Characterization, antimicrobial activity, biocompatibility, and inflammatory response of 3D-printed denture base...

We functionalized a three-dimensionally (3D) printed denture base resin with α-Ag₂WO₄ microcrystals and evaluated its chemical and surface properties, flexural strength, antimicrobial activity, biocompatibility, and inflammatory response.

Resin specimens were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The surface roughness was evaluated by profilometry and wettability, whereas the surface free energy was determined using a goniometer. The flexural strength of the resin was assessed by three-point mechanical flexural testing. Antimicrobial activity was evaluated against Candida albicans, Staphylococcus aureus, and Escherichia coli in the adhesion and biofilm formation phases by counting colony-forming units (CFU)/mL and using confocal laser scanning microscopy (CLSM). Time-kill curve assays were performed using the Alamar Blue (AB) reagent, and the biocompatibility of the materials was evaluated in a 3D organotypic model of the oral mucosa using AB and CLSM. Inflammatory response was assessed by measuring cytokine production using flow cytometry.

XRD, FTIR, and SEM analyses demonstrated that α-Ag₂WO₄ was incorporated into the resin with its structure preserved. The surface roughness did not change, and the surface free energy increased; however, the flexural strength decreased slightly. The evaluated resins exhibited antifungal and antibacterial effects at both the adhesion and biofilm formation stages. Functionalization did not alter the biocompatibility of the resins and did not cause an exacerbated inflammatory response.

Functionalization of a 3D-printed denture base resin with α-Ag₂WO₄ demonstrated antimicrobial activity without any detrimental effects to the surface, mechanical, and biocompatibility properties of the material.