The aim of this study was to evaluate the effect of different pH of calcium hydroxide in killing Enterococcus faecalis. Materials and Methods: The bacterial sample of Enterococcus faecalis was collected preserved by lyophilization in an ampoule. Samples of calcium hydroxide with different pH (9.5, 10.5, 11.5, and 12.5) were prepared by dissolving calcium hydroxide powder in distilled water at room temperature. Bacterial colonies grown on blood agar plate were transferred to Trypticase soya broth and incubated. Sterilized paper points were transferred to vials containing 1ml test solutions and incubated at 37° c for 6, 24, 48 and 72 hours. Suspension of the microorganisms obtained then plated on to the blood agar plates and incubated. The number of colony forming units was calculated using the colony counter. Results: Inhibitory effects of different pH groups was as follows: GROUPV >GROUPIV > GROUP III > GROUP II > GROUP I in an ascending order. Conclusion: The ability of aqueous Ca (OH)2 solution in killing the bacteria increased with subsequent increase in pH of the solution.
Calcium hydroxide, Enterococcus faecalis, Blood agar, Trypticase soya broth
