In Vitro Assessment of Artificial Aging on the Antifungal Activity of PMMA Denture Base Material Modified with ZrO(2) Nanoparticles

The antifungal effect of zirconium dioxide nanoparticles (ZrO(2)NPs) incorporated into denture base material has been inadequately investigated; additionally, to the authors' knowledge, no studies have assessed the influence of artificial aging on the antifungal activity of these particles. Methodology. Heat-polymerized acrylic resin disks were fabricated and divided into four groups (0%, 1%, 2.5%, and 5% ZrO(2)NPs by weight). Antifungal activity was assessed using the direct culture and disk diffusion methods. Surface roughness and contact angles were measured using a profilometer and a goniometer, respectively. The artificial aging procedure was performed by repeating all tests at 7, 14, and 30 days following 2 rounds of thermocycling. Data were analyzed using ANOVA and Tukey's post-hoc test (p < 0.05). Results. The addition of ZrO(2)NPs significantly decreased the adhesion of Candida albicans with and without artificial aging procedures (p < 0.001), while the disk diffusion methods did not reveal inhibition zones. ZrO(2)NP-modified specimens displayed significantly higher surface roughness compared to specimens in the control group (p < 0.05) and showed the same behaviors with artificial aging procedures. The contact angle was significantly decreased in all modified groups in comparison to the control group (p < 0.05). Conclusion. The addition of ZrO(2)NPs to polymethylmethacrylate denture base material reduced the adhesion of Candida albicans with a long-term antifungal effect. With the addition of ZrO(2)NPs, contact angles were decreased and surface roughness was increased; 1% was the most appropriate concentration. Clinical significance. The addition of ZrO(2)NPs to denture base material confers a long-term antifungal effect and could be used as a possible method for preventing and treating denture stomatitis.