Enterococcus faecalis biofilms eradication by root canal irrigants

Area of Science:

• Microbiology
• Biomaterials Science
• Dental Research

Background:

• Dental biofilms, particularly Enterococcus faecalis, pose a significant challenge in endodontic treatment.
• Effective biofilm eradication is crucial for successful root canal therapy and preventing persistent infections.

Purpose of the Study:

• To determine the minimal biofilm eradication concentration (MBEC) of common endodontic irrigants against Enterococcus faecalis biofilms.
• To compare the efficacy of sodium hypochlorite (NaOCl), chlorhexidine (CHX), EDTA, and acids at different exposure times.

Main Methods:

• Enterococcus faecalis biofilms were cultivated for 24 hours in an MBEC high-throughput device.
• Biofilms were exposed to serial dilutions of NaOCl, CHX, EDTA, citric acid, and phosphoric acid for 1, 5, and 10 minutes.
• Logarithmic reduction in viable cell counts determined the MBEC, defined as a ≥5 log unit reduction.

Main Results:

• Sodium hypochlorite demonstrated potent efficacy, eradicating biofilms at 0.00625% after 1 minute.
• Chlorhexidine required 5 minutes at 2% to achieve biofilm eradication.
• EDTA, citric acid, and phosphoric acid showed no significant efficacy in eradicating the biofilms under the tested conditions.

Conclusions:

• Sodium hypochlorite is the most effective irrigant for eradicating Enterococcus faecalis biofilms among the agents tested.
• Chlorhexidine shows moderate efficacy, while EDTA and acidic solutions are ineffective against these biofilms.
• Optimizing irrigant selection and application time is critical for managing endodontic biofilm infections.