根管治疗失败患者感染微生态研究

目的 观察未治疗和根管治疗失败慢性根尖周炎患者根尖周病损组织菌群构成和根管内壁及根外生物膜超微结构,为治疗提供理论依据.方法 选取2018年4月至2019年4月本院牙体牙髓科收治的未经治疗和根管治疗失败的慢性根尖周炎患者40例,分为未经治疗组和治疗失败组,各20例.采集两组患者牙窝内根尖周病损组织,提取细菌DNA,构建...

Microecological study on infection of patients with failed root canal therapy

Objective To observe the microflora composition and the ultrastructure of the inner and outer biomembrane of root canal in the periapical lesions of chronic periapical periodontitis patients with untreated and failed root canal treatment,and to provide theoretical basis for the treatment.Methods 40 patients with chronic periapical periodontitis with no treatment and root canal therapy failure from April 2018 to April 2019 admitted to the department of Endodontics of our hospital were enrolled,and they were divided into untreated group and failed group,with 20 cases in each group.Bacterial composition was determined by 16S r DNA cloning and sequencing.The apices of the two groups were dissected and the ultrastructure of the inner and outer biomembrane of the root canal was observed by scanning electron microscope.Results The detection rate and cloning ratio of G;bacteria in periapical lesion tissues of both groups were higher than those of G;bacteria (P<0.05).The bacteria with higher detection rate in the periapical lesion tissues of the untreated group were Fusobaeterium nueleatum,Dialister invisus,Campylobacter gracilis,and Streptococcus mitis;the bacteria with higher detection rate in the periapical lesion tissue in failed group were Enterococcus faecalis,Haemophilus segnis,Campylobacter gracilis,Fusobaeterium nueleatum,and Dialister invisus.In untreated group,4 cases of patients had bony fossae around the apical foramen,and there was root canal biomebrane in the fossae,which was mainly composed of cocci,while only a small amount of cementum resorption was observed in the rest 16 cases,and no root canal biomebrane formation was observed.In the failed group,different degrees of cementous resorption were observed on the outer surface of the root apex,and there were intermittent island-like or continuous sheet-like root canal biomebrane on the inner wall of the root canal,which was mainly composed of coccus or bacillus.Conclusion The main reasons for the failure of root canal therapy are Enterococcus faecalis-dominated bacterial colonization and the formation of root canal biofilm on the surface.