Aim: this study aimed to compare a modified calcium silicate resin- based sealer (MTA Fillapex) with a standard resinous sealer (AH Plus) regarding ; Biocompatibility in experimental animals and Inhibitory effect of the tested materials on E. feacalis using the agar diffusion test and the direct contact test. Method: For the biocompatibility evaluation, polyethylene tubes containing the tested materials were implanted in 15 rats. After 3, 7, and 30 days, tissues were collected for biopsy and processed for histologic evaluation. Observations were made of the cellular inflammatory reaction, the fibrous capsule and necrosis. Comparisons between groups were made with the Kruskall-Wallis and the Chi-square (x2) tests. For the agar diffusion test (ADT), the freshly mixed sealers were placed in the prepared wells of agar plates inoculated with the test microorganism. The plates were incubated for 24, 48 and 7 days. The mean zones of inhibition were measured after each incubation time. In the direct contact test (DCT), the sealers were mixed and placed on the side wall of microtitre plate wells. A 10 μL suspension of Enterococcus faecalis was added to the surface of the sealers 1 h, 48 h, or 7 days after mixture. Bacteria were allowed to come into contact with the sealers for 1 h at 37°C. Fresh media was then added and bacterial growth was measured. ANOVA test was used to compare between the groups. Tukey’s post-hoc test was used for pair-wise comparisons between the groups when ANOVA test was significant. Result and Conclusion: MTA Fillapex is better tolerated by the tissues at an experimental period of 30 – days than at 3 and 7 days. Despite, The tissue tolerance to the AH Plus at an experimental period of 30 –days is not greatly different from that at 3 and 7 days. MTA Fillapex and AH plus possess an inhibitory effect on the growth of Enterococcus faecalis in the fresh state, MTA Fillapex sustains this effect for two days after mixing but None of the two sealers sustains the antibacterial effect for seven days after mixing.