3D-printed Polyetheretherketone Research Articles

Mechanical and surface characterisation of additively manufactured polyetheretherketone for the tribo test

Purpose The additive manufacturing process, such as fused filament fabrication based on material extrusion, fabricates the samples layer-by-layer. The various parameters in the process significantly affect the dimensions, structure and mechanical properties of the fabricated parts. The purpose of this paper is to investigate the surface and mechanical properties that can affect the contact characteristics with other materials during tribological tests. Design/methodology/approach The investigation of 3D-printed Polyetheretherketone (PEEK) includes the measurement of dimensions, microhardness, surface roughness, surface energy and tensile strength to define material characteristics. The crystallinity is measured using an X-ray diffractometer to understand the hardness behaviour. Findings The printing parameters affect its surface roughness, hardness and crystallinity. This change in parameters such as layer thickness and infill density impacts mechanical properties such as hardness and surface roughness, which will influence the contact mechanism with the counter body during any tribological test. The change in a single parameter during the sample fabrication and the change in the surface and mechanical properties are observed. Research limitations/implications The material cost plays an important role in conducting numerous destructive tests, which is a major limitation to conducting parameter optimisation by varying more parameters. The study is limited to the as-fabricated samples rather than finished samples and without any heat treatment. Achieving optimal parameters is integral to the success of additive manufacturing, ensuring the production of components with consistent performance. Practical implications The study aims at the application of 3D-printed PEEK for bush or journal bearings that can be directly used in practice. The mechanical properties discussed in this paper can fill the gap between theory and practice. Social implications The research provides all fundamental properties, including the printing parameters and their effect on the dimensions and surface structure, which are required to understand the material and its use. The results are consistent as at least four samples were tested for tribological behaviour. The conclusion is updated as per suggestions. Originality/value The study outlines the relationship between the change in layer thickness and infill density with changes in surface energy, surface roughness, hardness and tensile strength. The deformation and adhesion during the friction test depend on these properties.

Assessments and Investigation of Process Parameter Impacts on Surface Roughness, Microstructure, Tensile Strength, and Porosity of 3Dprinted Polyetherether Ketone (PEEK) Materials:

Additive manufacturing (AM) is emerging as a competitive technology with promising applications across various sectors, including biomedical, automotive, construction, and dental implants. This study investigates the influence of key process parameters on the surface roughness, microstructure, tensile strength, and porosity of Polyether Ether Ketone (PEEK), a high-performance thermoplastic used in dental prosthetics. Traditionally, metals and ceramics have been the standard for dental restorations, but advancements in computer-aided design (CAD) and computer-aided manufacturing (CAM) have improved accuracy, particularly for implant-supported prostheses. However, conventional methods like CAD-milling face challenges such as material waste and tool wear. AM techniques, such as fused deposition modeling (FDM), offer a solution by constructing objects layer by layer, minimizing waste. This research explores the effects of nozzle temperature on the mechanical properties of 3D-printed PEEK, emphasizing its role in optimizing performance and minimizing issues like porosity. Key factors like surface roughness and microstructure are highlighted as critical to the biocompatibility and longevity of dental restorations. The study identifies the optimal nozzle temperature range for PEEK 380-440°C, noting that deviations from this range lead to compromised mechanical properties. Overall, the findings provide valuable insights into optimizing the AM process for PEEK in dental applications and suggest that further biological and chemical studies are necessary to fully realize the material's potential in replacing traditional dental restoration materials.

A comparative quantitative assessment of 3D-printed PEKK and PEEK thin meshes in customized alveolar bone augmentation

