Nonanoic acid-containing polymethyl methacrylate denture base inhibits Candida albicans growth and biofilm formation

OBJECTIVE: To evaluate the potential of incorporating the fatty acid, nonanoic acid (NA), as an antifungal agent into denture base material to prevent C. albicans denture colonisation and denture stomatitis.

MATERIALS AND METHODS: Antifungal efficacy of NA against C. albicans was assessed by paper disc diffusion assay. NA was incorporated into polymethyl methacrylate (PMMA) denture base and its properties tested. Colonisation of C. albicans on PMMA discs containing NA at 0 to 5% was examined by electron microscopy and XTT assay to measure microbial viability. The antifungal activity NA-containing PMMA discs was assessed using an in vitro tissue-engineered oral mucosal model of denture stomatitis.

RESULTS: C. albicans growth was inhibited by NA in a dose-dependent manner in a disc diffusion assay. When incorporated into PMMA, NA decreased the surface roughness of acrylic discs while increasing their wettability. PMMA alone discs showed no antifungal activity, while PMMA-containing NA discs displayed significant dose-dependent C. albicans growth inhibition in disc diffusion assays (p<0.05) with more potency than conventional antifungals. Moreover, 5% PMMA-NA significantly (p<0.01) reduced the colonisation of C. albicans on acrylic disc surfaces, preventing yeast-hyphal transformation and biofilm formation in a tissue-engineered oral mucosal infection model.

CONCLUSION: These data provide evidence that NA incorporated into denture material prevents denture-related fungal colonisation and may be an alternative antifungal agent for the prevention of denture stomatitis.

CLINICAL SIGNIFICANCE: This is an important discovery with high translational potential, where nonanoic acid targeted both the C. albicans "reservoir" on the denture surface and prevented fungal invasion of oral tissues.