Dual-Functional Microcapsules with Antibacterial and Self-Healing Properties for Dental Resin

Background: Current self-healing microcapsules for dental composites have been developed toward multifunctional properties. Antibacterial microcapsules are commonly loaded with antibacterial agents on their surfaces. Nevertheless, restricted microcapsule incorporation within composite resin limits their antibacterial properties. For the complex oral environment, further enhancement of antibacterial properties of microcapsules is still required; Methods: This study aimed to fabricate microcapsules co-encapsulating non-polymerized methacryloyloxyethyl trimethyl ammonium chloride (METAC) and healing monomers via in situ polymerization. The morphology, particle size distribution, chemical composition, thermal stability and antibacterial activity were characterized. The experimental dental resin containing the microcapsules was fabricated, and its flexural properties, antibacterial activity, self-healing efficiency and cytotoxicity were evaluated; Results: The 6 wt% METAC loading and 10 wt% microcapsule incorporation ratio were selected within the investigated ranges. At this formulation, the surface-scratched dental resin exhibited 61.82% antibacterial efficiency against S. mutans relative to the METAC-free control, with no significant decline in activity after 28-day aging. It also achieved a self-healing efficiency of 25.7% and showed no discernible cytotoxicity under the tested in vitro conditions; Conclusions: The prepared microcapsules achieved antibacterial and self-healing properties, and no statistically significant difference in self-healing gain was detected between the METAC-loaded and METAC-free groups. Incorporation of these microcapsules into dental resin is expected to enhance its antibacterial potential.