3D-printed Polyetheretherketone Research Articles

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;

Sand casting-inspired surface modification of 3D-printed porous polyetheretherketone scaffolds for enhancing osteogenesis

3D-printed polyetheretherketone (PEEK) scaffolds are developed as novel bone substitutes, however, their bioinert surface hinders osteogenesis and modifying PEEK scaffolds without blocking their inter-connected porous structure is challenged. In this study, 45S5 bioactive glasses (BG) were homogeneously coated on PEEK scaffolds inspired by traditional sand-casting. The structure of PEEK scaffolds was preserved under shaping effect of BG fillers. Modulus, coating yield and hydrophilicity of scaffolds after different thermal treatment time were comparatively investigated. Excellent hydroxyapatite-forming ability of BG-coated scaffolds was confirmed by mineralization study. In-vitro assessments, BG-coated scaffolds cultured with MC3T3-E1 cells presented potential as bone implants with excellent cytocompatibility and osteogenic properties. Following similar coating strategy, conductive particles, multi-component particles and template particles were also coated on PEEK surface. The proposed methodology highlights a useful approach towards producing tunable biomedical coatings and microstructure on porous PEEK scaffolds for bone tissue engineering.

Management of severe defects of humerus in combat patients injured in Russo-Ukrainian war

IntroductionRusso-Ukrainian war is associated with application of high-energy weapon, causing severe multifragmental injuries to the bones an associating with severe bone defects.The aim of the study was to evaluate various methods to treat combat patients with severe defects of humerus and to demonstrate the experience of orthopedic war surgeons in managing gunshot injuries to the humerus defects in the ongoing war. Patients and methodsA 24 patients were active-duty military personnel of Armed Forces of Ukraine. These patients were diagnosed with severe humerus defects due to gunshot injury in battlefield zone in various areas of Ukraine. Data was collected within period between February, 24th 2022 till January, 01st 2023. The following approaches were applied to replace bone defect: preoperative 3D printing with polyetheretherketone (PEEK) as orthobiological material; closed reduction, percutaneous lag screw and Ilizarov external fixation; vascularized fibula grafting. ResultsData analyses of the segmental defects of humerus showed 5 cm defect in 3 (13 %) patients, from 5 to 10 cm in 4 (17 %) patients, over 10 cm in 17 (71 %) patients. Analyses were performed in these 17 (71 %) patients, showing 5 patients treated with 3D-printed PEEK implants, 6 patients with vascular-pedicle graft of fibula, 6 patients with closed reduction, percutaneous lag screw, Ilizarov external fixation. Osteomyelitis was diagnosed in one case (20 %) after the use of PEEK implants, requiring to remove both PEEK implant and metal implants followed by application of the antibiotic joint spacers and Ex-Fix fragments of the humerus. In our opinion, the osteomyelitis happened due to inadequate debridement of the wound and non-compliance with the conversion criteria (replacement of the fixation method). The mean length of hospital stay was 5.5 months for patients treated with 3D-printed PEEK implants. ConclusionsClosed reduction, percutaneous lag screw and Ilizarov external fixation as well as vascularized fibula grafting are associated with good outcomes in management of the patients with severe humerus defect due to gunshot injury. 3D printing and PEEK implants could also be considered for the reconstructions of the humerus multifragmental fractures with a bone defect over 10 cm associated with gunshot injury due to high-energy weapon in the war settings.

High-Cycle Fatigue Behaviour of Polyetheretherketone (PEEK) Produced by Additive Manufacturing.

Polyetheretherketone (PEEK) is the leading high-performance thermoplastic biomaterial that can be processed through material extrusion (ME) additive manufacturing (AM), also known as three-dimensional (3D) printing, for patient-specific load-bearing implant manufacture. Considering the importance of cyclic loading for load-bearing implant design, this work addresses the high-cycle fatigue behaviour of 3D-printed PEEK. In this work, printed PEEK specimens are cyclically loaded under stress-controlled tension-tension using different stress levels between 75% and 95% of printed PEEK's tensile strength. The experimental results are used to document 3D-printed PEEK's fatigue behaviour using Basquin's power law, which was compared with previous fatigue research on bulk PEEK and other 3D-printing materials. As a pioneering study on its fatigue behaviour, the results from this work show that 3D-printed PEEK exhibits an above-average fatigue strength of 65 MPa, corresponding to about 75% of its tensile strength. Fracture surface analysis suggests that a transition can occur from ductile to brittle fracture with maximum stresses between 85% and 95% of the tensile strength. Evidence of crack propagation features on fracture surfaces under scanning electron microscope (SEM) observation suggests crack initiation in void defects created by printing deposition that propagates longitudinally through line bonding interfaces along layers. Considering this, 3D-printed PEEK's fatigue behaviour can be strongly related to printing conditions. Further research on the fatigue behaviour of 3D-printed PEEK is necessary to support its use in load-bearing implant applications.

