Antifungal Properties of Experimental Antimicrobial Compounds and Denture Resins

Objectives: To test the antifungal properties of several newly synthesized novel antimicrobial compounds containing 1,4-diazabicyclo[2.2.2]octane (DARBCO) and experimental denture resins containing these compounds.
Methods: Six DARBCO derivatives with different aliphatic chains (DC16, DC18, C6DC16, DC16F), and methacrylate monomers (DC12MAF and C2DC12MAF) were synthesized. Experimental acrylic denture resins (discs-10mm dia., 2mm thick, n=5) were prepared by adding 4wt% of the synthesized compound or clotrimazole (positive control) to Ivocap High Impact (Ivoclar Vivadent) and heat cured according to manufacturer’s instructions. Discs without any compound were used as negative controls. Standard minimal inhibition concentration (MIC) assays were used to determine the fungicidal effect of DC16 against C. albicans, C. dubliniensis, C. glabrata, C. parapsilosis and C. tropicalis. MICs were also determined for the other compounds against C. albicans. Several denture resin-containing discs were additionally evaluated for inhibition of C. albicans biofilm formation utilizing the colorimetric XTT cell viability assay.
Results: DC16 has MIC 2-4 μg/mL against all tested fungi. MIC against C. albicans (4 μg/mL): DC18 (4), C6DC16 (2), DC16F (4), DC12MAF (1). These results are comparable to the commonly used static antifungal drugs, fluconazole and clotrimazole. Denture discs containing DC16F and DC12MAF showed near total inhibition of C. albicans biofilm formation at 24 h, whereas those with C2DC12MAF demonstrated only moderate inhibitory activity.
Conclusions: several compounds containing DARBCO have antifungal activity and can be integrated into acrylic-based denture materials to potentially prevent fungal-mediated denture stomatitis.