Polyetheretherketone Material Research Articles

Effects of various laser applications on surface roughness and bond strength to veneering composites of polyether ether ketone (PEEK) and polyether ketone ketone (PEKK) materials.

The aim of this study was to investigate the bond strength between PEEK/PEKK and composite resins after various laser treatments and to compare the effectiveness of lasers on these polymers. 130 disc-shaped PEEK and PEKK blocks were obtained (10mm diameter-4mm height). One sample from each group (10 in total) was selected for scanning electron microscopy (SEM) analysis. The samples were randomly divided into 5 different surface treatment groups for each material (PEEK and PEKK): Er: YAG laser, Nd: YAG laser, diode laser, femtosecond laser and control (no surface treatment) (n = 12). Baseline and post-treatment surface roughness measurements were performed using a profilometer. The composite resin was bonded and SBS was measured. Comparisons among the groups were conducted via Kruskal-Wallis, one-way ANOVA; Tukey and Dunn tests were used as a post hoc test (p ≤ 0.05). All lasers significantly increased the roughness values of the PEEK and PEKK samples. In terms of shear bond strength; the Er: YAG and femtosecond laser groups had the highest values and the Nd: YAG, diode and control groups had the lowest values of the PEEK samples (p ≤ 0.05). The control group had the highest bond strength values and the femtosecond group had the lowest values for PEKK samples (p ≤ 0.05). All laser treatments increased the surface roughness of the PEEK and PEKK. Lasers increased the bond strength of PEEK to the veneering composite resin and decreased the bond strength values of PEKK. This shows that lasers behave differently in PEEK and PEKK materials.

Ultra-high-rate Manufacturing of Thermoplastic Window Plug using Hybrid Overmolding

Highly loaded complex parts are machined from a solid block of metal by removing material through cutting, boring, drilling, and grinding to obtain the three-dimensional shape. Most cases, this involves removing as much as 80 percent of the material from a billet, which is time-consuming and inefficient considering the cost of the materials. Alternatively, these complex parts can be manufactured using hybrid overmolding process which involves injecting plastics over a reinforced substrate with continuous fiber-reinforcement eliminating subtractive machining or joining of multiple parts. The substrate is typically heated using an infrared (IR) oven and preformed over a solid mold to a three-dimensional shape using thermoforming. Injection overmolding material can also be reinforced with discontinuous fibers based on the design requirements. Both thermoforming and injection molding are matured automotive ultra-high-rate manufacturing processes. Adopting these technologies to aerospace requires advanced aerospace-grade thermoplastic material systems and developing the hybrid overmolding process that combines both thermoforming and injection molding processes. Material compatibility is one of the key enablers for the fusion across the overmolded interfaces. To demonstrate the overmolding technology for an aerospace application, Victrex AE250 low-melt polyaryletherketone (LM-PAEK) system reinforced with AS4 fibers and a 30% carbon fiber-reinforced polyetheretherketone (PEEK) were used to overmold aircraft window plugs to be used for cargo conversion of passenger aircraft. The fully automated overmolding process was demonstrated using KraussMaffei multi-robotic thermoforming and injection molding system. Thermal and mechanical test evaluations were employed to assess the material compatibility and overall part quality. Photomicrographs and flexure tests conducted on test samples extracted from the window plugs indicated satisfactory fusion across the overmolded interface and optimized holding of PEEK materials.

Study of thermal stress deformation in hybrid 3D printing and milling process of PEEK material

Hybrid manufacturing can enable rapid production of personalized artificial bones that are made of Polyether-ether-ketone (PEEK) by integrating 3D printing and milling. A main challenge, however, is the thermal stress deformation that arises from the fused deposition process, leading to warping and shrinkage. As a result, the fabrication accuracy is significantly diminished. This work aims to address this challenge by investigating the thermal stress deformation behavior of PEEK in hybrid manufacturing. The main contributions of this work, therefore, include the development of a model for this thermal deformation behavior, and the identification of key parameters such as cross-section length ( Ls), printed layer thickness ( Lh), and current workpiece height ( He). Further, experiments are conducted based on response surface methodology (RSM) to explore the relationships between temperature variation rate (Δ T), end surface height difference (Δ S), and length shrinkage rate (Δ L) with critical hybrid processing parameters. Optimal parameter combinations are then identified. Our experiments demonstrate that the proposed methods effectively reduce the effects of warping and shrinkage.