ObjectiveCustomized nonabsorbable membranes are widely used in severe alveolar bone defects and provide sufficient and precise regenerated bone tissue for subsequent dental implant placement. Although 3D-printed polyetheretherketone (PEEK) meshes have confirmed successful use in clinical cases, the performance of a PEEK mesh is not satisfactory. Compared with PEEK, polyetherketoneketone (PEKK) has better mechanical and processing properties. However, whether PEKK is suitable for making customized membranes remains unclear. The objectives of this study were (1) to evaluate the printing precision, surface characteristics, mechanical characteristics and biocompatibility of the PEKK mesh and (2) to compare the properties of the PEKK and PEEK meshes.Materials and methodsBoth PEKK and PEEK meshes were designed and manufactured via additive manufacturing technology combined with computer-aided design (CAD). The printing precision was evaluated with a high-resolution extraoral scanner. The surface characteristics were evaluated with a contact angle system and three-dimensional optical microscopy. The mechanical characteristics were evaluated via three-point bending tests and tensile tests. The biocompatibility was evaluated with a CCK-8 assay, live/dead viability assay and qRT-PCT.ResultsCompared with the PEEK mesh, the PEKK mesh exhibited better control in terms of the thickness and aperture area. Both the PEKK mesh and the PEEK mesh had a hydrophobic surface, but the PEKK mesh had a smoother surface. Compared with the PEEK mesh, the PEKK mesh has better compression and tensile properties. Both the PEKK mesh and the PEEK mesh had good biocompatibility. The proliferation of cells on the PEKK mesh was slightly lower than that on the PEEK mesh.ConclusionsCompared with PEEK mesh, PEKK mesh has greater printing accuracy, smoother surfaces, better mechanical properties and similar biocompatibility and is expected to be used in the production of customized barrier membranes for the augmentation of severe bone defects. To ensure the stability of the mesh for clinical application, it is best to control the aperture diameter of the PEKK mesh to less than 2 mm with a thickness of 0.2 μm.

Patient-specific 3D-Printed PEEK implants for spinal tumor surgery

Aims & objectivesThis study evaluates the feasibility and clinical outcomes of using 3D-printed polyetheretherketone (PEEK) patient-specific implants (PSI) for vertebral body replacement (VBR) in patients with spinal tumors. The research question focuses on postoperative results, implant integration, and complications over a 12-month period. MethodsA single-center, retrospective case series analyzed five patients who underwent spinal reconstruction after tumor resection using PEEK 3D VBR between April 2022 and June 2023. Inclusion criteria were thoracic/lumbar spinal tumors, tumor resection with PEEK 3D VBR reconstruction, and follow-up exceeding 12 months. PEEK implants were created using fused filament fabrication from medical-grade PEEK. Patient data included demographics, medical history, tumor characteristics, and surgical outcomes. Radiological evaluations assessed bony fusion, local angle changes, and segment height stability. Descriptive statistical analyses were performed using R software. ResultsThe mean follow-up duration was 19.2 months. All patients remained alive, with one experiencing local recurrence. Postoperative imaging showed a decrease in local angle with no significant changes during follow-up. Segment heights remained stable, and no PEEK 3D VBR subsidence or hardware failure was observed. Bony fusion was observed in all patients. ConclusionsThe use of PEEK 3D printed PSI for VBR in spinal tumor patients demonstrates promising feasibility and clinical outcomes, with stable implant integration and minimal complications over a 12-month period. Further studies with larger cohorts are recommended to validate these findings.

Effect of the infill percentage of 3D printed Polyetheretherketone under the dry sliding condition

Sliding bearings made of advanced polymers like Polyetheretherketone (PEEK) are preferred for medium and heavy-duty applications. The high-temperature additive manufacturing process permits the efficient fabrication of lighter porous parts using high-cost materials like PEEK. Customised geometries and surface features are easily achievable using an additive manufacturing process and facilitate design for the required performance. The 3D-print parameters employed affect the surface characteristics and are investigated. The variation in infill porosity is found to affect the crystallinity, hardness, modulus, and surface roughness of the printed samples. The friction coefficient variation, wear resistance, and temperature rise in the 3D-printed PEEK samples are studied when slid against steel discs under dry sliding conditions. The material transfer between surfaces varies based on the sample's surface properties and porosity, significantly affecting friction and wear behaviour. Accumulation and strong adhesion of wear debris in the groves of PEEK samples contribute to improved wear resistance. The temperature rise in the polymer sample also depends on the infill porosity, and a reduced temperature rise is observed in porous samples, which will improve the life when used in bearings.

