Objectives. To evaluate the antibacterial activity of four endodontic sealers: one epoxy resin seater (AH Plus), two zinc oxide eugenol (ZOE)-based sealers (Endomethasone, Pulp Canal Seater), and one seater containing both ZOE and orthophenilphenol (Vcanalare). Methods. A direct contact test (DCT) was performed. A 10 mu l suspension of Enterococcus faecalis was placed on the test material 20 min, 24 h and 7 days after mixing. Bacteria were allowed to directly contact the sealers for I h at 37 degrees C. Bacterial growth was then spectrophotometricatty measured every 30 min for 7 h, and again after 24 h as well. Results. All freshly mixed sealers showed complete inhibition of bacterial growth. Similar results were obtained with the 24-h-old samples, with the exception of AH Plus. Vcanalare was the only seater still inhibiting bacterial growth 7 days after mixing. Conclusions. The antimicrobial activity of the tested sealers depends on the time interval between mixing and testing. ALL sealers exhibit bactericidal effect when freshly mixed, but only Vcanalare extended this effect until 7 days after setting. (c) 2005 Elsevier Ltd. All rights reserved.