Polyetherketoneketone (PEKK) is an alternative material for use in removable partial denture frameworks; these frameworks must exhibit antibacterial properties to reduce the risk of periodontal disease. In the present study, silver nanoparticles (AgNPs) were synthesized via the reduction of silver nitrate with sodium borohydride in a solution containing polyvinyl pyrrolidone (PVP). Transmission electron microscope images and dynamic light scattering confirmed that metallic nanoparticles had been created with an average size of 32 nm. Furthermore, the coating of the PEKK polymeric substrate with 0.5% AgNPs was carried out using an epoxy resin lining at room temperature. Fourier transform infrared (FTIR) spectra confirmed the successful transfer of the AgNP-in-resin lining onto the polymeric substrate. Scanning electron microscopy and atomic force microscopy confirmed that the AgNPs had been uniformly deposited onto the PEKK specimens. Finally, the antibacterial activity of the specimens was tested against Porphyromonas gingivalis. An inhibition zone of 22.5 mm and an antibacterial rate of 83.47% were found for the PEKK coated with 0.5% AgNPs (0.5% Ag-PEKK) compared to an untreated polyetheretherketone (PEEK) substrate, evidencing that 0.5% Ag-PEKK has potential antibacterial properties for implant applications.