3D Printing of PEEK as Substitute for Implant Components

Objectives: Poly-ether-ether-ketone (PEEK) is an ideal substitute material for bone tissue engineering, which can avoid the stress-shielding phenomenon due to its similar mechanical properties to natural human bone. 3D-printing offers a more efficiently way of manufacturing dental devices made of PEEK.
Methods: 3D models of objects were formulated (Catia, France) and converted into STL data that was then used to control the Fused deposition modeling (FDM) 3D printer (Indmatec GmbH, Germany). Specimens (n=5) in cylindrical shape with diameter of 4,5 and 6 mm and a height to diameter ration of 2:1 were fabricated, employing pure PEEK filaments (ρ=1.32 g/cm3) as source materials. Then compare them with traditional molded pure PEEK of the same size. Density of the specimens were measured on Kern YDB-03 (Kern&Sohn GmbH, Germany), elastic moduli and pressure strength were measured on the universal testing machine (Z010, Zwick GmbH&Co, Ulm, Germany).
Results: Results show that the density of 3D printed specimens have a tendency to increase as the size decrease, ranging from 1.14 to 1.24 g/cm3. The difference between them are significant (P＜0.05). There are no significant differences in elastic moduli (Ec) among the three experiment groups, the average Ec is 1.5±0.17 GPa. It is smaller than control group, whose Ec is 2.65±0.03GPa (d=4mm), 3.04±0.07GPa (d=5mm), 3.31±0.03 (d=6mm) separately. The compression strength of experiment group has the same tendency as density, the smaller the specimens are, the higher the pressure strength. The average pressure strength of the experiment groups are 94.86±4.06MPa (d=4mm), 87.68±3.22MPa (d=5mm), 79.56±5.8MPa (d=6mm), the difference among them are significant (P＜0.05). These results are smaller when compared to traditionally made pure PEEK with an average compression strength of 123.77±1MPa.
Conclusions: 3D-printing is a potential way of producing small complex-shaped implant components. Efforts are still needed to improve the quality of products of PEEK 3D-printer.