University of Kashan Journal of Nanostructures 2251-7871 15 3 2025 07 01 Antibacterial Effects of ZnO Nanoparticles and Capsicum Annuum Extract on Staphylococcus Mutans and Staphylococcus Aureus Isolated from Dental Cavities 1109 1114 114938 10.22052/JNS.2025.03.028 EN Wasan Mohammed Mousa Alsewidi College of Pharmacy, Mustansiriyah University, Baghdad, Iraq Ibrahim Hamad Alfahdawi College of Dentistry, University of Al-Maraif, Al-Anbar, Iraq Journal Article 2025 04 28 The purpose of this study is to determine the antibacterial effects of different concentrations of zinc oxide (ZnO) nanoparticles and extract from Capsicum annuum L. (pepper fruit) on Staphylococcus mutans (S. mutans) and Staphylococcus aureus (S. aureus) isolates that were obtained from dental caries. ZnO nanoparticles were achieved with a size range of 10–30 nm and a purity level of 99.8 %, and pepper fruit extracts were made using the Soxhlet extraction method. Several different concentrations were used in the agar well diffusion method to evaluate the effectiveness of antibacterial agents. According to the findings, ZnO nanoparticles exhibited inhibitory zones ranging from 2.11 to 2.97 mm for S. mutans and 2.01 to 2.66 mm for S. aureus, with 1.0 mg/mL for the maximum activity. The antibacterial activity of products increased with increasing concentration of the extract, reaching its maximum inhibition at 300 mg/mL. The combination of ZnO nanoparticles and extract from Capsicum annuum demonstrated dose-dependent antibacterial activity, indicating that these substances can be used in therapeutic applications against oral infections. https://jns.kashanu.ac.ir/article_114938_f63a6f09ab01a4a4436764b0032ad361.pdf