Analysis of Demineralized Chemical Substances for Disinfecting Gutta-percha Cones

INTRODUCTION: The aim of the present research was to evaluate the effectiveness of 5% malic acid, 17% EDTA and 10% citric acid solutions used to disinfect gutta-percha cones contaminated by Enterococcus faecalis (ATCC 29212). METHODS AND MATERIALS: Two hundred and ten previously sterilized gutta-percha cones were contaminated with E. faecalis at concentration of 1.5×10(8 )CFU/mL. The cones were immersed in 5% malic acid, 17% EDTA, 10% citric acid, 1% NaOCl and 2.5% NaOCl for 1, 5 and 10 min. Then each cone was kept in Eppendorf tubes containing BHI sterile solution at 37(°)C for 48 h. The presence of turbidity in BHI solution was analyzed. The results were statistically analyzed by Kruskal-Wallis test and 5% Dunn comparisons. P-value was considered statistically significant when P<0.05. RESULTS: Regardless of exposure time, 1% NaOCl and 2.5% NaOCl were the most effective agents for rapid disinfection of gutta-percha cones (P<0.001). All specimens immersed in experimental demineralized solutions presented bacterial growth (P>0.05). CONCLUSION: Demineralized solutions tested were not effective for elimination of Enterococcus faecalis on the surface of gutta-percha cones.