Researchers from the University of Pennsylvania have developed a dental material tethered with an antimicrobial compound that can kill bacteria and resist biofilm growth. The material is also effective with minimal toxicity to the surrounding tissue, as it contains a low dose of the antimicrobial agent that kills only the bacteria that crosses it’s path.
The researchers were motivated to develop a new dental material because the current composite materials to perform restorative procedures, such as filling cavities, are vulnerable to the growth of plaque, the biofilm that leads to tooth decay. The researchers had two goals in mind when developing the dental biomaterial: 1) kill pathogenic microbes effectively, and 2) withstand severe mechanical stress. The newly developed material is composed of a resin embedded with the antibacterial agent imidazolium. Unlike some traditional biomaterials that slowly release a drug, this material is non-leachable and only kills microbes that touch it. The researchers feel that the slow release nature of the material can reduce the likelihood of antimicrobial resistance.
The dental material was tested in its ability to prevent growth of biofilms, to kill microbes, and to withstand mechanical stress. The results showed effectiveness in killing bacterial cells on contact and severely disrupting the ability of biofilms to grow on the surface. Only a negligible amount of biofilm matrix, glue that holds clusters of bacteria together, were able to accumulate on the material. This is different than traditional composite materials which show a steady accumulation of sticky biofilm matrix over time.
The researchers also explored how much shear force was required to remove the biofilm on the experimental material. A very small force was found to remove almost all the biofilm from the material. A force four times greater than this force was found to be incapable of removing the biofilm from the traditional composite material. The researchers are hopeful that the material developed could help better improve oral health in patients.
Source: Geelsu Hwang and et. al., Nonleachable Imidazolium-Incorporated Composite for Disruption of Bacterial Clustering, Exopolysaccharide-Matrix Assembly, and Enhanced Biofilm Removal, ACS Applied Materials & Interfaces, vol. 9, issue 44, 2017.