The effect of silver and zinc oxide nanoparticle additionof acrylic resin on surface roughness, color and antifungal properties

The aim of this study to evaluate the effect of silver and zinc oxide nanoparticle addition to acrylic resin at different concentrations (1%, 2%, 5%, 10% of the liquid) on colour change, surface roughness and C.albicans adhesion. Nine different groups were prepared depending on the nanoparticle type and concentration. Silver (Ag) and zinc oxide (ZnO) nanoparticles were added to the heat- polymerized acrylic resin liquid at the rates of 1%, 2%, 5% and 10%. The disk-shaped samples with a thickness of 10x2 mm were fabricated. Color of the samples was measured with a colorimeter (Chroma Meter CR-400, Konica Minolta, Japan). The samples were subjected to thermal aging to simulate a 1-year clinical application. Color measurements of the samples were repeated after aging. Color change (ΔE00) was calculated using the CIEDE 2000 formula. Surface roughness measurements of the samples were performed with a contact profilometer (Mahr, MarSurf M 300C). Colony Forming Unit (CFU/ml) counts were conducted for the C.albicans adhesion test. AFM analysis was performed to analyze the surface topography and SEM analysis was performed to observe the cell structures of C.albicans. As a result of the study, no significant difference was found between the groups in surface roughness and CFU count values. No significant effect of Ag and ZnO nanoparticles on C.albicans adhesion was observed. It was observed that nanoparticle type and concentration affected the color change of acrylic resin. The addition of 1% ZnO nanoparticles to acrylic resin showed a color change below the perceptible threshold value (ΔE00<1.30). The addition of 2%, 5% and 10% ZnO and 1% and 2% Ag nanoparticle showed a color change below clinically acceptable threshold value (ΔE00<2.25). The addition of 5% and 10% Ag nanoparticles caused the color of the acrylic resin to change above the clinically acceptable threshold. While no significantly different color change was observed in the groups containing 1% Ag and ZnO nanoparticles after thermal aging compared to the control group, it was observed that the addition of 2% or more Ag nanoparticles caused a color change in the acrylic resin above the clinically acceptable threshold value compared to the control group. Further studies may focus on clinical studies using different nanoparticles at different concentrations. Key words: Denture stomatitis, Acrylic resin, Nanoparticle