Microstructural and biological characterization of 3D printed PEEK scaffolds coated with alginate/CNT for bone regeneration applications

The main aim of bone tissue engineering is to develop novel scaffold structures that integrate biological functionality with sufficient mechanical strength and properties. In this study, bone scaffolds were fabricated using polyether ether ketone (PEEK) via 3D printing, resulting in three different porous designs. To enhance their biological attributes, these scaffolds were coated with an alginate and carbon nanotube (CNT) composite using a freeze-drying technique. The biological characteristics of fabricated samples, such as biocompatibility and bioactivity, were evaluated in simulated body fluid (SBF). Field emission scanning electron microscopy (FE-SEM) analysis showed that the 3D-printed PEEK scaffolds had a porous, uniform, and interconnected architecture with pore sizes between 321–378 µm. Energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) confirmed the formation of hydroxyapatite (HA) and bioactive calcium phosphate (Ca-P) on the scaffold surfaces, indicating their bioactivity. Cell biocompatibility was assessed using the MTT assay, which revealed a high cell viability rate of approximately 97% and no significant toxicity. Consequently, the 3D-printed PEEK scaffold coated with Alginate/0.3%wt CNT demonstrated promising microstructure, bioactivity, and biocompatibility, making it suitable for bone tissue regeneration.Graphical abstract

In vitro assessment of corrosion, antibacterial properties, and degradation behavior of zirconia-coated polyetheretherketone (PEEK)

The medical industry often uses ceramic and polymeric coatings to safeguard metal substrates. However, more investigation is required to explore the implementation of ceramic coatings on polymer substrates and to determine their degradation and in vitro characteristics. This work involves applying zirconia coating onto the 3D-printed PEEK polymer substrate using the RF magnetron sputtering technique. With varying layer thickness and printing speed parameters, PEEK samples (S1, S2, S3, and S4) were 3D printed and coated with zirconia. The coated and uncoated samples were immersed in Fusayama artificial saliva solution for 30 days. Following immersion in artificial saliva, this study examined the corrosion of 3D-printed PEEK samples with and without coatings. Elemental mapping, field emission scanning electron microscopy, and X-ray photoelectron spectroscopy were employed to evaluate sample morphology and estimate the binding energy of possible compounds generated in the artificial saliva solution. In vitro assessments such as antibacterial studies were performed against E. coli and S. aureus, and cytotoxic analysis was performed using Human Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs) to determine cell proliferation. The results indicated that sample S3, printed with 0.15 mm layer thickness and 20 mm/s print speed coated with zirconia showed a better degradation rate of 9.01% whereas the other three samples S1, S2, and S4 coated with zirconia showed deterioration rates of 36.4%, 33% and 16% respectively. Sample S3 showed a better antibacterial activity as biofilm formation was absent and also showed cell viability of about 79% and hence can be considered as a viable option for dental applications.

The Anisotropic Mechanical and Tribological Behaviors of Additively Manufactured (Material Extrusion) Implant-Grade Polyether Ether Ketone (PEEK)

In this study, we investigated the mechanical and tribological properties of the layer-by-layer structure of additively manufactured implant-grade Polyether Ether Ketone (PEEK) through the Material Extrusion (ME) process as a potential substitute for artificial joints. The effective elasticity modulus of the anisotropic 3D-printed PEEK was determined to be 2.505 GPa along the vertical and horizontal build orientations. The lubricated friction and wear performance were assessed using a pin-on-disk test under various loads, including 14, 30, 50, and 70 N, with a sliding speed of 50 mm/s over a total distance of 1 km at 37 °C. The contact parameters between the hemispherical steel pin and 3D-printed PEEK disks, involving contact pressures over the circle of contact, were observed to increase as the load increased. The results indicated that the wear coefficient exhibited a rise from 1.418 × 10−5 to 2.089 × 10−1 as the applied loads increased, signaling a shift from mild to severe wear regimes. Fetal Bovine Serum (FBS) as a lubricant exhibited a mixed mechanism, ascertained through the Stribeck curve, as well as a minimum fluid film thickness of 1.346 nm under an isoviscous–elastic regime, as calculated by the maximum load. Moreover, the mechanism governing wear during sliding, influenced by both normal axial and shear loads, primarily involved adhesion.

Investigating the Impact of Pore Size and Specification on Soft Tissue Ingrowth in 3D-Printed PEEK Material.

