Influence of thermocycling on the antifungal properties of 3D printed denture base material containing zwitterionic and quaternary ammonium compounds

Abstract

Denture stomatitis, primarily caused by the colonization of Candida albicans biofilms, remains a persistent clinical challenge. This study investigated the effects of incorporating 2-methacryloyloxyethyl phosphorylcholine (MPC) and dimethyl dioctadecyl ammonium bromide (DDAM) into 3D-printed denture base resins to enhance their antifungal properties and evaluate their impact on flexural strength, even after undergoing thermocycling. Following simulated thermal aging (10,000 thermal cycles), all groups exhibited a decline in antifungal efficacy, with the most pronounced reduction observed in the 2% DDAM group. Notably, statistical analysis confirmed significant differences between before- and after-aging states, highlighting the impact of thermal aging on antifungal performance. In contrast, the flexural strength was better maintained in the MPC group, whereas an optimal balance between antifungal efficacy and mechanical performance was achieved in the combination group (1% MPC + 1% DDAM). Thermocycling demonstrated the long-term durability of the experimental resins, with a slight decline in antifungal activity over time. This study highlights the potential of MPC and DDAM as functional additives to enhance the antifungal properties of 3D-printed denture base resins while maintaining acceptable flexural strength, offering a promising strategy for addressing denture stomatitis.