Effect of Chemical Disinfectants on Candida albicans Biofilm Formation on Poly (Methyl Methacrylate) Resin Surfaces: A Scanning Electron Microscope Study

Abstract

Objective: The purpose of this study was to understand the complexities of Candida albicans biofilm formation and to evaluate the effectiveness of most used antimicrobial agents. Materials and Methods: About 24 acrylic resin specimens (2 mm thickness, 10 mm diameter) were prepared. The contact angle and surface roughness of all specimens were measured. C. albicans ATCC10231 was incubated in Sabouraud dextrose agar (SDA) at 37°C for 24 h. Subsequently, SDA was incubated at 37°C for 48 h. Specimens were immersed to 1% and 2% sodium hypochlorite and phosphate-buffered saline for 10 min and 4% chlorhexidine gluconate for 5 min. The efficiency of chemical disinfectants in removing C. albicans biofilm was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide assay test. After application of chemical disinfectant, acrylic resin specimens were examined using scanning electron microscopy (SEM). The evaluation of the efficiency of chemical disinfectant was analyzed with one-way ANOVA and post-hoc Tukey test. Results: The highest and lowest efficiency to remove C. albicans biofilm was identified for 1% sodium hypochlorite and 4% chlorhexidine gluconate. The efficiency of 1% and 2% sodium hypochlorite solution to remove biofilm showed no statistical difference. SEM analysis indicated that after the application of 1% and 2% sodium hypochlorite no fungal cells were observed, and application of 4% chlorhexidine gluconate revealed a few remaining blastospores and hyphal cells attached to the resin surfaces. Conclusions: Disinfection with 1% and 2% sodium hypochlorite solutions revealed the most impressive results to reduce the C. albicans biofilm formation than 4% chlorhexidine gluconate solution.