Effectiveness of chlorhexidine on the disinfection of complete dentures colonised with fluconazole‐resistant Candida albicans : in vitro study

Summary This in vitro study evaluated different concentrations of chlorhexidine (CHX) solution on the disinfection of dentures colonised with a reference (ATCC 90028) and azole‐resistant (R1, R2 e R3) strains of Candida albicans . Sterile dentures were individually inoculated with one of the strains and incubated at 37 °C for 24 h. Then, each denture was immersed in sterile saline (control) or CHX (2%, 1% or 0.2%) for 10 min. Samples of serial dilutions were spread on Agar Sabouraud Dextrose and incubated at 37 °C for 48 h. The colonies were counted and the values of log(cfu ml −1 ) were analysed by Kruskal–Wallis test ( P  < 0.05). Dentures immersed in CHX were incubated for 7 days. For all strains, the cfu ml −1 values of 0.2% CHX were significantly higher than those of 2% and 1% CHX. There was no difference between the cfu ml −1 values of 2% and 1% CHX. For dentures immersed in CHX, ATCC 90028 strain showed lower cfu ml −1 values than R2 and R3 strains. For control dentures, cfu ml −1 values of ATCC 90028 strain were higher than those of R strains. Immersion in 2% CHX resulted in the highest number of dentures without fungal growth after 7 days. For denture disinfection, 2% CHX was the most effective concentration, and R strains were less susceptible to disinfection. Chlorhexidine is effective in disinfection of dentures contaminated with azole‐resistant C. albicans .