Biofilm formation on denture liners in a randomised controlled in situ trial

Abstract Objectives This randomised clinical trial assessed how biofilm development and composition is affected by time and denture material type in denture wearers with and without denture stomatitis. Methods Specimens of acrylic resin (control) and denture liners (silicone-based or acrylic resin based, depending on the experimental phase) were inserted into the surface intaglio of 30 denture wearers. Biofilm was formed in two phases of 21 days, and counts of viable micro-organisms in the accumulating biofilm were determined after 7, 14 and 21days of biofilm formation. Data were analysed by three-way ANOVA followed by Tukey test to assess differences among health condition (healthy or with denture stomatitis), materials and time point. Results Non- albicans Candida species counts were higher in diseased patients with silicone-based denture liners ( p = 0.01). Denture stomatitis patients showed higher mutans streptococci counts after 7 days ( p = 0.0041). Conclusions Longer biofilm formation time periods did not result in differences on biofilm composition. The denture liners evaluated in this study accumulate greater amount of biofilm, and therefore their use should be carefully planned. Clinical significance The silicone-based denture liner tested should be used cautiously in patients with denture stomatitis as it showed increased non- albicans species counts, known to be difficult to treat.