Bone pelvis tumor resection and reconstruction is a complex surgical procedure that poses challenges in soft tissue reconstruction despite advancements in stabilizing pelvic structure. This study aims to investigate the potential of using Polyetheretherketone (PEEK) material in repairing and reconstructing soft tissues surrounding pelvic implants. Specifically, the study focuses on exploring the effectiveness of 3D printed porous PEEK material in promoting cell growth and adhesion. The interaction between PEEK materials with different pore sizes (200, 400, 600µm) and different specifications (through-hole (T)/non-through-hole (C)) is evaluated by cell experiments and animal experiments. The soft tissue ingrowth potential of PEEK materials is evaluated by cell growth and adhesion observation. The findings indicate that PEEK material, particularly the T400 variant, exhibits stronger interaction with muscle tissue compared to its interaction with bone and fibrous tissue. The moderately sized pores present in the T400 material facilitate enhanced cell adhesion and penetration, thereby promoting cell growth and differentiation. PEEK materials with through-hole structures show promise for applications involving the repair and reconstruction of soft tissues and muscle tissue. The study provides valuable insights into the development and application of biomedical materials, specifically PEEK, contributing to the advancement of pelvic tumor resection and reconstruction techniques.

An analysis of clinical application effects of 3d-printed act titanium trabecular intervertebral fusion cage in posterior lumbar interbody fusion (PLIF).

To compare the clinical effects of applying a 3D-printed ACT titanium trabecular intervertebral fusion cage and a Polyetheretherketone (PEEK) cage in posterior lumbar interbody fusion (PLIF). This was a clinical comparative study. Forty patients with degenerative lumbar diseases admitted at The Second People's Hospital of Dalian from January 2020 to December 2021 were selected and divided into an observation group (3D cage) and a control group (PEEK cage) using the random number table method, with each group of 20 cases. The visual analogue scale (VAS) scores, Japanese Orthopaedic Association (JOA) scores, Cobb angles at fusion segments, intervertebral height and intervertebral fusion situations of the patients between the groups were compared. No significant differences were found in their operation time, intraoperative blood losses and operation related complications(p>0.05). In terms of postoperative VAS and JOA scores in both groups, they are all significantly improved compared with those before the operation, and their differences are also statistically significant(p<0.05). However, no statistical significance exists in inter-group differences(p>0.05). Postoperative Cobb angles and intervertebral height of patients in both groups are considerably bettered compared with those before the operation. Their differences show statistical significance(p<0.05), while inter-group differences are proved to be not statistically significant(p>0.05). Applying a 3D-printed ACT titanium trabecular intervertebral fusion cage or PEEK cage in PLIF has the potential to improve clinical symptoms of patients with degenerative lumbar diseases, and restore the Cobb angle and intervertebral height. 3D-printed ACT titanium trabecular intervertebral fusion cage can accelerate intervertebral fusion without increasing operation related complications.

Double-protein-loaded 3D-printed polyetheretherketone cage for promoting interbody fusion via osteogenic differentiation

Intervertebral disc degeneration (IDD) is a common condition characterized by age-related wear and tear of the spine. In advanced stages or severe cases of IDD, surgical treatment involving the implantation of an interbody cage is often the primary treatment approach. Polyetheretherketone (PEEK) has been widely used in orthopedic and spinal implants due to its remarkable mechanical properties, biocompatibility, and corrosion resistance. However, when used in interbody cages, PEEK exhibits poor processability and biological inertness, which are significant disadvantages that need to be addressed. In this work, we first fabricated the PEEK cage via the fused deposition modeling (FDM) method. To improve its fusion effect, bone morphogenetic protein 2 (BMP2) was loaded onto sulfonated PEEK and sealed with gelatin/chitosan (Gel/Chi) multilayer films. Substance P was then grafted on the surface with a Schiff base. When the cage is implanted, substance P is released first, recruiting bone marrow-mesenchymal stem cells (MSCs) to the implant surface. Subsequently, upon degradation of the Gel/Chi multilayer films, BMP2 is slowly released and promotes osteogenic differentiation of MSCs. In vivo results revealed that the double-protein-loaded PEEK cage exhibited remarkable fusion effects. This work provides a novel approach for the design and fabrication of a PEEK intervertebral fusion device with an excellent fusion effect.

Preoperative planning of craniectomy and reconstruction using three-dimension-printed cranioplasty for treatment of calvarial lesion.

