laser assisted NaOCl root canal disinfection on the root canal infection model in vitro were compared under different output power (0.3, 0.5 and 1.0 W) and irradiation time (20 and 30 s). Removal of Enterococcus faecalis invading dentinal tubules at depths of about 500 microns. 2. Synthesis and characterization of quaternary ammonium salt silica Bioglass nanospheres as matrix materials for root canal sealants. Firstly, we synthesized silica Bioglass nanospheres (SBG-NS) by sol-gel method and used Menshutkin reaction method. Four kinds of quaternary ammonium methacrylates (QAMs) with different side chain alkyl lengths were synthesized. Then the SBG-NS was modified by silane coupling agent (KH-570) in order to introduce carbon-carbon double bonds into the surface of SBG-NS to obtain the intermediate SBG-NS/KH-570. Finally, QAMs was polymerized with KH-570 on the surface of SBG-NS/KH-570 to obtain quaternary ammonium salt dimer. Then, we measured (1) the water solubility and ionic release ability of SBG-QAPMs; (2) the bactericidal effect of SBG-QAPMs on common intractable pathogenic bacteria in infected root canals; (3) the biological safety of SBG-QAPMs (cytotoxicity in vitro and inflammatory reaction in vivo). The results showed that SBG-QAPMs were very stable in PBS solution and could release trace mineralization-related ions (Si4+ and Ca2+) with long-term stable and effective bactericidal effect and good biological safety. Root canal disinfection technology; (2) SBG-QAPMs can be used for the development of a new long-acting antibacterial root canal sealer.
【学位授予单位】：第四军医大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R781.05
，
本文编号：2179969
[Abstract]:Root canal therapy begins with the removal of infected tissues in the root canal, then the preparation and disinfection of the root canal system, and then the three-dimensional filling of the root canal system with bio-inert materials (such as gutta-percha tip) and root canal sealants. Complete removal of root canal infections is crucial to the success of root canal therapy. However, due to the complexity of root anatomy, it is almost impossible to completely remove bacteria from root canals and dentinal tubules by using existing root canal disinfection techniques. In addition, as the last step of root canal therapy, ideal root canal sealing materials should be able to effectively kill or inhibit the remaining bacteria in the root canal. Therefore, the main purpose of this project is to explore and develop some new root canal infection prevention and treatment. In order to improve the success rate of root canal therapy, maintain the long-term efficacy of root canal therapy and prevent the failure of root canal therapy, we have made the following explorations: 1. Relevant studies on the disinfection effect of laser-assisted root canal disinfection technology in vitro root canal infection model. Firstly, we constructed the faecal-enteroblast. The disinfection effects of laser-assisted root canal disinfection techniques such as Nd:YAG laser, Er:YAG laser, Er, Cr:YSGG laser and photodynamic disinfection therapy were compared and studied on the basis of the model of bacterial root canal infection in vitro. Er:YAG laser-assisted sodium hypochlorite (NaOCl) had the best disinfection effect. However, we also found that Er:YAG laser-assisted NaOCl could only remove Enterococcus faecalis from the surface of root canal wall and from the depth of 200 microns invading dentinal tubules, but could not remove bacteria invading dentinal tubules more than 300 microns. The working parameters of Er:YAG laser were optimized, i.e. the effects of Er:YAG laser assisted NaOCl root canal disinfection on the root canal infection model in vitro were compared under different output power (0.3, 0.5 and 1.0 W) and irradiation time (20 and 30 s). Removal of Enterococcus faecalis invading dentinal tubules at depths of about 500 microns. 2. Synthesis and characterization of quaternary ammonium salt silica Bioglass nanospheres as matrix materials for root canal sealants. Firstly, we synthesized silica Bioglass nanospheres (SBG-NS) by sol-gel method and used Menshutkin reaction method. Four kinds of quaternary ammonium methacrylates (QAMs) with different side chain alkyl lengths were synthesized. Then the SBG-NS was modified by silane coupling agent (KH-570) in order to introduce carbon-carbon double bonds into the surface of SBG-NS to obtain the intermediate SBG-NS/KH-570. Finally, QAMs was polymerized with KH-570 on the surface of SBG-NS/KH-570 to obtain quaternary ammonium salt dimer. Then, we measured (1) the water solubility and ionic release ability of SBG-QAPMs; (2) the bactericidal effect of SBG-QAPMs on common intractable pathogenic bacteria in infected root canals; (3) the biological safety of SBG-QAPMs (cytotoxicity in vitro and inflammatory reaction in vivo). The results showed that SBG-QAPMs were very stable in PBS solution and could release trace mineralization-related ions (Si4+ and Ca2+) with long-term stable and effective bactericidal effect and good biological safety. Root canal disinfection technology; (2) SBG-QAPMs can be used for the development of a new long-acting antibacterial root canal sealer.
【学位授予单位】：第四军医大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R781.05
，
本文编号：2179969
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