Experimental Analysis of Crystallinity and Mechanical Properties for Fused Filament Printed Polyetherketone Composites

The objective of this article is to examine the impacts of molybdenum disulphide (MoS2) and graphite-filled (Gr) polyetheretherketone (PEEK) composites that have been fabricated through 3D printing on their mechanical properties and crystallinity. Seven samples and thirty-five dog bones were produced using different filament strands to conduct the analysis. Before extrusion into filaments, the solid lubricants, MoS2, and graphite were uniformly dispersed within the PEEK through mechanical blending. At a concentration of 10 wt.%, the PEEK/MoS2 composites exhibited the highest tensile strength, measuring approximately 104 MPa, while the PEEK/Gr composites displayed the lowest tensile strength at the same concentration, approximately 36 MPa. In addition, the PEEK/MoS2 composites demonstrated better elongation, approximately 4.7%, compared to the PEEK/Gr composites, which exhibited approximately 2.3% elongation. X-ray diffraction (XRD) data revealed that neither MoS2 nor graphite significantly interacted with the PEEK matrix. The degree of crystallinity, as determined by density matrices, indicated that the printed PEEK composites possessed a higher level of crystallinity, approximately 62% at a concentration of 5 wt.%, than the calculated values. This suggests that the filament-making and 3D printing processes had an annealing effect. The significance of solid lubricant content and dispersion in shaping the mechanical properties and crystal formation of 3D-printed PEEK composites is emphasized in this study. Furthermore, this research provides valuable insights for optimizing PEEK-based materials for various applications.

Determining the effect of porosities on the hydrogen adsorption capacity of 3D printed PEEK

In this investigation, as one of the most common polymer-based materials, polyether-ether-ketone (PEEK) was chosen to study its hydrogen adsorption capacity. The shape and size of porosities control the specific surface area and possible sites of hydrogen adsorption. Therefore, the FDM 3D printing method was utilized to fabricate the PEEK sample with different porosity sizes, and the effect of variation of the process parameters (nozzle temperature and nozzle speed) on the shape and size of porosities and finally, the hydrogen adsorption capacity was evaluated. The effect of the variation of the nozzle temperature on the heat distribution was simulated using COMSOL Multiphysics. The results of the heat temperature distribution exhibited that the shape of the porosities will be differed due to the solidification shrinkage caused by the temperature gradients in the middle areas of the 3D-printed PEEK samples, which was subsequently confirmed by optical microscopy and X-ray Computed Tomography (XCT). Porosities can be classified into three main groups including mesopores, mesopores and macropores. Additionally, 3D printed parts have the porous structure and by designing a porous structure by CAD software, the formation of the macropores and subsequently meso-and micropores is passivated, which can be detected through the XCT results. Consequently, these pores increased the surface area and provide more site for hydrogen adsorption. XCT was carried out, and the results showed the formation of the closed pores, which was decreased by increasing the nozzle temperature due to the presence of the melted filament from 0.64 to 0.19%. The hydrogen adsorption capacity was studied through electrochemical analysis methods including cyclic voltammetry, charge/discharge, and electrochemical impedance spectroscopy. Results showed that the sample was printed with a nozzle temperature of 375 °C and nozzle speed of 30 mm s−1, illustrating the highest electrochemical hydrogen adsorption capacity of 2.66 mAh.g−1, which can be related to the activation of the capillary force and new available sites in the interface of the electrolyte and 3D-printed electrode.

