Influence of surface characteristics on the adhesion of Candida albicans to various denture lining materials

Objective. This study evaluated the influence of surface characteristics of various denture lining materials on the adherence of Candida albicans. Materials and methods. Four different types of materials (tissue conditioners, acrylic and silicone soft liners and hard reline materials) were selected. Disk-shaped material specimens were prepared and their surface roughness values (R-a) measured using a profilometer. The contact angles of four reference liquids were measured on the material surfaces and surface energy parameters (total surface energy, acid and base components, degree of hydrophobicity/hydrophilicity) of the materials were calculated in accordance with acid-base theory. Specimens were incubated with C. albicans and adhering fungi quantified using the colony counting method. Data were statistically analyzed using a one-way ANOVA with Games-Howell post-hoc test (alpha = 0.05). Pearson correlation analysis was applied to detect correlations between surface characteristics and Candida adhesion. Results. Significant differences in the surface roughness of the materials were found (p < 0.001). The acrylic soft liners were more hydrophilic than the other materials. Overall, the acrylic soft liners and tissue conditioners showed significantly greater Candida adhesion than silicone soft liners and hard reline materials (p < 0.05). The Pearson correlation analysis indicated that the base component and degree of hydrophobicity/hydrophilicity of the materials (p = 0.005/0.008), rather than the total surface energy and the surface roughness (p = 0.093/0.057), affected C. albicans adherence in a statistically significant way. Conclusions. The adhesion of C. albicans to denture lining materials can be accounted for in terms of interfacial acid-base interactions.