F1 - Porosity Effects on the Mechanical Properties of 3D-printed PEEK Osteoconductive Scaffolds

Introduction: : Polyether-ether-ketone (PEEK) is a high-performance thermoplastic polymer recognized for its superior mechanical properties and biocompatibility, making it a promising candidate for orthopedic applications [1]. However, its bioinert nature limits its ability to integrate with bone, which hinders its use in bone scaffolds. To address this limitation, research has focused on using porous scaffolds to enhance osteointegration in PEEK implants [2]. Additive manufacturing, particularly 3D printing, has revolutionized the fabrication of these scaffolds, enabling the production of patient-specific osteoconductive scaffolds that can match the unique anatomical needs of individual patients. Despite these advancements, the relationship between porosity and the mechanical properties of 3D-printed PEEK remains poorly understood. This study investigates the effects of varying porosity levels in 3D-printed PEEK specimens to determine the optimal porosity for promoting osteointegration while maintaining mechanical integrity.

Materials and

Methods: : PEEK filament will be processed using a CreatBot PEEK-300 3D-printer to fabricate test specimens. The dimensions of the specimens will follow ASTM D256 and ASTM D695 standards for impact and compression testing, respectively. The mechanical properties such as compressive strength, modulus, and impact strength will be evaluated. The specimens will be printed with different porosity levels by adjusting the geometry and pores per inch (PPI) in the CAD design, as illustrated in Figure 1a. Printing parameters, including nozzle temperature (430°C), heated bed temperature (150°C), and chamber temperature (120°C), will be precisely controlled to ensure accurate fabrication, as shown in Figure 1b.

Results, Conclusions, and Discussions:: To ensure accurate fabrication, the porosity of the 3D-printed specimens will be examined after manufacturing. Heat treatment through annealing will be applied post-fabrication to enhance mechanical properties of the scaffolds. Mechanical testing, including compression and impact tests, will be performed to examine the relationship between porosity levels and mechanical properties. Statistical analysis will identify trends and correlations, allowing for the determination of the optimal porosity for load bearing osteoconductive scaffolds.

Acknowledgements and/or References (Optional):: Reference:
[1] M Chen, Z., Chen, Y., Wang, Y., Deng, J., Wang, X., Wang, Q., Liu, Y., Ding, J., & Yu, L. (2023). Polyetheretherketone implants with hierarchical porous structure for boosted osseointegration. Biomaterials Research, 27(1), 61. https://doi.org/10.1186/s40824-023-00407-5
[2] Gummadi, S. K., Saini, A., Owusu-Danquah, J. S., & Sikder, P. (2022). Mechanical properties of 3d-printed porous poly-ether-ether-ketone (Peek) orthopedic scaffolds. JOM, 74(9), 3379–3391. https://doi.org/10.1007/s11837-022-05361-6