Common calvarial lesions include fibrous dysplasia (FD), intraosseous meningioma, osteoma, Langerhans cell histiocytosis (LCH), intraosseous hemangioma, dermoid and epidermoid cyst, and malignancy. Surgical removal with removal of the involved skull is the choice of treatment for these lesions. Previously, the skull defect was repaired using allograft, and alloplastic materials have been replaced with newer polyetheretherketone (PEEK) material, which is more resistant, biocompatible, and can be 3-dimension (3D)--printed. High-resolution 3D printing uses very fine extruders to put materials in fine layers to recreate patients' anatomy authentically, which gives superior cosmetic outcomes. Our objectives were preoperative planning of craniectomy and reconstruction for calvarial lesions and reconstruction of skull defects using 3D-printed cranioplasty with PEEK materials. In this series, we describe 11 cases in which skull lesions were removed and reconstructed in the same sitting using a 3D-printed PEEK implant designed preoperatively using high-resolution computer tomography. All the cases were done in the neurosurgery department of Bangabandhu Sheikh Mujib Medical University from 2021 to 2023. Patients were followed up for 6 months after surgery. Regarding 11 cases, six cases were FD, three cases were intraosseous meningioma, one case was intraosseous hemangioma, and one case was LCH. Average lesion size were 12.73-5.77 cm. Cranioplasty was done with PEEK material. Minor complications were treated conservatively. Seroma, postoperative fever, and nausea were among these. The human bone-like biocompatibility and resistance to physical forces leads to more frequent use of PEEK, which enables to repair of complex craniofacial defects with better cosmesis. Despite some limitations, the PEEK cranioplasty implant continued to thrive and showed its promise to be an excellent material. Further, research and investment should be put into developing the technique.

The effect of thermomechanical aging on the fracture resistance of additively and subtractively manufactured polyetheretherketone abutments

ObjectivesTo evaluate the fracture resistance (FR) of polyetheretherketone (PEEK) abutments produced by additive and subtractive methods compared to milled zirconia abutments. MethodsCustom abutments were designed on Ti-base abutments and produced from three different materials, namely additively manufactured PEEK (PEEK-AM), subtractively manufactured PEEK (PEEK-SM), and zirconia (N = 60). PEEK-AM abutments were printed using PEEK filaments (VESTAKEEP®i4 3DF-T, Evonik Industries AG) on a M150 Medical 3D Printer (ORION AM) by fused filament fabrication (FFF). All surface treatments were carried out according to the manufacturer's instructions. All abutments were cemented on Ti-bases with hybrid abutment cement and then restored with milled zirconia crowns. Each subgroup was divided into non-aged and aged subgroups (n = 10). The aged groups were subjected to thermomechanical aging (49 N, 5–55 °C, 1.2 million cycles). FR tests were performed by using an universal testing machine. Data were statistically analyzed with one-way and two-way ANOVA and t-test. ResultsThe survival rate of the specimens after aging was determined as 100%. It was found that both the material and aging had a significant effect on the FR (p<.001). There was a statistical difference among the fracture values of the groups (p<.001). In both the aged and non-aged groups, PEEK-AM showed the statistically lowest FR, while the highest FR was seen in the zirconia group, which was significantly higher than the PEEK-SM (p<.001). ConclusionHybrid abutments were successfully manufactured, and extrusion-based processed PEEK seems to be a good alternative to subtractive processed PEEK. However, since subtractive manufacturing still appears to be superior, further developments in additive manufacturing are needed to further improve the quality of 3D-printed PEEK parts, especially in terms of accuracy and bonding between adjacent layers. Clinical SignificanceAdditively manufactured PEEK abutments have the potential to be an alternative for implant-supported restorations in the posterior region.

Analysis of the Mechanical and Physical Behaviors of 3D-Printed PEEK Structures under Different Parameters

In this study, the mechanical and physical properties of polyetheretherketone (PEEK) material produced through three-dimensional (3D) printing under different production parameters were investigated. For this purpose, the results obtained by applying heat treatment to the produced samples were examined. Comparisons based on mechanical properties were supported by 3D surface profiles and XRD analyses. According to the obtained results, low nozzle diameter and high printing temperature led to an increase of up to 8% in the elastic modulus and up to 33% in tensile strength of the samples. The heat treatment applied in the study increased tensile strength by up to 8% and elastic modulus by up to 9% in samples produced with a low-diameter nozzle. In conclusion, this study aims to provide a dataset for 3D PEEK designs, intending to enhance the performance of PEEK materials that can be used in medical and industrial applications.

