摘要Objective:To investigate the inhibitory effect of calcium hydroxide on methicillin-resistant Staphylococcus aureus and the related inhibition mechanism. Methods: To determine the minimum inhibitory concentration of calcium hydroxide using microplate dilution method; to compare the effects of calcium hydroxide at 8MIC, MIC, 1/4MIC and 0 concentrations on MRSA using growth curve method; to determine the effects of calcium hydroxide on the cell membrane of methicillin-resistant Staphylococcus aureus using calcium xanthophyll and propidium iodide fluorescence staining The effect of calcium hydroxide on the morphology of methicillin-resistant Staphylococcus aureus was observed by scanning electron microscopy; the inhibition mechanism of calcium hydroxide on MRSA was investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis of protein bands. Results: The MIC of calcium hydroxide on MRSA was 3.125 mg/mL; the fluorescence intensity showed significant changes after co-culture of calcium hydroxide with bacteria; MRSA appeared to be significantly crumpled and broken in the presence of calcium hydroxide; the SDS-PAGE experimental bands indicated that the protein inside the bacteria decreased accordingly with the increase of calcium hydroxide concentration. Conclusion: Calcium hydroxide has a significant inhibitory effect on the growth of MRSA, and its bactericidal mechanism may be related to the destruction of bacterial body structure.