Effects of S-PRG filler-containing denture adhesive on Candida albicans virulence-associated gene expression and cytotoxicity

OBJECTIVES: This study aimed to investigate the effects of incorporating surface pre-reacted glass-ionomer (S-PRG) filler into denture adhesives on virulence-associated gene expression in Candida albicans and to evaluate the cytotoxicity of these formulations. METHODS: Denture adhesives were prepared with S-PRG filler concentrations of 0 (control), 5, 7.5, and 10 wt%. C. albicans (ATCC 18804) was exposed to each formulation. The expression of lipase (LIP1-LIP10), secreted aspartyl proteinase (SAP1-SAP10), and biofilm-related genes (BCR1, RBT1, EAP1, and ECE1) was quantified using real-time polymerase chain reaction. Cytotoxicity was assessed by colony formation assays with V79 fibroblasts, in accordance with ISO 10993-5:2009, and the 50% inhibitory concentration was calculated for each group. RESULTS: S-PRG filler-containing denture adhesives suppressed the expression of most lipase genes (LIP1-LIP6 and LIP8-LIP10) and some SAP genes (SAP1, SAP3, and SAP8). Biofilm-associated genes involved in initial adhesion (BCR1 and RBT1) were consistently inhibited, suggesting a reduction in early biofilm formation. However, higher filler concentrations produced less consistent suppression, with SAP9 expression increasing for the 10 wt% formulation. Cytotoxicity testing demonstrated reduced cell viability with increasing filler content, indicating a concentration-dependent inhibitory effect on fibroblast growth. CONCLUSIONS: S-PRG filler-containing denture adhesives suppressed key virulence-related gene expression in C. albicans, suggesting a potential antimicrobial effect. However, high filler concentrations exhibited cytotoxic effects, indicating a need for further optimization to balance antifungal activity with biocompatibility. CLINICAL SIGNIFICANCE: S-PRG filler-containing denture adhesives may offer a dual clinical benefit by improving denture retention while suppressing Candida albicans virulence and biofilm-related gene expression, potentially reducing denture stomatitis and related systemic infections. Careful optimization is required to ensure biocompatibility and safe long-term use.