Carbon Fiber Reinforced PEEK Composites Based on 3D-Printing Technology for Orthopedic and Dental Applications

Abstract

Fused deposition modeling (FDM) is a rapidly growing three-dimensional (3D) printing technology and has great potential in medicine. Polyether-ether-ketone (PEEK) is a biocompatible high-performance polymer, which is suitable to be used as an orthopedic/dental implant material. However, the mechanical properties and biocompatibility of FDM-printed PEEK and its composites are still not clear. In this study, FDM-printed pure PEEK and carbon fiber reinforced PEEK (CFR-PEEK) composite were successfully fabricated by FDM and characterized by mechanical tests. Moreover, the sample surfaces were modified with polishing and sandblasting methods to analyze the influence of surface roughness and topography on general biocompatibility (cytotoxicity) and cell adhesion. The results indicated that the printed CFR-PEEK samples had significantly higher general mechanical strengths than the printed pure PEEK (even though there was no statistical difference in compressive strength). Both PEEK and CFR-PEEK materials showed good biocompatibility with and without surface modification. Cell densities on the “as-printed” PEEK and the CFR-PEEK sample surfaces were significantly higher than on the corresponding polished and sandblasted samples. Therefore, the FDM-printed CFR-PEEK composite with proper mechanical strengths has potential as a biomaterial for bone grafting and tissue engineering applications.

Parameters Influencing the Outcome of Additive Manufacturing of Tiny Medical Devices Based on PEEK

“…The maximal tensile, bending, and compression strength of 3D printed pure PEEK specimens are similar or even better than the reference as seen in Table 2. Carbon-fiber-reinforced PEEK performs as a substitute for traditionally processed PEEK [19,23,26].…”

“…In the special case of PEEK printing with FDM, the not highly related parameters are either not involved, such as power characteristics and binder characteristics, or of secondary priority for small parts, such as fill pattern and support structure. Methods for the characterization of printed PEEK samples are mainly scanning electron microscope (SEM) [15,22,23], 3D scanner [15], differential scanning calorimetry (DSC) [13], and water contact angle measurements [23]. These methods mainly assess the dimensional accuracy, surface roughness, microstructure of interface, and crystalline ratio of printed PEEK objects.…”

“…If the nozzle temperature is too high, chain cleavage might occur and possibly leading to decomposition [15]. Nozzle temperatures have been explored within a range from 340 • C to 480 • C [13,[15][16][17][18][20][21][22][23]. Wu et al [15] found when the nozzle temperature is 350 • C, the warping deformation of PEEK samples is minimal.…”

“…Vaezi et al [17] identified a plate temperature of 130 • C and an ambient temperature of 80 • C as applicable conditions for an extrusion rate of 2.2 mg/s. Han et al [23] kept the printed PEEK samples in a furnace for 2 h at 300 • C, and let them cool down at room temperature afterward. When the temperature rises above T g , there will be a thermodynamic tendency for the polymer to continue to form crystals or to recrystallize [1].…”

“…They concluded that during the FDM of PEEK, the melt pressure directly affects the surface morphology and extrusion diameter of the filament, and higher melt pressure is beneficial for the reduction of surface defects on the extruded filament. Rahman et al [18] took a printing speed of 50 mm/s in their experiments while Han et al [23] applied a printing speed of 40 mm/s in theirs. Deng et al [20] achieved optimal tensile properties for PEEK specimens when the printing speed was 60 mm/s.…”