Aim and Objectives: To evaluate the antimicrobial activity of three endodontic sealers AH Plus, Apexit plus and MTA Fillapex on three types of isolated root canal microorganisms: Enterococcus Faecalis, Staphylococcus Aureus and Candida Albicans using agar diffusion test.

Material and Method: Three endodontic sealers were evaluated in this study: AH Plus (Dentsply, Rio de Janeiro, RJ, Brasil), Apexit Plus (Vivadent; Schaan, Liechtenstein) and MTA Fillapex (Angelus, Londrina, PR, Brazil). The following reference strains were included in this study: Candida albicans, Enterococcus faecalis, and Staphylococcus aureus.

Antimicrobial activity of the materials was evaluated by the method of agar diffusion. A base layer of 10 ml of Mueller Hinton agar was poured in Petri plates (90 x 15 mm).

Inhibition halos formed around the wells were measured with the aid of a millimetric rule with 0.5 mm of accuracy. All the experiments were repeated three times in different moments.

Result: In inter group comparison, antimicrobial action of AH Plus was superior to that of Apexit Plus and MTA Fillapex against all the tested microorganisms p < 0.05). In intra group comparison AH Plus was significantly more effective against Candida, followed by Staphylococcus aureus and Enterococcus faecalis (p < 0.05)

Conclusion: AH Plus showed maximum antimicrobial activity followed by MTA Fillapex against all the tested microorganisms.