Characterize the high-temperature steady-state rheological behavior and Arrhenius activation of PEEK via strain rate jump tensile tests

Polyetheretherketone (PEEK) is a high-performance thermoplastic polymer with diverse industrial applications, such as aerospace, automotive, electronics, and medical devices. However, systematic research on its high-temperature rheological characteristics is inadequate. In this study, strain rate jump tensile tests were introduced to examine the steady-state rheology phenomena and strain rate sensitivity of PEEK at four different temperatures and nine different strain rates. Theoretical analysis based on the free volume theory and the Arrhenius law was also carried out to further analyze the transition of PEEK from Newtonian flow to non-Newtonian flow. Results indicate that PEEK materials exhibit a transition from Newtonian flow to non-Newtonian flow similar to metal materials at high temperatures. The transition point from Newtonian flow to non-Newtonian flow is marked by the emergence of steady-state rheology and its characteristic stress. Theoretical analysis demonstrates that the transition of PEEK is in accordance with the Arrhenius low. Moreover, its apparent activation energy (1.42 eV) is significantly lower than that of metal materials (5.28 eV), indicating a lower energy barrier and an easier transition. The strain rate sensitivity index correlates negatively with rising temperatures, especially at lower rates. This study enhances understanding of PEEK's rheological characteristics at high temperatures, aiding the development and application of high-performance thermoplastic materials.

Evaluation of Color and Translucency Changes of PEEK Material Veneered with Single-Shade Composite Resins

Aim: The aim of this study was to evaluate the color and translucency changes of single-shade composites used in veneering polyetheretherketone (PEEK) material after aging. Materials and Methods: 3 single-shade composites with different chemical structures and 1 conventional composite resin were applied on the PEEK material with a thickness of 2 mm (N=40, n=10). L, a, and b color coordinates of each specimen were measured three times with a spectrophotometer on a black, gray, and white background from the center of the specimen, and the average of these measurements was recorded. The specimens were subjected to 5000 cycles of thermal aging at 5-55°C. After aging, color measurements were repeated. Color changes (ΔE00) and translucency parameters (ΔTP00) of composite resin specimens were determined before and after aging using CIEDE 2000 color formulas. The data obtained were analyzed by one-way analysis of variance and Tukey HSD test (p<0.05). Results: As a result of the study, the color change of all composite resin materials was found to be below the clinically acceptable limit (ΔE = 1.8). The lowest color change was observed in the traditional composite group, and a statistically significant difference was found between the other groups (p<0.05). The translucency change of single-shade composite materials was found to be statistically lower than that of conventional composite resin (p<0.05). Conclusion: This study's results show that single-shade composite resins can be used as an optical alternative to traditional composites in direct veneering of the PEEK material.

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.

In vitro Examination of the Bond Strength of PEEK and PEKK Materials Used as Substructure Materials with the Superstructure Composite before and after Artificial Aging and Examination of Scanning Electron Microscope Images

Abstract Objective This study aims to evaluate the bond strength of polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) materials when used as substructures with composite superstructures, before and after artificial aging. Surface treatments, including sanding and sandblasting, were examined to determine their impact on bond strength and surface topography. Materials and Methods Sixty samples, divided equally between PEEK and PEKK, were prepared. Each group was further divided into three subgroups (n = 10): control, 10,000 thermal cycles, and 30,000 thermal cycles. The samples were subjected to surface treatments using 600-, 800-, and 1,200-grit silicon carbide wet sandpaper, followed by air abrasion with 110 µm alumina particles. Bond strength tests were conducted using an INSTRON-3345 universal testing machine, and failure types were analyzed under a stereomicroscope. Results Sandblasting with 110 µm aluminum oxide (Al2O3) significantly increased the bond strength of both PEEK and PEKK materials compared with sanding. PEEK samples treated with sandblasting showed the highest bond strength (mean = 1.296 MPa), while PEKK samples treated with sanding had the lowest (mean = 0.056 MPa). Thermal cycling reduced bond strength in both materials, with a more pronounced decrease observed in the 30,000 cycle groups. analysis of variance results indicated significant differences in bond strength based on the material, surface treatment, and the interaction between these factors. Conclusion Sandblasting with 110 µm Al2O3 is an effective method for enhancing the bond strength of PEEK and PEKK substructures with composite materials. These findings support the continued use of PEEK and PEKK polymers in dental applications, suggesting that appropriate surface treatments can significantly improve clinical outcomes.

