Review: advances in photocurable 3D printing of calcium phosphate ceramics for bone tissue engineering

The convergence of calcium phosphate (CaP) ceramics with photopolymerization-based 3D printing is redefining strategies for bone tissue regeneration. Despite their widespread use, conventional CaP fabrication techniques suffer from inherent limitations in geometric precision and the ability to realize patient-specific implants, which has driven the exploration of advanced manufacturing strategies such as photopolymerization-based 3D printing. Unlike conventional fabrication routes, stereolithography (SLA), digital light processing (DLP), liquid crystal display (LCD), continuous liquid interface production (CLIP), and two-photon polymerization (TPP) enable precise control over architecture, porosity, and hierarchical design. These advances yield scaffolds that more faithfully mimic native bone, promote osteogenesis and angiogenesis, and can be tailored for patient-specific applications. Yet, critical barriers—including intrinsic ceramic brittleness, mismatched degradation kinetics, and limited photocurable slurry formulations—still constrain clinical translation. Emerging solutions, from biomimetic triply periodic minimal surfaces to hybrid sintering and ion-doped compositions, point toward next-generation CaP constructs with tunable mechanics and bioactivity. This review highlights recent breakthroughs and outlines a forward-looking roadmap for harnessing photopolymerized CaP ceramics as transformative scaffolds for bone repair.