Abstract Curcuma longa is a popular plant around the world with various applications in food and medicinal aspects. An investigation has been conducted on the formulation of Ag/Cu nanocomposite by C. longa as a natural stabilizing agent, without the use of any toxic or harmful reagents. This bio-inspired approach is focused on applicative, facile, and green chemical research. The study also explored the potential of Ag/Cu nanocomposite to prevent dental bacteria growth and prevent adherence in vitro. The biomediated Ag/Cu@ turmeric NCs were characterized by advanced physicochemical techniques. The FE-SEM imaging has established that Ag/Cu@ turmeric has a semi-spherical shape (60.92 nm). The crystallinity of nanocomposite has been confirmed by the XRD technique. Subsequently, the biological activity of the Ag/Cu nanocomposite functionalized with biomolecules was examined. The concentration of 1,000 µg/mL showed the most effective minimum inhibitory concentrations (MICs) against Porphyromonas gingivalis and Streptococcus mutans (MIC = 16 µg/mL) during the investigation. The addition of Ag/Cu nanocomposite (MIC = 32 µg/mL) significantly hindered the S. mutans in vitro adherence. According to the findings of this research, Ag/Cu nanocomposite could potentially serve as an effective oral hygiene agent for managing periodontopathic and dental caries conditions.