Investigating the Feasibility and Performance of Hybrid Overmolded UHMWPE 3D-Printed PEEK Structural Composites for Orthopedic Implant Applications: A Pilot Study.

Ultra-high-molecular-weight polyethylene (UHMWPE) components for orthopedic implants have historically been integrated into metal backings by direct-compression molding (DCM). However, metal backings are costly, stiffer than cortical bone, and may be associated with medical imaging distortion and metal release. Hybrid-manufactured DCM UHMWPE overmolded additively manufactured polyetheretherketone (PEEK) structural components could offer an alternative solution, but are yet to be explored. In this study, five different porous topologies (grid, triangular, honeycomb, octahedral, and gyroid) and three surface feature sizes (low, medium, and high) were implemented into the top surface of digital cylindrical specimens prior to being 3D printed in PEEK and then overmolded with UHMWPE. Separation forces were recorded as 1.97-3.86 kN, therefore matching and bettering the historical industry values (2-3 kN) recorded for DCM UHMWPE metal components. Infill topology affected failure mechanism (Type 1 or 2) and obtained separation forces, with shapes having greater sidewall numbers (honeycomb-60%) and interconnectivity (gyroid-30%) through their builds, tolerating higher transmitted forces. Surface feature size also had an impact on applied load, whereby those with low infill-%s generally recorded lower levels of performance vs. medium and high infill strategies. These preliminary findings suggest that hybrid-manufactured structural composites could replace metal backings and produce orthopedic implants with high-performing polymer-polymer interfaces.

Research Progress of 3D-Printed Polyetheretherketone in Implantable Medical Devices

Polyetheretherketone (PEEK) has emerged as a thermoplastic material of choice in the realm of implantable medical devices, owing to its high biocompatibility and exceptional mechanical strength. Despite its promise for custom-made medical devices, 3D-printed PEEK in orthopedics, trauma, and spinal implants has not yet achieved widespread application. This study outlines the properties of PEEK, 3D-printed PEEK-based composites, and their utilization in implantable medical devices, thereby fostering the development and regulation of next-generation medical devices.

Application of 3D‑printed porous titanium interbody fusion cage vs. polyether ether ketone interbody fusion cage in anterior cervical discectomy and fusion: A systematic review and meta‑analysis update.

The present study aimed to compare the differences between 3D-printed porous titanium and polyether ether ketone (PEEK) interbody fusion cages for anterior cervical discectomy and fusion (ACDF). Literature on the application of 3D-printed porous titanium and PEEK interbody fusion cages for ACDF was searched in the PubMed, Web of Science, Embase, China National Knowledge Infrastructure, Wanfang and VIP databases. A total of 1,181 articles were retrieved and 12 were finally included. The Cochrane bias risk assessment criteria and Newcastle-Ottawa scale were used for quality evaluation and Review Manager 5.4 was used for data analysis. The 3D cage group was superior to the PEEK cage group in terms of operative time [mean difference (MD): -7.68; 95% confidence interval (CI): -11.08, -4.29; P<0.00001], intraoperative blood loss (MD: -6.17; 95%CI: -10.56, -1.78; P=0.006), hospitalization time (MD: -0.57; 95%CI: -0.86, -0.28: P=0.0001), postoperative complications [odds ratio (OR): 0.35; 95%CI: 0.15, 0.80; P=0.01], C2-7 Cobb angle (MD: 2.85; 95%CI: 1.45, 4.24; P<0.0001), intervertebral space height (MD: 1.20; 95%CI: 0.54, 1.87; P=0.0004), Japanese Orthopaedic Association Assessment of Treatment (MD: 0.69; 95%CI: 0.24, 1.15; P=0.003) and visual analogue scale score (MD: -0.43; 95%CI: -0.78, -0.07; P=0.02). The difference was statistically significant, while there was no significant difference between the two groups in terms of fusion rate (OR: 1.74; 95%CI: 0.71, 4.27; P=0.23). The use of 3D-printed porous titanium interbody fusion cage in ACDF has the advantages of short operation time, less bleeding loss, shorter hospitalization time and fewer postoperative complications. It can better maintain the cervical curvature and intervertebral height, relieve pain and accelerate postoperative functional recovery.

