Self-healing is one of the most desired material properties. Herein, we present
the design and development of a new self-healing dental composite (SHDC) that
can heal micro-cracks autonomously. The SHDC has two functional components in
addition to contemporary dental composites: healing powder (HP) and healing
liquid (HL) encapsulated in silica microcapsules. The autonomous healing is
triggered by micro-cracks which fracture microcapsules in their propagation path
and release the HL. As a consequence, the released HL dissolves and reacts with
the HP, and then fill the micro-cracks with a cement-like new material. This
3-step crack-release-heal process prevents micro-cracks from causing restoration
failure, thus improving the service life of dental restorative material. The
mechanical performance of the SHDC prepared were evaluated in terms of elastic
modulus and fracture toughness, which were in the upper level compared to
commercial dental restorative materials, and the self-healing capability was
confirmed through fracture toughness recovery test. In addition, the SHDCs were
made with clinically-tested, biocompatible materials, which makes them readily
applicable as medical devices.