Optimized synthesis of novel hydroxyapatite/CuO/TiO2 nanocomposite with high antibacterial activity against oral pathogen Streptococcus mutans

Abstract The main issue of using hydroxyapatite (HA) in dentistry is accumulation of microorganisms on it that causes tooth decay. The use of nanoparticles can decrease the accumulation of microorganisms, including Streptococcus mutans on HA, and increase its antibacterial effect. The present study aimed to determine the optimal conditions to synthesize HA/CuO/TiO2 nanocomposites with the highest antibacterial properties. Utilizing the Taguchi method, nine experiments were designed to fabricate nanocomposites using 3 factors of hydroxyapatite, CuO and TiO2 nanoparticles. The antibacterial activity of the synthesized nanocomposites was evaluated by the colony forming units (CFU) method against S. mutans. Nanocomposite synthesized under experimental conditions 2 (hydroxyapatite 20 mg/ml, CuO 1.50 mg/ml and TiO2 1.60 mg/ml) had the highest effect on reducing the growth of S. mutans (1.24 CFU/ml). The results demonstrated the improvement of structural properties, antibacterial activity, and thermal stability by formation of nanocomposite. Owing to the desirable antibacterial properties of the HA/CuO/TiO2 nanocomposite, it can be used to improve performance in various dental fields.