Enterococcus Faecalis Biofilm. Formation and Development in Vitro Observed by Scanning Electron Microscopy

Area of Science:

• Microbiology
• Dental Research
• Biomaterials

Background:

• Enterococcus faecalis is a common bacterium found in root canal infections.
• Bacterial biofilms contribute to persistent infections and treatment failure.
• Accurate detection of biofilm formation is crucial for understanding and managing endodontic infections.

Purpose of the Study:

• To evaluate and compare different fixation methods for detecting Enterococcus faecalis biofilms on microplates.
• To determine the optimal fixation technique for quantifying biofilm formation.
• To correlate microplate-based detection with scanning electron microscopy (SEM) findings.

Main Methods:

• Enterococcus faecalis biofilms were cultured on microplates and stained with crystal violet.
• Three fixation methods were tested: no fixation, heat fixation, and 10% formaldehyde fixation.
• Biofilm quantification was performed using a microplate reader.
• Root portions were incubated with E. faecalis and analyzed using SEM at various time points.

Main Results:

• 10% formaldehyde fixation yielded significantly higher biofilm detection compared to heat fixation or no fixation (ANOVA p<0.0001).
• SEM analysis revealed consistent E. faecalis growth and confirmed biofilm development starting from 14 days of incubation.
• Formaldehyde fixation proved to be the most effective method for detecting E. faecalis biofilms on microplates.

Conclusions:

• 10% formaldehyde fixation is the superior technique for detecting Enterococcus faecalis biofilms in vitro.
• SEM corroborates the microplate findings, indicating biofilm formation is established by 14 days.
• This study provides a reliable method for assessing E. faecalis biofilm development in endodontic research.