COMPARATIVE EVALUATION OF CANDIDA ALBICANS ADHERENCE ON DIGITALLY AND CONVENTIONALLY FABRICATED DENTURE BASE POLYMERS: AN IN-VITRO STUDY

Abstract

Objectives: This study aimed to evaluate the adherence of Candida albicans to different denture base materials and to determine the impact of surface roughness and material composition on microbial colonization. The materials tested were conventional heat-polymerized polymethyl methacrylate (CH), 3D-printed PolyJet (PJ), 3D-printed SLA (PF), and milled polymethyl methacrylate (MI), each in both polished (P) and unpolished (UP) states. Methods: C. albicans adherence was quantitatively assessed by using a crystal violet assay. Specimens of CH, PJ, PF, and MI denture base materials were prepared in both polished and unpolished forms. Biofilms were stained with crystal violet and destained using 70% ethanol, and the optical density was measured at 600 nm (OD600) to quantify biofilm formation. Scanning Electron Microscopy (SEM) provided qualitative insights into surface morphology and biofilm coverage. One-way ANOVA and Tukey's multiple comparisons tests were used to analyze the differences in microbial adherence across material groups. Results: The study revealed significant differences in C. albicans adherence across the denture base materials. PJ materials exhibited the highest adherence, particularly in the unpolished state, with significant increases in OD600 values (P < 0.0001). CH materials showed moderate adherence, with unpolished specimens adhering more significantly compared with polished specimens (P = 0.0014). MI and PF materials demonstrated the lowest adherence levels, with no significant differences between polished and unpolished specimens, indicating minimal susceptibility to microbial colonization. SEM analysis corroborated these results, displaying dense biofilm on rougher surfaces such as PJ and unpolished CH and minimal biofilm on smoother surfaces such as MI. Conclusion: Surface roughness and material composition significantly influenced C. albicans adherence to denture base materials. Rougher surfaces, such as those found in PJ and unpolished CH, facilitated greater microbial colonization, which may increase the risk of denture-related stomatitis. In contrast, smoother materials such as MI and PF resisted biofilm formation and would be preferable for patients at higher risk of fungal infections.