The antimicrobial activity of an experimental solution containing essential oil of Lippia sidoides for denture cleaning was evaluated by (1) minimum inhibitory (MIC) and fungicidal/bactericidal concentration (MFC/MBC) tests against Candida albicans, Staphylococcus aureus, and Pseudomona aeruginosa; (2) the metabolic activity of C. albicans biofilm formed on flat-bottom microplates and denture base specimens based on the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT); and (3) scanning electron microscopy, to evaluate the fungal biofilm morphology. The solution showed antimicrobial action against the pathogens tested (C. albicans - MIC and MFC: 19.53 µg ml-1, S. aureus - MIC and MBC: 78.12 µg ml-1, P. aeruginosa - MIC: 625 µg ml-1, MBC: 2,500 µg ml-1), reduced the metabolic activity of C. albicans biofilm up to 97%, and caused cell wall damage at low concentrations (195.3-390.6 µg ml-1) and in short time periods (20 min). Therefore, the experimental solution has the potential to be used as an alternative in the prevention and treatment of denture-induced infections.
Keywords: Biofilm; Candida albicans; Lippia; denture cleansers; denture stomatitis.