Abstract: Objective To study oxidative stress antibacterial mechanism of rare earth nanomaterial Ce/Ag/ZnO against oral Saccharomyces albicans. Methods Bacterial plate culture, bacterial growth curve drawing and scanning electron microscopy (SEM) and oxidative stress related biochemical indexes detection and other experimental methods were adopted. Results The MIC and MBC of Ce/Ag/ZnO on Saccharomyces albicans were 0.156 mg/mL and 0.313 mg/mL, respectively. SEM showed that the bacteria crumpled and collapsed; the contents leaked; the cell membrane was seriously damaged. The level of reactive oxygen species (ROS), the degree of lipid peroxidation (LPO) and the activity value of catalase (CAT) of bacteria were significantly increased (P＜0.05). Conclusion This experiment proves that nanomaterials modified by rare earth still have good antibacterial effect, and reveals their antibacterial mechanism of inducing oxidative stress reaction inside saccharomyces albicans. This provides theoretical support for the application of this material in the manufacture of denture base and for the prevention of denture stomatitis in the future.

Key words: rare earth nanomaterials Ce/Ag/ZnO, saccharomyces albicans, oxidative stress, antibacterial mechanism