Comparative in vitro antibacterial activity of six root canal sealers against Enterococcus faecalis and Proteus vulgaris

Aim: To evaluate the antimicrobial properties of six endodontic sealers in unset and set states against Enterococcus faecalis and Proteus vulgaris. Methods: Six endodontic sealers were investigated in the unset and set state against Enterococcus feacalis and Proteus vulgaris using agar diffusion and direct contact tests. Results: The mean inhibition zones for agar diffusion tests with Enterococcus feacalis were 19 mm for AH-26, 11 mm for TopSeal and Roth 601, 1 mm for AH-Plus, and 0 mm for GuttaFlow and EndoREZ (Kruskal-Wallis, P < 0.001). The mean inhibition zones with Proteus vulgaris were 24 mm for Roth 601, 19 mm for TopSeal, 17 mm for AH-Plus, 16 mm for AH-26, and 0 mm for GuttaFlow and EndoREZ (Kruskal-Wallis, P < 0.001). Direct contact tests showed inhibition of both Enterococcus feacalis and Proteus vulgaris with AH-Plus, TopSeal, Roth 601, and AH-26 in the unset state. Only Roth 601 in the set state affected both the log and the stationary phase of Proteus vulgaris (logistic regression P < 0.001). Conclusions: With the exception of Roth 601, which retained its antimicrobial activity, the AH-Plus, TopSeal, and AH-26 sealers all demonstrated antimicrobial properties against Enterococcus feacalis and Proteus vulgaris that diminished when set. TopSeal significantly affected Enterococcus feacalis when compared with AH-Plus. GuttaFlow and EndoREZ expressed no antimicrobial activity.