Abstract: Objective: To investigate the antibacterial effects of ozonated water at varying concentrations and exposure durations against major cariogenic pathogens. Methods: The optimal antibacterial concentration of ozonated water against Streptococcus mutans (S. mutans), Lactobacillus, and Actinomyces viscosus (A. viscosus) was determined. The same concentration was then applied for different durations to identify the optimal exposure time. Changes in pH and biofilm formation capacity were measured as outcome indicators to evaluate the inhibitory effects of ozonated water on bacterial proliferation. Saliva collected from healthy adults was used to simulate the oral environment and assess its influence on the antibacterial efficacy of ozonated water. Results: The optimal antibacterial concentration for all three cariogenic strains was 3.2 ppm. The most effective exposure durations were 60 seconds for S. mutans, 120 seconds for Lactobacillus, and 60 seconds for A. viscosus. Ozonated water reduced acid production by 15.1% and inhibited biofilm formation in all tested strains. However, when mixed with saliva, its antibacterial efficacy decreased to 65.2%. Conclusion: Ozonated water exhibits potent antibacterial effects at safe concentrations, demonstrating promising potential as a novel strategy for caries prevention and treatment.

Key words: ozonated water, Streptococcus mutans, cariogenic bacteria, antibacterial effect, Acvtinomyces viscosus, saliva, biofilms, dental caries