Antifungal Activities and Some Surface Characteristics of Denture Soft Liners Containing Silicon Dioxide Nanoparticles

OBJECTIVE: This study aimed at determining the influence of adding silicon dioxide nanoparticles (nano-SiO(2)) to soft relining materials on C. albicans adhesion, surface roughness, and contact angle. MATERIALS AND METHODS: Eighty heat-polymerized acrylic resin disks were constructed and relined by using auto-polymerized acrylic soft liners (COE-SOFT, GC Co., Tokyo, Japan). The specimens were categorized into two groups according to the tests conducted. Group A was composed of 40 specimens for evaluating antifungal activity, and Group B was composed of 40 specimens for testing surface roughness and contact angle. Each group was subcategorized into four subgroups (n = 10) according to the concentration of nano-SiO(2) added to the soft-liner powder: control, 0.25%, 0.5%, and 1.0% by weight. The colony forming unit (CFU) was used to assess C. albicans count. A profilometer was used to measure the surface roughness values (Ra; μm). The sessile drop method was used to evaluate the contact angle ((o)) by using a goniometer. Analysis of variance and Tukey’s post hoc tests (α = 0.05) were used for the data analysis. RESULTS: In comparison with the unmodified group, the 0.25% and the 0.5% nano-SiO(2) groups exhibited significantly lower C. albicans counts (P < 0.001), surface roughness (P < 0.001), and contact angles (P < 0.001). The exception was the 1% group, which exhibited higher C. albicans count, surface roughness, and contact angles than lower-concentration nano-SiO(2) groups; however, these values in the 1% group were still less than their respective values in the control group. CONCLUSION: The addition of 0.25% and 0.5% nano-SiO(2) to an auto-polymerized acrylic soft liner decreased C. albicans adhesion, surface roughness, and contact angle.