Growth of Candida Species on Commercial Denture Adhesives in Vitro

Purpose: Although denture adhesives are widely used by the elderly, it is unknown whether denture adhesives support microbial growth. Therefore, we investigated the growth of Candida species on six commercial denture adhesives. Materials and Methods: The growth of a single isolate of C albicans and C tropicalis on six commercial denture adhesives was investigated by monitoring pH changes in growth media. Results: In the preliminary study, the effect of each product on the pH value of the medium was examined; a single product itself significantly reduced the pH of medium below 5.0. When the yeast was grown on the materials, the pH changes in the media varied depending on the adhesive materials and, to a greater or lesser extent, on whether they showed antifungal activity. Two products (Cushion Collect and Collect Soft A) significantly suppressed C albicans growth (P < 0.01), and one product (Collect Soft A) effectively reduced C tropicalis growth (P < 0.01). Conclusion: Our results suggest that denture adhesives possess antifungal activity to a greater or lesser degree. However, one product caused the reduction of pH below 5.0. Thus, in the daily use of denture adhesives, attention should be paid to both the materials and their microbiologic properties.