In vitro comparison of the effect of photodynamic therapy with curcumin and methylene blue on Candida albicans colonies

Background and aim: Candida albicans (C. albicans) causes oral fungal infections. Considering the high prevalence of candidiasis, the toxicity of antifungal drugs, and the fungistatic property which develops drug-resistant species, the present study aimed to assess the effect of photodynamic therapy (PDT) with curcumin (CUR) and methylene blue (MB) photosensitizers and lasers with different exposure parameters on C. albicans colonies. Materials and methods: In this in-vitro experimental study, 150 samples of C. albicans standard strain (ATCC 10231) were examined using different combinations of CUR and MB photosensitizers with and without 460-nm and 660-nm laser irradiation with different exposure parameters in 15 groups of 10 samples each. The samples were cultured in microplates containing Sabouraud Dextrose Agar (SDA) medium, and the colony-forming units (CFU) were counted after 24 h of incubation at 37 degrees C. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey's test. Results: The maximum number of colonies was noted in the positive control group (CFU = 201,500 +/- 42,093), while the minimum number was detected in the 460-nm laser +10.2% CUR group (CFU = 10,100 +/- 2558), followed by the nystatin group (CFU = 22,300 +/- 5578). There was a significant statistical difference between the 460-nm laser + CUR group and other studied groups (P < 0.0001). Conclusion: The 460-nm laser in combination with CUR has the maximum antifungal efficiency against C. albicans.