Process-Driven Optimization of FDM Porous PEEK Scaffolds for Alloplastic Bone Grafts

Polyether ether ketone (PEEK) has emerged as a high-performance biomaterial for orthopedic and craniofacial applications due to its exceptional mechanical properties, chemical stability, and biocompatibility. Despite its clinical potential, the additive manufacturing of PEEK, particularly through fused deposition modeling (FDM), remains a considerable technical challenge owing to the polymer's high melting point and narrow processing window. In this study, we report a novel and practical strategy for producing porous PEEK scaffolds with an optimized architecture suitable for bone graft applications. All initial CAD-based lattice designs failed under FDM processing conditions, consistently resulting in misprints with poor fidelity and structural inconsistencies. To address this, a process-driven approach through the adjustment of slicing parameters was adapted. Through iterative optimization, a reproducible scaffold design was achieved, with interconnected porosity and pore dimensions ranging from 100 to 400 μm, within the ideal range to support osteoblast adhesion, proliferation, and vascularization. The resulting scaffolds exhibited consistent morphology, mechanical integrity, and geometric fidelity, showing the importance of the slicing software parameters when used to circumvent computer-aided design limitations. This work demonstrates the pivotal role of manipulating the slicing software to unlock the full potential of high-performance thermoplastics such as PEEK in bone tissue engineering. Our findings offer a scalable pathway for producing customized, load-sharing scaffolds and open new avenues for integrating advanced manufacturing strategies in regenerative medicine.