Engineering a Biomimetic DentinLayer via Light‐Responsive Self‐Mineralizing Collagen Matrix for Dentin Repair

Abstract Tooth integrity is essential for maintaining oral and systemic health. Dentin degradation poses a significant clinical burden, as exposed dentinal tubules serve as direct pathways for irritants and pathogens, triggering pain, inflammation, and irreversible pulp damage. Although biomimetic mineralization holds great promise for dentin regeneration, its clinical translation remains hindered by ineffective mineralization templates due to collagen degradation, poor mineral precursor delivery, and insufficient dentin–pulp complex restoration. Inspired by natural biomineralization, a biomimetic DentinLayer is constructed by photo‐crosslinking methacrylated type I collagen (ColMA) with methacrylated polyacrylic acid‐stabilized amorphous calcium phosphate (PMA@ACP), forming a composite hydrogel (ColPMA@ACP) that induces spontaneous intrafibrillar mineralization of both native and applied collagen. Both in vitro and in vivo studies confirm that ColPMA@ACP facilitates rapid collagen mineralization, effectively occludes dentinal tubules, restores dentin mechanical integrity, and creates a favorable microenvironment that supports reparative dentin formation and attenuates pain‐related neural signaling. This multifunctional biomimetic DentinLayer offers a minimally invasive, clinically translatable strategy that integrates structural reconstruction, mineralization templating, and autonomous mineralization to effectively restore the structure, function, and bioactivity of dentin. It provides a new approach for dentin defect repair and offers a versatile framework for the development of bioinspired materials in regenerative dentistry.