Influence of roughness and surface free energy on adhesion and biofilm formation of Candida albicans to polymeric materials

Abstract Objectives Denture-associated candidiasis can lead to severe oral infections and is typically caused by the yeast Candida albicans ( C. albicans ). This study examines how the adhesion and biofilm formation of C. albicans on polymeric materials is influenced by their roughness, surface free energy (SFE) and saliva coating. Methods For this purpose, three standard polymeric materials (polyvinyl chloride (PVC), polytetrafluorethylene (PTFE), polyethylene (PE)) with two roughnesses (treatment A R a = 0.2 µm and treatment B R a = 0.04 µm) were characterized using profilometry, contact angle measurements, confocal laser scanning microscopy, and scanning electron microscopy. Adhesion and biofilm formation of C. albicans (DSM 1386) were quantified by fluorescence staining and confocal microscopy. Results Surface free energy (SFE) significantly influenced both initial adhesion and biofilm formation, with lower SFE generally reducing these processes. PTFE (SFE ≈ 17.73 mJ/m²) exhibited a lower adhesion volume than PE (SFE ≈ 32.59 mJ/m²). Roughness variations affected only C. adhesion by altering SFE and available surface area. Saliva treatment generally decreased adhesion and biofilm formation and also reduced the formation of virulent hyphae. Conclusion Material specific SFE had the strongest influence on yeast adhesion and biofilm formation. Therefore, reducing the SFE could help to minimize C. albicans adhesion and biofilm formation, and potentially lower the risk of denture stomatitis.