Effectiveness of Disinfectant Liquid Soaps in the Reduction of Candida spp Present in Complete Dentures: A Crossover Randomized Clinical Trial.

Abstract

To evaluate the effectiveness of liquid disinfectant soaps for the reduction of microorganisms present on maxillary complete dentures. The selected patients (N = 28) were randomly divided into four groups (n = 7), and each group underwent all four disinfection treatments in a different order. The disinfection treatments evaluated were: 0.5% sodium hypochlorite (positive control); Dettol liquid soap; Lifebuoy liquid soap; and phosphate-buffered saline solution (negative control). The patients were instructed to immerse their maxillary dentures in the disinfectant solution for 8 hours (overnight) for 7 days, with the solutions in a randomized sequence with a washout period of 1 week between solutions. Biofilm samples of the dental prostheses were obtained before and after each treatment with a sterile swab, and the microbiologic material was diluted and plated in selective media for Candida spp. Colony-forming unit count (CFU/mL) was performed in each group. One-way ANOVA with Welch correction was used for analysis, with Games-Howell post hoc test with a significance level of .05. A 3-log reduction in microorganisms was considered effective compared to baseline. The highest incidence observed was for Candida albicans, which presented with a frequency between 66% and 92%, followed by C tropicalis, with a frequency between 7% and 33%, in all experimental groups. Sodium hypochlorite was able to reduce more than 3 log10 of microorganisms for all patients, showing high antifungal effectiveness for both C albicans and C tropicalis species. Regarding the experimental groups, both liquid soaps (Dettol and Lifebuoy) were effective in reducing the two types of microorganisms. Liquid soaps were effective at reducing biofilm and may be an alternative for disinfection of removable partial dentures or complete dentures.