Polyetheretherketone split post and core for restoration of multirooted molar with insufficient dental tissue remnants by digital techniques: a case report and 3-year follow up

BackgroundMulti-rooted teeth with extensive dental defects often face challenges in stability and biomechanical failure. High-performance polymer PEEK materials, with properties closer to dentin, show promise in reducing stress concentration and preserving tooth structure. This report aimed to explore the use of a highly retentive polyetheretherketone (PEEK) for manufacturing custom-made split post and core for the restoration of grossly destroyed endodontically treated molars.Clinical considerationsA 40-year-old female patient presented with complaints of loss of tooth substance in the posterior mandibular tooth. This case involved the digital design and fabrication of PEEK split post and core to restore multirooted molar with insufficient dental tissue remnants. The restorations were evaluated over a 3-year follow-up using the World Federation criteria (FDI). The restoration was clinically evaluated through intraoral examination, radiographic assessment, and subjective patient satisfaction, and was deemed clinically good according to FDI criteria.ConclusionThe outstanding mechanical properties of PEEK, coupled with the structure of the split post, provide an effective treatment option for weakened multirooted teeth. Simultaneously, the restoration configuration effectively addressed the challenge of varying postinsertion directions, and the interlocking mechanism between the primary and auxiliary posts enhanced the stability of the post and core.

Electromechanical coupling in polyetheretherketone through flexoelectricity

The electrical signals generated by an electromechanical coupling mechanism in biomaterials have significant potential applications in the field of biomedical engineering. For example, the piezoelectric- or flexoelectric-induced electrical signals in bone biomaterials play an important role in facilitating self-repair, remodeling, and reshaping processes. Polyetheretherketone (PEEK) has been found to possess excellent mechanical properties and biocompatibility with bone, making it an outstanding choice as an implantable polymer material. It is particularly important to investigate the electromechanical response performance of PEEK materials. In this study, we experimentally examine the flexoelectricity of PEEK and evaluate its effective out-of-plane direct and converse flexoelectric coefficients. Using the piezoresponse force microscopy module of atomic force microscopy, we observe a clear converse flexoelectric effect in a PEEK disk-shaped sample. The effective out-of-plane converse flexoelectric coefficient of the PEEK disk-shaped sample is about μ3333eff=0.21 ± 0.02 nN/V. The effective out-of-plane direct flexoelectric coefficient, determined through the bending experiment of a PEEK cantilever, is f3113eff = 17.61 nC/m, which is larger than that of polyvinylidene fluoride and is nearly two orders of magnitude superior over other biomaterials such as bone and hydroxyapatite. This indicates that PEEK materials have even greater potential for development and research in biomedical engineering applications such as intervertebral fusion, bone joint replacement, bone rehabilitation and regeneration, etc.

Clinical applications and improvement of resin bonding for PEEK in resin-bonded fixed dental prosthesis: A review

