Antimicrobial Efficacy of Several Concentrations of NaOCl, CHX and EDTA in Fusobacterium Nucleatum, Porphyromonas Endodontalis, Enterococcus Faecalis.

Objectives: To evaluate the antimicrobial efficacy of the most commonly used concentrations of Sodium hypochlorite (0.5%, 1%, 2.5%, 5.25%), Chlorhexidine (0.05%, 0.12%, 2%) and EDTA (10%, 15%, 17%, 18%), against Fusobacterium nucleatum, Porphyromonas endodontalis, Enterococcus faecalis and combined.
Methods: The bacterial suspensions (1.5 x 10⁸ CFU/mL) were seeded in Tripticase Soy Agar, disk of sterile paper impregnated with the different concentrations of irrigant solutions were placed and incubated in an anaerobic environment per 24 h to observe the inhibition areas.
Results: The average of the inhibition areas of growth for NaOCl, CHX and EDTA were, respectively: 1.2, 1.7, 1.5, 2.4, 1, 1.3, 2.3, 1.6, 1.7, 1.9, 2 (F.nucleatum), 1.4, 1.7, 2.4, 3.3, 1.9, 2.2, 2.7, 2.3, 2,6, 2.8, 2.9 (E. faecalis) 1.4, 1.4, 1.4, 1.4, 1.5, 1.7, 2,4, 1.3, 1.4, 1.8, 1.8 (P. endodontalis).
Conclusions: The best results against F. nucleatum were with NaOCl at 5.25% and CHX at 2%, against E.Faecalis with NaOCl at 5.25% , the effect of CHX and EDTA were similar, against P. endodontalis was with CHX at 2%. It is important to mention that EDTA at 17% and 18% obtained better results than NaOCl at 5.25%.