 Calcium hydroxide has been found to have antibacterial properties against certain strains of bacteria, including E. ficalis, S. mutants, S. sanguines, and P. gingivalis. These bacteria are commonly associated with chronic periapical abscesses, which can be treated with intracanal medications containing calcium hydroxide. In this study, it was determined at the lowest minimum inhibitory concentrations, mic, and minimum bactericidal concentrations, M. b. c., were achieved when calcium hydroxide was applied to these bacteria within the first week of incubation. This suggests that calcium hydroxide may be effective in treating chronic periapical abscesses caused by these bacteria. This article was authored by Cheney Moni Dwiayuputri, Diani Prezinda, and Yudi Melinda.