Resin-bonded fixed dental prostheses (RBFDPs) are a commonly used precision treatment, such as fixed dental prosthesis (FDP) and implant-supported dentures. Full crown preparation of vital teeth, which is required for traditional FDPs, may result in a risk of pulp reaction as a large portion of the coronal tooth structure must be removed. RBFDP has been recognized as a non-invasive or minimally invasive treatment modality for the replacement of single missing teeth. RBFDPs require much less tooth preparation than conventional FDPs. These dental treatments are restorative solutions used to cover missing teeth and achieve an aesthetic smile. The biomechanical rules, aesthetics, polishability, and bond strength have been emphasized in RBFDP treatments. Polyetheretherketone (PEEK) is one of the most widely used biomaterials in dentistry. The material, which stands out especially with its acceptable aesthetics, biocompatibility and modulus of elasticity close to dentin, has enabled it to be used in RBFDP treatments. Since PEEK is lighter than metal alloys, patients experience less discomfort and a feeling closer to natural teeth. Furthermore, the thermoplastic properties of PEEK are claimed to provide a precise fit, allowing the restoration to better integrate into the natural tooth structure. In addition, its ability to be customized using different modern manufacturing techniques is thought to offer dentists and patients a reliable option for successful long-term treatment. Our review is about the use of PEEK material as an alternative material in RBFDPs with low negative effects on periodontal tissues and their bonding with resins.

Tribological Properties of PEEK and Its Composite Material under Oil Lubrication

PEEK (Poly Ether Ether Ketone) is a high-performance thermoplastic polymer with excellent mechanical, thermal and chemical stability. PEEK has good performance, and is widely used in hydraulic motors. However, there are few studies on the friction and wear properties of materials under the condition of oil lubrication with wide application. The modification of PEEK and the expansion of its application have become a hot research topic in the industry. This study focuses on the modification of the design of PEEK and explores the friction and wear characteristics of self-lubricating materials under different modification schemes. Friction and wear samples were prepared using PEEK-modification pelletizing and injection-molding processes, followed by fixed-condition friction and wear tests. The tribological mechanisms and wear properties of the materials under different modification schemes were analyzed, leading to the identification of several sets of improved reinforced materials. Experimental results demonstrate that modified materials can enhance surface tribological performance, with the best modification effect observed at an SCF filling rate of 15%. The modified PEEK material can better meet the requirements of specific applications, such as high-temperature environments, chemically aggressive environments, or applications requiring high strength and wear resistance.

Effect of moisture content in polyether-ether-ketone (PEEK) filament on 3D printed parts

Polyether-ether-ketone (PEEK) is a recently commonly used high-performance thermoplastic material with high heat resistance, high chemical resistance, high water resistance, and high wear resistance. Polyether-ether-ketone products with complex structures manufactured through the 3D printing process of fused filament fabrication (FFF) are emerging in the medical field. However, similar to other plastics, PEEK materials are also hygroscopic. This may have an impact on 3D printed products. The effect of storage time of filament on 3D printed PEEK products under specific temperature and humidity conditions has not been further explored. This study is mainly to explore the moisture absorption of PEEK filament for different storage time and the effect of moisture absorption on the performance of 3D printed PEEK products. The correlation between storage time and moisture absorption is verified by experiment. It is found that moisture will affect the surface quality of PEEK products. In addition, the mechanical test results show that the increase in the amount of water absorbed leads to the decrease of material properties, such as tensile strength, density, and hardness. Therefore, it is recommended to store unused or leftover PEEK filaments under vacuum drying conditions. For PEEK filaments that are being printed, it should be ensured to replace them every less than 24 h.

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.

Friction and Wear Performance of a Hydraulic Motor Roller/Piston Pair Contact lined with the Self-Lubricating Bearing Bush Modified by PEEK

Poly Ether Ether Ketone (PEEK) is a kind of special engineering plastic with excellent properties such as high-temperature resistance, self-lubrication, wear resistance, and high mechanical strength. However, its blending or composite modification applications still face numerous challenges. The primary objective of this research was to evaluate the friction and wear performance of a three-layer self-lubricating bearing bush, which was made from a modified material containing short carbon fiber and Poly Ether Ether Ketone (SCF/PEEK). The bearing bush is used as a surface contact layer on the pistons of a hydraulic motor in the interface with the cam roller. The bearing bush was processed using a 15% SCF-modified PEEK material, and the friction and wear test was conducted using a self-built friction test machine. This study aimed to assess the frictional and wear characteristics of the SCF/PEEK-modified material in the bearing bush. The results show that as the experimental pressure rises from 15 MPa to 25 MPa, the friction coefficient of the SCF-modified bearing bush experiences a significant decrease from 0.420 to 0.296. Furthermore, the stability of the frictional morphology of carbon fibers indicates its effective adaptability to low speed and high load conditions.

