Mechanical properties and oral restoration applications of 3D printed aliphatic polyester-calcium composite materials

Three-dimensional (3D) printing of polymer-calcium phosphate composites has shown potential for fabricating customized scaffolds for bone regeneration. However, the application of such scaffolds for oral and maxillofacial restoration requires further investigation considering the complex mechanical and biological environment. This study aims to evaluate poly(lactic acid) (PLA) and polycaprolactone (PCL) composites reinforced with hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP) fabricated into 3D scaffolds using fused deposition modeling (FDM). The rheological properties, thermal behavior, scaffold architecture, mechanical properties, in vitro bioactivity, and cytocompatibility of the composites were characterized. The results showed shear-thinning behavior for all filaments with elastic moduli 10 times higher than viscous moduli, indicating suitability for FDM. PLA/HA scaffolds displayed apatite formation on surface after simulated body fluid exposure. Mechanical properties were tuned by varying polymer, ceramic content, and pore geometry. PLA/TCP10 scaffolds exhibited the highest compressive modulus (152 MPa), comparable to human trabecular bone. Oral fibroblasts and osteoblasts displayed good viability, spreading and proliferation on the composite scaffolds. Overall, the study demonstrates the potential of 3D printed PLA/TCP scaffolds with tailored architecture and mechanical properties for oral and craniofacial bone restoration; PCL/HA constructs showed limited printability and require further optimization.