Antimicrobial effect of two endodontic medicaments with different exposure times, and the morphologic alterations caused to Enterococcus faecalis

purpose: the aim of this study was to verify the antimicrobial effect of calcium hydroxide and iodoform on enterococcus faecalis with different exposure times evaluating the bacterial morphologic alterations. methods: the antibacterial action was investigated in culture broth after zero, seven, fourteen and twenty-one days. five ml samples were analyzed morphologically on the seventh day by transmission electron microscopy. the data of the antibacterial test were analyzed by fisher's exact test. results: the results revealed that between the seventh and fourteenth day, there was a decrease in bacterial growth with both medicaments (p=0.098), where they were eliminated between the fourteenth and twenty-first day. transmission electronic microscopy showed alterations in the morphologic structures. conclusion: it concluded that both medicaments kill enterococcus faecalis, with an exposure time of 7 to 14 days, where no cell viability is seen after this period due to irreversible alterations in bacterial cell morphology.