Evaluation of the efficiency of photodynamic therapy in disinfection of denture base material

The aim of this study was to evaluate the efficacy of indocyanine green (ICG) mediated photodynamic therapy (PDT) against C. albicans that can grow on denture base material. In order to imitate the denture base material, 108 polymethylmethacrylate (PMMA) discs of 2 mm thickness and 10 mm diameter were produced. The samples were contaminated with C. albicans and allowed to grow on surfaces of samples. Nine groups (n=11) were formed according to the procedures to be applied to acrylic discs with C. albicans reproduced on their surfaces. Groups; control group (K), nystatin (1 ml, 100,000 IU) applied group (N), microwave disinfection (650W, 3min) group (M), laser-only (810 nm, diode laser, continuous mode 30 sec, 24 J/ cm², 300 mW) group (L), group treated with ICG only at 10 mg/ml concentration (ICG10), and groups treated with ICG-mediated PDT at different concentrations (10, 5, 2 and 1 mg/ml) (L ICG10, L -ICG5, L-ICG2 and L-ICG1). After the procedures, colony counts of C. albicans biofilms on acrylic samples were made and SEM images of 1 more sample were taken for each group. L-ICG10, L-ICG5 and ICG10 groups were found to be effective in reducing the number of C. albicans colonies on the denture base. C. albicans was not detected in the cross-section of the L-ICG10 group in SEM images. In the cros-sections of K, N, M, ICG10, L, L-ICG5, L-ICG2, L-ICG1 groups, C. albicans were detected in yeast and hyphae forms. The application of disinfection with ICG-mediated PDT in the treatment of denture stomatitis has shown promising results, but further studies are needed to apply this method in the clinic and to determine safe protocols. Keywords: C. albicans, acrylic resin, denture stomatitis, photodynamic therapy (PDT), photosensitizer (PS), indocyanine green (ICG).