Antimicrobial effect of propolis and other substances against selected endodontic pathogens.

Objective: The aim of this study was to determine the antimicrobial effect of ethanol extract of propolis (EEP) and intracanal medicaments calcium hydroxide, camphorated paramonochlorophenol, and formocresol by means of the macrodilution method using the reinforced clostridial medium (RCM) and brucella and brain heart infusion media.

Study Design: The antimicrobial agents were sequentially diluted and tested against anaerobic bacteria Prevotella nigrescens, Fusobacterium nucleatum, Actinomyces israelii, and Clostridium perfringens and against Enterococcus faecalis, with the 5 x 10(5) CFU/mL standardized inocula. The tubes were anaerobically incubated and the minimum inhibitory concentration was detected. Blood agar RCM subcultures were performed to provide minimum bactericidal concentration. The results were analyzed by analysis of variance test.

Results: All drugs were effective against all tested strains, without statistical differences. E. faecalis was the less susceptible strain, and RCM broth promoted faster bacterial growth, but there were no significant differences in these results. Ethanol did not influence the antimicrobial effect of EEP.