Confocal laser scanning microscopy shows the formation of MRSA biofilm on cement specimens. Cement without AuNPs (control), (A); Cement-AuNPs (0.25% w/w), (B); Cement-AuNPs (0.50% w/w), (C); Cement-AuNPs (1% w/w), (D). Biofilms were stained with live/dead BacLight viability stain (Life Technologies, Monza, Italy): SYTO9 (green) represents viable cells; propidium iodide (red) represents dead cells. Cement-AuNPs 1% by weight represents the most effective in reducing biofilm formation. In all images the scale bar = 30 μm.