Self-healing is one of the most desired material properties. Herein, we presentthe design and development of a new self-healing dental composite (SHDC) thatcan heal micro-cracks autonomously. The SHDC has two functional components inaddition to contemporary dental composites: healing powder (HP) and healingliquid (HL) encapsulated in silica microcapsules. The autonomous healing istriggered by micro-cracks which fracture microcapsules in their propagation pathand release the HL. As a consequence, the released HL dissolves and reacts withthe HP, and then fill the micro-cracks with a cement-like new material. This3-step crack-release-heal process prevents micro-cracks from causing restorationfailure, thus improving the service life of dental restorative material. Themechanical performance of the SHDC prepared were evaluated in terms of elasticmodulus and fracture toughness, which were in the upper level compared tocommercial dental restorative materials, and the self-healing capability wasconfirmed through fracture toughness recovery test. In addition, the SHDCs weremade with clinically-tested, biocompatible materials, which makes them readilyapplicable as medical devices.