Effect of Protective Coating on Surface Properties and Candida albicans Adhesion to Denture Base Materials

Purpose: To evaluate the effect of protective coatings on the surface roughness, contact angle, and Candida albicans (C. albicans) adhesion to polymethyl methacrylate (PMMA) denture base materials. Material and Methods: A total of 560 rectangular heat- and autopolymerized acrylic resin specimens were fabricated and divided into 5 groups (n = 14/group) according to coating agent. Uncoated specimens were used as control. Coating materials were: nano-coat, Optiglaze, nano-silica, or cyanoacrylate. Surface roughness (R_a) was evaluated using a profilometer. Contact angle measurements were performed using the sessile drop method. C. albicans adhesion was evaluated using direct culture and slide count methods. ANOVA and Tukey's post hoc tests were used for data analysis (α = 0.05). Results: Nano-coat and Optiglaze coating of heat-polymerized acrylic significantly decreased R_a (p < 0.001). No significant effect was seen with nano-silica coating while R_a significantly increased with cyanoacrylate (p < 0.001). For autopolymerized acrylic, nano-coat, Optiglaze, and nano-silica coatings significantly decreased R_a in comparison to control group (p < 0.001) while no significant difference was seen between control and cyanoacrylate coating (p = 0.45). In comparison to control group, nano-coat, Optiglaze, and nano-silica coating for both denture base materials significantly decreased contact angle, and C. albicans adhesion (p < 0.001) while cyanoacrylate significantly increased C. albicans adhesion (p = 0.002) with no effect on contact angle for heat- (p = 1.00) and autopolymerized resins (p = 0.83). Conclusion: Coating of removable prosthesis with nano-coat, Optiglaze, or nano-silica is an effective method to reduce C. albicans adhesion.