bacterial leakage in root canals fi lled with resin-based and mineral trioxide aggregate-based sealers

background: sealing ability is one of the most important features of endodontic sealers. the purpose of this in vitro study was to compare the sealing ability of a resin-based sealer with a mineral trioxide aggregate-based sealer. materials and methods: a total of 60 single-rooted extracted human teeth were randomly divided into two experimental groups (n = 25) and two control groups (n = 5). after canal preparation and smear layer removal, both groups were obturated with gutta-percha and sealer. resin-based ah26 sealer was used in the fi rst group and fillapex® sealer in the second group. two layers of nail varnish were applied on tooth surfaces except for the apical 2 mm. in the negative control group, nail varnish was applied on the entire surface. the teeth were mounted according to lima et al. study and then sterilized by ethylene oxide gas. the samples were evaluated for bacterial microleakage using enterococcus faecalis (atcc 29212) for 90 days. data were analyzed by survival test (p < 0.05). results: control groups had either immediate leakage or no leakage. the fillapex® showed signifi cantly higher amounts of microleakage compared with ah26 sealer (p < 0.05) and both groups exhibited signifi cant differences in comparison with control groups. conclusion: both sealers had bacterial leakage. sealing ability of ah26 was signifi cantly higher than that of fillapex®. key words: bacterial leakage‚ mineral trioxide aggregate-based sealer‚ resin-based sealer‚ root canal therapy