Antibacterial and antifungal properties of compomer materials modified with silver nanoparticles and copper oxide, with determination of their cytotoxicity

Background.Tooth decay is a common problem, particularly among young patients.Compomer materials combine favorable aesthetic properties and durability with antibacterial activity resulting from fluoride release.The incorporation of silver (Ag 0 ) and copper oxide (CuO) particles may further enhance their antimicrobial properties, reducing the risk of complications such as secondary caries and pulpitis.Objectives.The aim of the study was to evaluate the cytotoxic and antibacterial properties of compomer materials doped with 0. 125 wt%, 0.25 wt% and 0.5 wt% CuO and Ag 0 particles using both static and dynamic methods in the Centers for Disease Control and Prevention (CDC) biofilm reactor.Material and methods.Reference microbial strains were stored at -80°C in tryptic soy broth (TSB) supplemented with 15 wt% glycerol and cultured under strain-specific conditions before the experiments.Streptococcus mutans, Lactobacillus rhamnosus, Candida albicans, and Staphylococcus epidermidis were grown on appropriate media under aerobic, anaerobic or elevated CO 2 conditions.Microbiological analysis involved preparing standardized microbial suspensions (0.5 McFarland), incubating them with the tested biomaterials under appropriate conditions.After incubation, biofilms were detached using saponin, serially diluted and plated on selective media, after which colony-forming units (CFU/mL and CFU/cm 2 ) were calculated.The experiments were performed in 6 replicates using both static and dynamic (flow reactor) biofilm models.Cytotoxicity was evaluated according to the ISO 10993 standard using L929 fibroblasts and BALB/3T3 cells exposed for 24 h to extracts or disks containing Ag 0 and CuO at concentrations of 0. 125 wt%, 0.25 wt% and 0.5 wt%.Results.Both Ag 0 and CuO exhibited statistically significant dose-dependent antibacterial activity against S. mutans and S. epidermidis.Silver nanoparticles at concentrations of 0.25 wt% and 0.5 wt% demonstrated the highest cytotoxicity in both BALB/3T3 and L929 cell lines.Conclusions.The incorporation of both CuO and Ag 0 particles into compomer materials enhanced their antimicrobial activity against S. mutans and S. epidermidis.