Comprehensive analysis of fused deposition modeling process conditions for enhancing mechanical properties and surface quality of 3D-Printed poly-ether-ether-ketone

Fused deposition modeling (FDM) technology is a convenient manufacturing approach for poly-ether-ether-ketone (PEEK) components. In this study, a comprehensive study of the influence of FDM process parameters on the mechanical property and surface quality of 3D-printed PEEK printed with different directions was carried out. The results show that crystallinity of PEEK materials and the pores/gaps between the printing filaments jointly affect the mechanical properties and surface quality of PEEK structural parts. Then, material-structure-property linkage mechanism was revealed. Through the research conducted, crucial processing parameters to enhance the mechanical properties and surface quality of PEEK samples was determined. High tensile strength (91.75 MPa, which was close to the performance of injection molded components) and surface quality (Ra 7.9 μm) was obtained by regulation the nozzle temperature and annealing temperature to improve the crystallinity. Meanwhile, tensile strength of z-Sample was increased from 7.36 MPa to 18.30 MPa (with an increase of 148.64%). High Young's modulus (3.09 GPa) and large plastic strain (exceed 13.91%) was achieved by regulation the nozzle temperature and printing speed to reduce the porosity between PEEK filaments.

Point-of-Care 3-Dimensional-Printed Polyetheretherketone Customized Implants for Cranioplastic Surgery of Large Skull Defects.

3-Dimensional (3D) printing has become a common tool to aid implant molding for cranioplastic surgery of large skull defects. Until now, 3D printing of cranial implants itself has not been used, mainly because of medicolegal concerns. With a 3D printer developed for printing medical applications and with implant-grade polyetheretherketone (PEEK) filament available, we established a workflow (in compliance with medical device regulations) to 3D print cranial implants for cranioplastic surgery directly at the point of care (POC). Here, we describe the implementation of 3D printing these PEEK implants for cranioplastic surgery at our academic hospital. A thorough design and 3D printing process, in accordance with local medical device regulations, was developed. Implants are digitally designed based upon pre- and post-craniectomy cranial computed tomography scans by trained 3D printing experts from the department of medical engineering at our institution. Implants are then produced on a medical 3D printer with implant-grade PEEK filament using the fused filament fabrication process. After postprocessing and steam sterilization, implantation for reconstruction of the skull can be performed. Cranioplastic surgery with a 3D-printed PEEK implant was performed at our institution in a patient with a large frontotemporoparietal skull defect after traumatic brain injury with consecutive decompressive craniectomy. No intra- or post-operative complications occurred. Postoperative cranial computed tomography scans showed perfect reconstruction of precraniectomy skull shape. The aesthetic result was promising and satisfactory to the patient. This novel 3D printing workflow enables the production of patient-specific cranial implants from PEEK, to reconstruct large skull defects directly at the POC in accordance with the European Medical Device Regulation. This marks an unprecedented technological and legal advancement, enabling the hospital infrastructure not only to deliver the cranioplastic surgery itself, but also additive manufacturing of the implant directly at the POC.

Exploring the mechanical strength, antimicrobial performance, and bioactivity of 3D-printed silicon nitride-PEEK composites in cervical spinal cages

&amp;nbsp;In this study, our goal was to assess the suitability of a polyether-ether-ketone (PEEK) and silicon nitride (Si3N4) polymer composite for antimicrobial three-dimensional (3D)-printed cervical cages. Generic cage designs (PEEK and 15 vol.% Si3N4-PEEK) were 3D-printed, including solid and porous cage designs. Cages were tested in static compression, compression shear, and torsion per ASTM F2077. For antibacterial testing, virgin and composite filament samples were inoculated with Staphylococcus epidermidis and Escherichia coli. In vitro cell testing was conducted using MC3T3-E1 mouse preosteoblasts, where cell proliferation, cumulative mineralization, and osteogenic activity were measured. The 3D-printed PEEK and Si3N4-PEEK cages exhibited adequate mechanical strength for all designs, exceeding 14.7 kN in compression and 6.9 kN in compression shear. Si3N4-PEEK exhibited significantly lower bacterial adhesion levels, with a 93.9% reduction (1.21 log), and enhanced cell proliferation when compared to PEEK. Si3N4-PEEK would allow for custom fabrication of 3D-printed spinal implants that reduce the risk of infection compared to unfilled PEEK or metallic alloys. &amp;nbsp;