Photocurable ionized vinylimidazole liquid salt for antibacterial application

There has been an increasing demand for antibacterial dental composite as it can prevent the biofilm formation and the adhesion of bacteria after the treatment causing the consequential cavities. Previous study explored the antibacterial activity of the heterogenous mixture of heterocyclic polymer and resin. It showed limitations as the mixture did not show antibacterial activity since the mixture could only contain a small amount of heterocyclic polymer within the resin due to its inconvenience of shaping and low miscibility. To overcome this limitation, this research focused on synthesizing heterocyclic antibacterial monomer liquid salt and curing it with UV light to potentially serve as an antibacterial dental composite.

Vinylimidazole, iodoalkane, and ethyl acetate is used to synthesize vinylimidazole salt. It produced two liquid layers with a clear yellow bottom layer which was extracted and dried. The product was a yellow liquid ionized salt. For curing the ionized salt, the product was stirred with tetra (ethylene glycol) diacrylate (TEGDA) and 2,2-dimethoxy-2-phenylacetophenone. The liquid was exposed to UV light and was polymerized.

To test the antibacterial activity, the ionized salt was tested with a disk diffusion test. The bacteria chosen for testing was Streptococcus Mutans (S. Mutans). Antibiotics (ampicillin), vinylimidazolium salt, vinylimidazole, and TEGDA were tested. The zone of inhibition was measured after incubation. It showed a zone of inhibition for ampicillin, vinylimidazolium salt, and TEGDA. However, the starting material, vinylimidazole, did not show any zone of inhibition. It was clearly shown that vinylimidazolium salt and TEGDA had produced a zone of inhibition resulting in the presence of antibacterial activity against S. mutans.