Bifunctional Anticaries Ionic Liquids With Antibacterial And Remineralizing Effects

Effective caries control relies on reducing cariogenic bacteria and promoting remineralization. This study aimed to develop bifunctional anticaries ionic liquids (ILs) that integrate antibacterial and remineralizing properties. Two bifunctional imidazolium-based ionic liquids (IL-F and IL-Sr) were synthesized. These ILs incorporate imidazolium cations modified with silane coupling agents for durable adhesion to tooth surfaces, paired with F⁻ and Sr²⁺ ions to enable remineralization. Their properties were evaluated through the following in vitro assays: (a) determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Streptococcus mutans (S. mutans); (b)inhibition of S. mutans biofilm formation; (c)remineralization effects on early caries lesions; (d)cytocompatibility assessment with L929 cells. Finally, the anticaries efficacy was validated in a rat caries model. The ionic liquids (ILs) exhibited MIC/MBC values of 25 μM against S. mutans, achieving 98.66% bactericidal efficacy within 1 hour at this concentration, while remaining non-toxic to L929 cells within the effective concentration range; 12.5 μM ILs significantly suppressed biofilm formation. IL-F repaired acid-etched enamel defects through surface mineralized deposits, restoring over 60% of microhardness (p < 0.0001) after 7 days, whereas IL-Sr occluded dentinal tubules with mineralized deposits and enhanced acid resistance. In rat models, ILs persistently adhered to tooth surfaces, effectively inhibiting caries initiation and progression while demonstrating favorable biocompatibility. This study developed novel dual-functional ILs with synergistic antibacterial and remineralizing capabilities, demonstrating significant scientific merit and translational potential for caries prevention.