In vitro antimicrobial activity of maleic acid and ethylenediaminetetraacetic acid on endodontic pathogens

Objective. The aim of this study was to evaluate the antimicrobial efficacy of 7% maleic acid (MA) and 17% ethylenediaminetetraacetic acid (EDTA) in elimination of Enterococcus faecalis, Candida albicans, and Staphylococcus aureus at different time intervals. Study design. Transfer culture of microbial strains were used for inoculum preparation and determination of time-kill assay. The viability counts of 7% MA and 17% EDTA suspensions were performed at 0, 2, 4, 6, 12, and 24 hours. Assay results were analyzed by determining number of strains that yielded log(10) CFU/mL of -1 compared with counts at 0 hours, for test medicaments at time intervals. Medicaments were considered to be microbicidal at a minimum inhibitory concentration that reduced original inoculum by >3 log(10) CFU/mL (99.9%) and microbiostatic if inoculum was reduced by <3 log(10) CFU/mL. Statistical analysis was performed using chi-square and Fisher exact tests as well as Friedman test for comparison of the time interval within the MA and EDTA groups. Results. At all time intervals, there was no significant difference between MA and EDTA for all of the organisms (P > .05). However, within the MA and EDTA groups at various time intervals, there were significant differences (P > .001). Conclusions. Equivalent antimicrobial activity was observed by MA and EDTA against all of the organisms tested at various periods. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;112:696-700)