Abstract: Objective: To study the effect of Ag-embedded nano-TiO₂ (Ag - TiO₂) antibacterial agent on the antibacterial of alginate impression materials, to analyze the appropriate ratio of the antibacterial agent to the alginate impression material. Methods: The Ag-embedded nano-TiO₂ powder were added into the alginate impression materials according to different contents, including 0%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%,Their antibacterial activities were tested by film adhesion method. Results: Data showed the experimental group had statistically significant difference control group (all P<0.05). The difference increased with Ag-TiO₂ antibacterial agent added mass ratio. The antibacterial efficiency was beyond 99% when the adding ratio of antibacterial agent was 2.0% or beyond 20%. Conclusion: Adding Ag-TiO₂ antibacterial agent in alginate impression materials had antimicrobial potential, and the best adding ratio of the Ag-TiO₂ antibacterial agent was 2.0%.

Key words: Nano.Ag-TiO₂ antibacterial agent, Alginate impression materials, Candida albicans, The antibacterial rate