Antimicrobial Activity of Poly(methyl methacrylate) Doped with CuO and ZnO Nanoparticles

Oral health represents a significant factor in general health and life quality. A significant number of people are affected by tooth loss during their lifetimes, especially in the older population. Poly(methyl methacrylate) (PMMA) resins are the preferred option for replacing missing teeth due to the material stability, easy handling, low toxicity, and most importantly biocompatibility with human tissue. Even though PMMA is the preferable material for denture preparation, it is susceptible to microbial colonization, which can induce the development of oral infections. This study aimed to increase the antimicrobial effect of PMMA and compare the antimicrobial properties of PMMA incorporated with different amounts (2 and 5 wt %) of zinc oxide (ZnO; primary size 62.4 nm ± 16.7 nm) and copper oxide (CuO; primary size 434.0 nm ± 118.5 nm) nanoparticles to determine their antimicrobial effects on Gram-positive bacteria <i>Staphylococcus aureus</i> and yeast <i>Candida albicans</i>-pathogenic microbes often found on dentures. To understand the adhesion of microorganisms to PMMA-modified surfaces, the following surface properties were measured: roughness, contact angle, and ζ potential. In addition, CIE (the International Commission on Illumination) color parameters of the materials were determined. The bacterial adhesion was measured by viable plate counts and scanning electron microscopy. Our study showed that 5 wt % ZnO added to PMMA yields a promising denture material that is esthetically acceptable and shows antimicrobial properties toward both, <i>Staphylococcus aureus</i> and <i>Candida albicans</i>.