In vitro comparison of the effects of microwave irradiation and chemical and mechanical methods on the disinfection of complete dentures contaminated with Candida albicans

Dentures can be a source of infection or cross‑contamination with microorganisms like Candida albicans. The aim of this in vitro study was to compare the effects of microwave irradiation, chemical techniques, and a mechanical method (i.e., brushing) on the disinfection of complete dentures contaminated with C. albicans. In this experimental study, sixty sterilized dentures were divided into six groups of 10 dentures each. The dentures in Groups 1 and 6 served as negative and positive controls, respectively. The dentures (Groups 2–5) were contaminated with C. albicans and subjected to four disinfection procedures: Corega tablets, 2% glutaraldehyde, brushing, and microwave irradiation. Replicate aliquots (25 mL) of the suspension were cultured in Sabouraud dextrose broth. The colonies were counted after 48 h of incubation at 37°C. To confirm long‑term disinfection, the Trypticase soy broth (TSB) containers were stored at 37°C for 7 days, and turbidity was visually observed. Data were analyzed with one‑way ANOVA and independent‑samples t‑test on SPSS the level of statistical significance was set at 0.05. The dentures disinfected with microwave irradiation (650 W, 3 min) and glutaraldehyde (2%, 10 min) exhibited no evidence of fungal growth after 48 h of incubation and also no turbidity in the TSB containers after 7 days of incubation. However, the dentures disinfected using the mechanical method and Corega tablets exhibited turbidity after 7 days and fungal growth after 48 h that was significantly more than that in the two other methods (P = 0.000) and less than that in the positive control group (P = 0.000). The differences between mechanical cleaning and cleansing tablet were not significant (P = 0.017). Base on the results of this study, microwave irradiation (650 W, 3 min) and 2% glutaraldehyde completely disinfected the dentures contaminated with C. albicans in the short term and long term.