Comparative analysis of Enterococcus faecalis biofilm formation on different substrates

摘要

Introduction: The aim of this study was to compare Enterococcus faecalis biofilm formation on different substrates. Methods: Cell culture plates containing growth medium and E. faecalis (ATCC 29212) were used to grow biofilm on bovine dentin, gutta-percha, hydroxyapatite, or bovine bone. Substrates were incubated at 37??C for 14 or 21 days, and the medium was changed every 48 hours. After the growth induction periods, specimens (n = 5 per group and per induction period) were stained by using Live/Dead, and the images were analyzed under a confocal microscope. The total biovolume (??m3), live bacteria biovolume (??m3), and substrate coverage (%) were quantified by using the BioImage-L software. Results obtained were analyzed by nonparametric tests (P =.05). Results: Biofilm formation was observed in all groups. Gutta-percha had the lowest total biovolume at 14 days (P .05) and hydroxyapatite the highest at 21 days (P .05). No significant difference was observed in green biovolume at 14 days. At 21 days, however, hydroxyapatite had the highest volume (P .05). The percentages of coverage were similar among all substrates at 21 days (P .05), but at 14 days, bovine bone presented the highest coverage (P .05). Conclusions: E. faecalis was capable of forming biofilm on all substrates during both growth periods; hydroxyapatite presented the highest rates of biofilm formation. The type of substrate influenced the biofilm characteristics, according to the parameters evaluated. ? 2013 American Association of Endodontists.