糞腸球菌是根管重新治療的案例中經常被分離出的細菌菌種之一。糞腸球菌可以在根管內形成生物膜。形成生物膜的糞腸球菌對於常用的根管沖洗液及根管內的用藥具有抵抗的能力。本篇研究的目的主要是藉由根管重新治療的病人中，所分離出的糞腸球菌。探討其生物膜形成能力對常用沖洗液包括次氯酸鈉及chlorhexidine 治療後的反應。研究中包括十三位病人在接受根管重新治療時所取得的檢體的比較分析。對這些不同的檢體，分別進行生物膜形成能力的比較及細菌的形態的觀察。由實驗的結果顯示，不同來源的糞腸球菌生物膜形成能力彼此存在差異。具有較佳的生物膜形成能力的糞腸球菌對於根管沖洗液的治療比生物膜形成能力較差的糞腸球菌，具有更好的抵抗及存活能力。共軛聚焦雷射掃描顯微鏡的觀察顯示，生物膜形成能力較佳的糞腸球菌，經過chlorhexidine沖洗後，生物膜的形態維持較為完整。經由實驗的結果顯示，生物膜形成能力較佳的糞腸球菌，可以將細菌包覆在所分泌的生物膜構造中。使得其對於根管治療沖洗液具有較佳的抵抗能力，可能進一步造成根管的持續感染。
Enterococcus faecalisis the most important pathogen leading to persistent and secondary infections of root canal-treated teeth. The formation of biofilm protects E. faecalis from the eradication by intracanal medicaments. The aim of this study was to investigate the role of biofilm in E. faecalis isolated from patients with root canal retreatment in impeding irrigants–chlorhexidine (CHX) and sodium hypochlorite (NaOCl). A total of 13 E. faecalis were isolated from patients with failed root canals retreatment and were enrolled in this study. Microbiological investigation of available E. faecalis isolates was performed by bacterial biofilm assay and morphological observation. Our results showed that the activities of biofilm formation by the E. faecalis isolated from root canals were highly diverse. E. faecalis with higher biofilm activity exhibited more resistant to irrigants than lower biofilm formation strain. Confocal laser scanning microscopy (CLSM) observation showed that bacterial biofilms were intact of higher biofilm E. faecalis upon treated with CHX. These results demonstrated that E. faecalis harbors biofilm formation activity that encapsulated bacteria in extracellular polysaccharide, which may lead to enhanced bacteria resistant to irrigant eradicate, subsequently induced persistent infection in canal roots.
