Green Synthesis, Antimicrobial Efficiency, and Cytotoxic Effects of Silver–Zinc Oxide Nanocomposites: An In Vitro Study

with increasing interest in eco-friendly synthesis methods to ensure sustainable application in oral healthcare.[6][7][8][9][10] Incorporation of these nanoparticles into mouthwashes, toothpaste, and bioactive dental materials can provide sustained protection against cariogenic and periodontopathic microbes.Moreover, nanodelivery enables IntroductIonThe global increase in antibiotic-resistant pathogens has substantially undermined the effectiveness of conventional antimicrobial treatments in dentistry.Diseases such as dental caries, periodontitis, and endodontic infections continue to pose serious public health challenges, with microorganisms such as Streptococcus mutans, Enterococcus faecalis, Staphylococcus aureus, Lactobacillus acidophilus, and Candida albicans playing key roles.1,2 These microbes are capable of developing robust biofilms and demonstrating elevated resistance to commonly used antibiotics, highlighting the critical need for innovative antimicrobial strategies.Nanotechnology offers a promising solution, with metal-based nanoparticles demonstrating broad-spectrum antimicrobial activity.Among these, silver (Ag) and zinc oxide (ZnO) nanoparticles have been extensively studied for their potent bactericidal and fungicidal properties.Ag nanoparticles disrupt microbial cell membranes and interfere with DNA replication, while ZnO nanoparticles generate reactive oxygen species and release Zn 2+ ions, both of which contribute to microbial inactivation, and combining these two materials into an Ag-ZnO nanocomposite can yield synergistic effects, enhancing antimicrobial efficacy and reducing the likelihood of resistance development.[3][4][5] As resistance to conventional treatments grows, nanotechnology provides a promising alternative,