Furthermore, the self-healing composite displayed a strong antibacterial effect against dental plaque microcosm biofilms, inhibiting biofilm viability and lactic acid production, and reducing biofilm CFU by 3–4 log. These results, together with recent studies showing NACP with acid neutralization, lesion remineralization and inhibition of secondary caries in a human in situ model, indicate the promise of developing a composite addressing both the fracture issue (self-healing) and the caries issue (antibacterial and remineralization). The self-healing NACP-DMAHDM composite may be promising for tooth cavity restorations to combat bulk fracture and secondary caries. The method of using triple agents (self-healing microcapsules, NACP, DMAHDM) may have applicability to other composites, adhesives, cements and sealants in restorative and preventive dentistry.