A method of making an antimicrobial poly(methyl methacrylate) (PMMA)/silver nanocomposite comprising PMMA and silver nanoparticles. The method includes reacting at least one silver salt with a methyl methacrylate (MMA) monomer in at least one organic solvent free of water and in the presence of at least one organic free radical initiator to polymerize the MMA monomer to form the PMMA by free radical polymerization while reducing in-situ the silver salt to form the silver nanoparticles, wherein the silver nanoparticles have an average particle size of 35-60 nm, and wherein the PMMA forms a matrix that encloses the silver nanoparticles.