In situ biomimetic materials for dentin repair

Abstract Dental defects, ranking among the most prevalent diseases globally, pose a serious threat to human health, with extensive defects involving dentin leading to complications such as pulp and periodontal diseases, as well as maxillofacial dysfunctions, significantly impairing quality of life. Current clinical treatments primarily rely on rigid materials such as metals, composite resins, and ceramics for macroscopic filling. However, their inherent limitations, differences in compositional and structural characteristics from natural dentin, mismatched mechanical properties, and interfacial adhesion instability, fail to meet the clinical demand for long‐term and stable restoration of natural dentin. In situ dentin regeneration, inspired by the complex composition and hierarchical structure of natural dentin, aims to induce the autonomous repair of dentin. This approach effectively overcomes the traditional limitations, shifting from traditional passive filling to active regenerative repair. Based on the growth direction and mineralization pattern of the repair layer, current research focuses on three strategies: “inward growth”, “outward growth”, and “synchronized inward‐outward growth”. This review primarily focuses on the roles and clinical applications of key bioactive materials in these strategies, providing a feasible basis for future material and performance optimization of dentin in situ regeneration.