Abstract
Purpose To evaluate the effect of the addition of low concentration of silicon-dioxide nanoparticles (nano-SiO2) to poly(methylmethacrylate) (PMMA) denture base material onCandida albicansadhesion, surface roughness, contact angle, hardness, and translucency. Materials and methods A total of 150 acrylic disks were fabricated from heat-polymerized acrylic resin and specimens were divided into 3 groups of 50 per test. They were further subdivided into 5 subgroups (n = 10) according to the concentration of nano-SiO2: control (no addition) and four tested groups modified with 0.05, 0.25, 0.5, and 1.0 wt% nano-SiO(2)of acrylic powder. Slide count and direct culture methods were used to measureC. albicanscount (CFU/mL). The surface roughness values (R-a; mu m) were determined using a profilometer. The contact angle ((o)) measurement was performed by a goniometer using the sessile drop method. Vickers hardness was used to analyze surface hardness. Translucency was measured using a spectrophotometer. Data analysis was conducted through analysis of variance and Tukey's post hoc tests (alpha = 0.05). Results Compared to the control group, direct culture and slide count methods illustrated a significant decrease inC. albicanscount (p< 0.001) with the addition of nano-SiO2, and this decrease was correlated with the concentration of nano-SiO2. The addition of nano-SiO(2)significantly decreased the contact angle (p< 0.001), whereas hardness and surface roughness significantly increased (p< 0.001). The addition of nano-SiO(2)significantly decreased translucency (p< 0.001), and this decrease was concentration dependent. Conclusion Addition of low concentration of nano-SiO(2)decreasedC. albicansadhesion to PMMA denture base resin. Also, low additions of nano-SiO(2)have positive effects on contact angle and hardness, whereas surface roughness and translucency were adversely affected at high concentrations.