An in Vitro Evaluation of Antimicrobial Activity of Different Endodontic Sealers

Microbes are considered as the primary etiologic agents in endodontic diseases. The ways of reducing these agents are: root canal debridement, antimicrobial irrigants and antibacterial filling materials. But the complexity of the pulp canal system presents a problem for chemo mechanical preparation. One of the factors determining the success of endodontic treatment is the sealing material with a potent bactericidal effect. The aim of the present study was to assess the antimicrobial activity of endodontic sealers of different bases – in vitro. The antimicrobial activity of three root canal sealers (Endomethasone, AH 26 and Apexit) was evaluated against seven strains of bacteria at various time intervals using the agar diffusion test. The freshly mixed sealers were placed in prepared wells of agar plates inoculated with the test microorganisms. The plates were incubated for 24, 48, 72 hours and 7 and 15 days. The mean zones of inhibition were measured. All statistical analysis was performed using the SPSS 13 statistical software version. The analysis of variance (ANOVA), Post-hoc Bonferroni test and Paired “t” test were performed to know the effects of each variable and to reveal the statistical significance. All the data were presented in tabular and Bar diagram form. Zinc oxide eugenol based sealer (Endomethasone) exhibited the highest antibacterial activity at all time intervals followed by the Epoxy resin based sealer (AH 26) and least by the Calcium hydroxide based sealer (Apexit). Greatest antimicrobial efficacy for all the three sealers was seen at 24 hour time interval which kept on diminishing with time and reached to the lowest level at 7 day time interval. Results also showed that the zones of inhibition produced by each sealer decreased with time, and was the least after the seven days of incubation. The differences among all the groups were significant statistically (p<0.001) at all the four time intervals under study. Zinc oxide eugenol based root canal sealer produced largest inhibitory zones followed in decreasing order by Epoxy resin based sealer and least by Calcium hydroxide based root canal sealer. (J Int Dent Med Res 2010; 3: (3), pp. 108-115 )