Development of an Enterococcus faecalis periapical biofilm model for in vitro morphological study
10.7518/hxkq.2014.04.002
- VernacularTitle:粪肠球菌体外根尖生物膜模型的建立及形态学研究
- Author:
Ridan CAO
1
;
Benxiang HOU
Author Information
1. 首都医科大学附属北京口腔医院牙体牙髓科
- Keywords:
Enterococcus faecalis;
periapical biofilm;
post-treatment endodontic disease
- From:
West China Journal of Stomatology
2014;(4):323-327
- CountryChina
- Language:Chinese
-
Abstract:
Objective This study aims to develop and observe a model system of the periapical biofilm structure of Entero-coccus faecalis (E. faecalis). Methods A total of 24 intact human single-rooted premolars extracted for orthodontic reasons were collected and randomly divided into eight groups (n=3). The specimens were subjected to ultraviolet disinfection, ino-culated with E. faecalis (ATCC 29212) suspension adjusted to 1×108 CFU·mL-1, and incubated at 37 ℃ for 1, 2, and 7 d. Specimen groups were prepared for scanning electron microscope to examine the biofilm formation. The specimens in the confocal laser scanning microscope (CLSM) groups were stained with propidium iodide (PI) and ConA-fluorescein iso-thiocyanate (ConA-FITC) to examine the biofilm formation. The images were randomized, and biofilm coverage (%) was assessed using Photoshop CS5. Results The biofilm coverage (%) on the cementum increased with increasing incubation period. The biofilm coverage of the 7 d group was significantly higher than those of the 1 and 2 d groups (P<0.05). The values of the latter two groups were not significantly different (P>0.05). Dense aggregations composed of E. faecalis and the amor-phous matrix were observed on the root cementum surfaces of the specimens in the 7 d group. The bacteria were stained red by PI, and the matrix was stained green by ConA-FITC under CLSM observation. The biofilm coverage (%) on the samples in the 7 d group was 17.23%±1.52%, showing multi-level space structure and water channels. Conclusion E. faecalis forms bacterial biofilms on the root cementum surface in 7 d. The biofilms were composed of E. faecalis and the amorphous matrix.
