Morphology of bacterial flora in root canals associated with apical abscesses  

作　　者：Guo Huijie Gao Chengzhi Zhang Chengfei Zheng Shuying Yue Lin 

机构地区：[1]Department of Stomatology, People's Hospital, Peking University, Beijing 100044, China [2]Electron Microscopy Labrotary (Zheng SY), People's Hospital, Peking University, Beijing 100044, China Electron Microscopy Labrotary , People's Hospital, Peking University, Beijing 100044, China [3]Comprehensive Dental Care, Endodontics, Faculty of Dentistry,University of Hong Kong, Hong Kong, China [4]Department of Cariology, Endodontology and Operative Dentistry,Peking University School and Hospital of Stomatology, Beijing100081, China

出　　处：《Chinese Medical Journal》2014年第18期3254-3258,共5页中华医学杂志（英文版）

基　　金：This study was supported by a grant from National Natural Science Foundation of China （No. 8107088）.

摘　　要：Background Apical abscess is an inflammatory process in the peri-radicular tissues caused by biofilms in the necrotic root canal systems. Therefore, a comprehensive analysis of the bacterial colonization is required for a better understanding of the pathogenesis. This study aimed to investigate the patterns of bacterial infection of root canals of teeth with apical abscesses and to determine whether histological and microbiological findings correlated with clinical conditions. Methods Eighteen samples from 18 teeth with apical pathological lesions were analyzed. Nine patients with acute apical abscesses experienced severe pain, and nine patients were asymptomatic with a sinus tract. After extraction, each affected root was divided into two halves. One half was processed for histobacteriologic analysis and examined using light microscopy, and the other half was analyzed using scanning electron microscopy （SEM） to determine the patterns of microbial colonization of the root canals. Results The appearance of each sample subjected to SEM was consistent with the histobacteriologic findings despite the presence or absence of clinical symptoms. Intraradicular biofilms comprising cocci, rods, and/or filaments of amorphous materials were observed in the apical third of the main root canals in all samples. The bacterial biofilms covering the main root canal walls also penetrated the dentinal tubules to varying depths. The morphologies of biofilms varied, and a unique pattern of intraradicular infection was not identified. Conclusion Intraradicular infections formed complex and variable multispecies biofilms and their presence did not correlate with clinical symptoms.Background Apical abscess is an inflammatory process in the peri-radicular tissues caused by biofilms in the necrotic root canal systems. Therefore, a comprehensive analysis of the bacterial colonization is required for a better understanding of the pathogenesis. This study aimed to investigate the patterns of bacterial infection of root canals of teeth with apical abscesses and to determine whether histological and microbiological findings correlated with clinical conditions. Methods Eighteen samples from 18 teeth with apical pathological lesions were analyzed. Nine patients with acute apical abscesses experienced severe pain, and nine patients were asymptomatic with a sinus tract. After extraction, each affected root was divided into two halves. One half was processed for histobacteriologic analysis and examined using light microscopy, and the other half was analyzed using scanning electron microscopy （SEM） to determine the patterns of microbial colonization of the root canals. Results The appearance of each sample subjected to SEM was consistent with the histobacteriologic findings despite the presence or absence of clinical symptoms. Intraradicular biofilms comprising cocci, rods, and/or filaments of amorphous materials were observed in the apical third of the main root canals in all samples. The bacterial biofilms covering the main root canal walls also penetrated the dentinal tubules to varying depths. The morphologies of biofilms varied, and a unique pattern of intraradicular infection was not identified. Conclusion Intraradicular infections formed complex and variable multispecies biofilms and their presence did not correlate with clinical symptoms.

关 键 词：apical abscess BIOFILM clinical symptoms dentinal tubules endodontic infection 

分 类 号：R781.3[医药卫生—口腔医学]