Computational assessment of effect of porosity on thermal conductivity of 3D-printed PEEK/carbon-fiber composite

The three-dimensional (3D) printing of polymer matrix composites has attracted considerable attention. However, the addition of filler materials to the extruded polymer matrix results in inner voids within the beads along with larger voids, called intervoids, which are generated between the beads during the 3D printing process. These voids degrade the thermal transport properties of 3D-printed polyether ether ketone (PEEK) and PEEK/carbon-fiber composites. The effects of these pores (i.e., their number, size, and location) on the thermal conductivity of 3D-printed PEEK and a PEEK/carbon-fiber composite were investigated using a multiscale finite element approach. The presence of the carbon fibers mitigated the effect of the pores on the thermal conductivity of the PEEK/carbon-fiber composite, particularly along the longitudinal direction. Moreover, the inner voids had a dominant effect on the PEEK and PEEK/carbon-fiber composite. Finally, the orientation of the intervoids had no effect on the thermal conductivity of the printed materials.

Feasibility of 3D-Printed Locking Compression Plates with Polyether Ether Ketone (PEEK) in Tibial Comminuted Diaphyseal Fractures.

The applicability of a polyether ether ketone locking compression plate (PEEK LCP) fabricated using FDM (fused deposition modeling)-based 3D printing to treat actual patients was studied. Three different tests-bending, axial compression, and axial torsion-were conducted on tibial non-osteoporotic comminuted diaphyseal fracture samples fixed with the commercial titanium alloy LCP and 3D-printed PEEK LCP. Comparing the outcomes of these tests revealed that the commercial titanium alloy LCP underwent plastic deformation in the bending and axial torsion tests, though the LCP did not fail even when an external force greater than the maximum allowable load of the tibia fixture of the LCP was applied. Elastic deformation occurred in the 3D-printed PEEK LCP in the bending and axial torsion tests. However, deformation occurred even under a small external force, and its stiffness was 10% compared to commercial titanium alloy LCP. Thus, 3D-printed PEEK LCP can be applied to the fracture conditions in non-weight-bearing regions. The experimental results reveal detailed insights into the treatment of actual patients by considering the stiffness and high toughness of 3D-printed PEEK LCP.

A comprehensive mechanical characterization of as-printed and saliva soaked 3D printed PEEK specimens for low-cost dental implant applications

Dental implants play an important role in the reconstruction of the lost tooth. The implant materials and manufacturing techniques are of significant importance in the performance of the implants. Conventional dental implant materials such as titanium and zirconia exhibit many limitations such as allergies, peri-implant bone loss, and implant fractures. Implant fractures are caused due to stress shielding arising from the significant difference in mechanical properties between the implant and jawbone. However, polymeric materials can overcome the limitations of metallic implant materials. In this work, Polyether ether ketone (PEEK) specimens are manufactured using the fused deposition molding (FDM) technique, and the effect of printing parameters on its mechanical properties are investigated for dental implant applications. Three different raster angles, (0°/0°), (45°/−45°), and (90°/90°), were considered, and an array of mechanical characterizations are performed on the printed specimens to find tensile, compression, flexural, hardness, and saliva absorption properties for as-printed and saliva soaked conditions. 3D-printed PEEK specimens with a (45°/−45°) raster angle displayed a superior mechanical properties compared to other raster angle specimens. Results showed that 3D printed PEEK exhibits similar properties to natural human tooth enamel, while extruded PEEK exhibits characteristics similar to natural dentin and cortical bone. The 3D printed PEEK crown's potential to withstand compressive loads during biting (∼50 N) was also evaluated and found that the PEEK has adequate mechanical properties to be a better low-cost implant material than titanium and zirconium.

Customed 3D-printed Polyetheretherketone (PEEK) Implant for Secondary Salvage Reconstruction of Mandibular Defects: Case Report and Literature Review.

Given the insufficient height of single-barrel fibula and inadequate bone volume of double-barrel vascularized fibula in mandibular reconstruction, it is a better choice to combine the upper full-thickness vascularized fibula with the lower half-thickness nonvascularized fibula. However, the nonvascularized fibula may fail due to complications, affecting the facial shape and occlusal function. Polyetheretherketone is a thermoplastic polymer used for bone defect reconstruction due to its good mechanical properties and biocompatibility. This case report mainly presents a secondary salvage reconstruction of the mandible by using customed 3-dimensional-printing polyetheretherketone, which restored the continuity and symmetry of the mandible, improved the patient's facial shape, and restored functional occlusion through dental implants. After a 28-month follow-up, no complications occurred, and the patient was satisfied with the final restoration.