根管治疗失败病例根管内微生物的分子生物学检测

目的:通过对根管治疗失败病例根管内微生物进行分子生物学检测,研究失败病例根管内各种细菌的检出率及优势菌;分析临床症状和体征与特殊微生物的关系.方法:选择40 例根管治疗失败病例共40 颗患牙,根据症状分为疼痛组、窦道组和无症状组,去除根管内充填物,根管内细菌取样,PCR检测鉴定.结果: 根管治疗失败病例根管主要呈混合感染,共检出6 种细菌,粪肠球菌是最常检出的细菌,产黑普氏菌与疼痛、衣氏放线菌与瘘管有一定的相关性.结论:根管治疗失败的主要原因是根管内的微生物感染持续存在,根管治疗失败病例根管内微生物组成有其特殊性.

A molecular biology study on the microorganism within teeth with failed root canal therapy

Objective: To examine the microbial flora within the root canals with failed root canal therapy by PCR test, to identify detection rate of bacteria and the predominant bacteria species, and to determine the association of the various species with clinical features. Methods: Forty roots with failed root canal therapy were selected for this study. According to clinical features the roots were divided into three groups: pain, fistula and symptomless. After removal of the root filling material, the microbial samples were taken from the canal and detected by PCR test. Results: The microbial flora within root canals of teeth with failed root canal therapy was found to be mixed, six kinds of bacteria were detected. Enterococcus faecalis was the most commonly recovered bacteria species. Significant associations were observed between Prevotella nigrescens and pain, while dependablity was observed between Actinomyces israelii and fistula. Conclusion: The main cause of root canal treatment failure is the persistent microorganisms. The composition of bacteria in teeth with failed root canal therapy has its own specificity.