Comparative evaluation of surface morphology and Candida albicans adherence among conventional heat-polymerised PMMA, high-impact PMMA, and flexible denture base resins: an in vitro study

Candida albicans adherence to denture base materials is a critical initial step in biofilm formation and the development of denture stomatitis. Surface morphology may influence microbial colonisation; however, comparative evidence regarding conventional heat-polymerised polymethyl methacrylate (PMMA), high-impact PMMA, and flexible denture base resin remains scarce. This in vitro study compared the qualitative surface morphology and C. albicans adherence of these commonly used denture base materials. Thirty-six standardised disc-shaped specimens ( n = 12/group) were fabricated from conventional heat-polymerised PMMA, high-impact PMMA, and flexible denture base resin. A clinical isolate of C. albicans was identified using the germ tube test, and a standardised inoculum was prepared. Sterilised specimens were inoculated with the fungal suspension, incubated for 48 h, and fungal adherence was quantified by colony-forming unit (CFU) enumeration. Surface morphology was qualitatively evaluated using scanning electron microscopy (SEM). Data were analysed using one-way analysis of variance (ANOVA), with statistical significance set at p < 0.05. Mean C. albicans adherence was 5.417 ± 1.443 CFU/mL for conventional PMMA, 2.833 ± 1.528 CFU/mL for flexible denture base resin, and 0.500 ± 0.522 CFU/mL for high-impact PMMA. The overall difference among the three materials was statistically significant (F = 46.435, p < 0.001). SEM revealed distinct qualitative differences in surface morphology: conventional PMMA exhibited greater surface irregularities, high-impact PMMA showed a smoother, more homogeneous surface, and flexible denture base resin displayed intermediate characteristics. Within the limitations of this in vitro study, a statistically significant overall difference in C. albicans adherence was observed among the three denture base materials. High-impact PMMA showed the lowest mean fungal adherence and a comparatively homogeneous surface morphology, whereas conventional PMMA showed the highest mean adherence and greater surface irregularity. Further laboratory and clinical studies are required to validate these findings.