根管治疗失败病例根管内微生物检测及药敏试验

目的通过对根管治疗失败病例根管内微生物进行培养检测，了解失败病例根管内菌群特征，同时对检测出的细菌进行药敏试验，为临床根管治疗提供参考。方法选择86例根管治疗失败病例共86颗惠牙，去除根管内充填物后，对根管内细菌取样，进行培养和鉴定，用琼脂稀释法对根管内分离的优势菌进行药敏试验。结果根管治疗失败病例根管中微生物菌群组成以兼性厌氧菌为优势菌，主要以1-2种革兰阳性菌为主，肠球菌是最常检出的细菌。失败病例根管内检出的兼性及专性厌氧菌对青霉素G、甲醛甲酚、甲硝唑敏感。结论细菌与根管治疗失败密切相关，根管治疗失败病例根管内微生物组成有其独特性。临床应选择敏感性药物进行治疗。

The study on the microbiologic analysis of teeth with failed endodontic treatment and their antimicrobial susceptibility

Objective To determine the composition of the microbial flora present in teeth after the failure of root canal therapy and to test the antibiotic susceptibility of the most prevalent species, and then to provide the reference for curing infected root canals with sensitive drug. Methods Eighty-six root-filled teeth with persistent periapical radiolucencies were selected for retreatment. After removal of the root-filling material, the canals were sampled with paper points. The samples were grown under aerobic and anaerobic conditions and the bacteria were analyzed, and also drug sensitivity was used to test the antibiotic susceptibility of the most prevalent species. Results Facultative anaerobes was the most prevalent species isolated from canals of root filled teeth. The microbial flora was main of 1 to 2 strains of predominant Gram-positive organisms, Enterococcus was the most commonly recovered bacterial species, Facultative anaerobes and anaerobes were sensitive to benzylpenieillin, FC and metronidazole. Conclusion Bacteria are high correlation with the teeth with failed endodontic treatment, The composition of the microbial flora in teeth with failed endodontic treatment has its own identity. We should cure infected root canals with sensitive drug,