Blue-light DLP of high-performance dental 3YSZ ceramics: optimized sintering, mechanical reliability and biocompatibility

Purpose Additive manufacturing of zirconia dental restorations remains constrained by insufficient densification, mechanical properties and dimensional stability compared with computer-aided design and computer-aided manufacturing (CAD/CAM) processing. This study aims to establish a blue-light digital light processing (DLP) route for fabricating high-solid-loading 3 mol% yttria-stabilized zirconia (3YSZ) ceramics and to evaluate its suitability for high-performance dental applications. Design/methodology/approach High-solid-loading (58 Vol.%) 3YSZ slurries were processed using blue-light (465 nm) DLP stereolithography and pressureless sintering at 1400°C–1500°C. The effects of sintering temperature on densification behavior, microstructural evolution, mechanical properties, wear resistance and cytocompatibility were systematically investigated using density measurements, SEM, mechanical testing, tribological analysis and in-vitro cell viability assays. Findings Near-theoretical densities (5.92–5.95 g/cm3) with low porosity (0.16%–0.23%) and uniform linear shrinkage below 20% were achieved, indicating excellent dimensional stability. Optimized sintering at 1500°C produced fine-grained, highly densified microstructures with improved interlayer cohesion. The resulting ceramics exhibited a flexural strength of 799.34 ± 58.51 MPa in horizontal plane orientation and 625.96 ± 34.10 MPa in vertical plane orientation, a hardness of 13.66 ± 0.11 GPa and an elastic modulus of 109.50 ± 0.89 GPa, approaching those of conventionally manufactured zirconia. The flexural strength ratio σv/σh was 0.78, demonstrating low mechanical anisotropy. Wear resistance and cytocompatibility were comparable to clinical-grade zirconia ceramics. Originality/value This study proposes and validates a fabrication route combining an optimized high-solid-loading slurry formulation with blue-light DLP, overcoming the key limitations of UV-based stereolithography in processing high-solid-loading 3YSZ slurries and producing 3YSZ ceramics whose mechanical properties and dimensional stability approach those of CAD/CAM-manufactured counterparts. The authors systematically characterized the mechanical, tribological and biological properties of the resulting 3YSZ ceramics, providing critical data to support blue-light DLP as a viable manufacturing route for high-performance personalized dental restorations.