Demetallization of Enterococcus faecalis biofilm: a preliminary study

Area of Science:

• Dental Research
• Biofilm Management
• Biochemistry

Background:

• Enterococcus faecalis is a common pathogen in persistent root canal infections.
• Biofilm formation by E. faecalis complicates root canal disinfection.
• Chelating agents are used to remove inorganic debris and biofilm components.

Purpose of the Study:

• To investigate the effect of pH on chelator efficacy in removing specific ions from E. faecalis biofilms.
• To quantify calcium, iron, manganese, and zinc ion concentrations after irrigation protocols.

Main Methods:

• Bovine incisors were inoculated with E. faecalis to form biofilms over 60 days.
• Irrigation solutions included 17% EDTA (pH 3, 7, 10), 2.5% NaOCl, and combinations, with distilled water as control.
• Ion concentrations were measured using flame atomic absorption spectrometry.

Main Results:

• Calcium chelation was highest with 17% EDTA at pH 7.
• Iron concentration peaked at pH 3 with 17% EDTA in the presence of biofilm.
• Manganese levels were highest with 2.5% NaOCl and 17% EDTA (pH 7) in biofilm.
• Zinc ions were not detected.

Conclusions:

• The pH of chelating agents critically influences the removal of calcium, iron, and manganese ions.
• 17% EDTA at pH 3 resulted in higher iron ion concentrations in root canals with E. faecalis biofilm compared to other tested solutions.