Leilasadat Tabatabaee - Postgraduate Student, Department of Pediatric Dentistry, Student Research Committee, Faculty of Dentistry, Khorasgan Azad University Branch, Isfahan, Iran
Masoud Saatchi - Associate Professor, Department of Endodontics, Torabinejad Dental Research Center, Faculty of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran
Rahman Nazeri - Student of dentistry, Isfahan University of medical sciences, Isfahan, Iran.
Hamid Razavian - Assistant Professor, Department of Endodontics, Torabinejad Dental Research Center, Faculty of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran

Introduction: MTA is a multi-purpose material in endodontics. Antimicrobial effect is one of the ideal properties of a root-end filing material. IKI (iodine potassium iodide( is a potent antimicrobial agent with low cytotoxicity. The purpose of this study was to assess the antimicrobial activity of MTA mixed with 1% IKI, 2% IKI and 4% IKI by direct and indirect methods.Methods:In this experimental study, direct contact test(DCT) was used to evaluate the antimicrobial activity of MTA mixed with different concentrations of IKI and distilled water against Enterococcus faecalis, Staphylococcus aureus and Candida albicans after setting at 0.5, 1 and 24-hour intervals. Colony Forming Units (CFU/mL) were determined. The agar Diffusion Test(ADT) was used to assess antimicrobial activity of fresh MTA mixed with 1%, 2% and 4% IKI and distilled water against E.faecalis, S.aureus and C.albicans. The diameter of the zone of inhibition was measured by calipers. Data were analyzed with SPSS 17 using ANOVA and Kruskal-Wallis, Mann-Whitney and Tukey tests (α=0.05).Results: DCT method showed that the antimicrobial activity of MTA mixed with 2% IKI and 4% IKI against E.faecalis, S.aureus and C.albicans at 24-hour interval was significantly higher than other concentrations(P=0.021). Antimicrobial activity of MTA mixed with 1% IKI was the same as MTA mixed with distilled water, with no significant difference (P=0.951). In the ADT method, the antimicrobial effect of MTA mixed with 4% IKI against C.albicans and S.aureus was significantly higher than other concentrations(P=0.042). Various concentrations of IKI mixed with MTA, compared to distilled water, did not exhibit significant antimicrobial properties against E.faecalis(P=0.864).Conclusions: 1% IKI and 4% IKI in DCT method and 4% IKI in ADT method exhibited higher antimicrobial activities than other concentrations.

Mineral trioxide aggregate, iodine potassium iodide, antimicrobial, colony forming unit, zone of inhibition