Determination of “tribological performance working fields” for pure PEEK and PEEK composites under dry sliding conditions

Poly-ether-ether-ketone (PEEK) and PEEK composites are widely used polymers in many engineering applications where dry sliding is required. In this study, the influence of sliding velocity and applied load values on the friction and wear behavior of pure PEEK, 30 wt% glass fiber reinforced PEEK (PEEK-30GF), 30 wt% carbon fiber reinforced PEEK (PEEK-30CF) and 10 wt% carbon fiber+10 wt%graphite +10 wt%poly-tetra-fluoro-ethylene (PTFE) filled PEEK (ie. High (H) pressure (P) and velocity (V) resistant PEEK (PEEK-HPV)) composites rubbing against AISI 304 stainless steel disc was investigated. The experiments were carried out at room temperature under dry sliding conditions in a pin-on-disc wear rig. The applied loads ranged from 30 to 250 N, while the sliding velocities ranged from 1.0 to 4.0 m/s. At these load and velocity ranges, the friction coefficient-wear rate relationship of pure PEEK and composites was established and evaluated. In addition, the operating load-velocity limits of each material were determined and stated. The lowest coefficient of friction and wear rate were obtained in PEEK-HPV, PEEK-30CF, PEEK-30GF composites and pure PEEK polymer, respectively. In addition, it was observed that the coefficient of friction (CoF) decreased and the specific wear rate (SWR) increased with the increase in sliding velocity and applied load in all PEEK materials. The wear rate values of PEEK-HPV and PEEK-30%CF composites are in the range of 10−7 - 10−6 (mm3/Nm), while the wear rate values of pure PEEK and PEEK-30%GF are in the range of 10−6 - 10−5 (mm3/Nm). It was determined that carbon fiber, graphite and PTFE additives added to PEEK polymer as hybrid were very effective in reducing the wear rate of PEEK composite (PEEK-HPV). An adhesive wear mechanism was observed in PEEK-HPV and PEEK-30CF composites both at low load and velocity values and at high load and velocity values.

Retention and wear assessment of two different bar materials used in implant-retained mandibular overdenture

Abstract Aim To assess retention and wear of two different bar materials (cobalt chromium and poly ether-ether ketone) used in implant-retained mandibular overdenture subjected to chewing simulation Robota during 1 year of functional simulation. Patients and methods This study is a comparative laboratory study which was carried out on 14 models of implant-retained mandibular overdenture, for each model two implants were inserted. The 14 models were divided equally into two equal groups: group A (overdenture constructed over two implant analogs with bar attachment and clip made from cobalt chromium material), and group B (overdenture constructed over two implant analogs with bar attachment and clip made from poly ether-ether ketone material). Drilling of the models was done using milling machine and each model received two implant analogs inserted 11 mm from midline at canine region. The overdentures were constructed in the usual manners and the teeth were set in lingualized occlusion. The mandibular overdentures were subjected to 150 000 chewing cycles using Robota chewing simulator and 1080 insertion-removal cycles. Retention of the samples was measured by the universal testing machine and wear observed under USB digital microscope both of which were done at the beginning of the study and after 3, 6, 9, and 12 months. Results The retention force for group A decreased significantly from baseline 43.43 ± 5.25 to 35.56 ± 8.30 after 3 months of cyclic loading, with similar reductions after 6, 9, and 12 months. Group B also showed reductions from baseline 26.75 ± 2.32 to 21.29 ± 6.74 after 3 months, and similar patterns over time. Group A had no statistically significant wear changes after cyclic loading, with a baseline mean of 0.2904 ± 0.0008, changing to 0.2913 ± 0.0008 after 3 months, while group B showed similar nonsignificant changes. There were no statistically significant differences in wear between both groups at any time point. Conclusion Retentive forces decrease with increasing cyclic loading. However, both materials displayed acceptable retentive values. Wear values were nonsignificant between two studied groups.

Numerical Analysis on Frictional Heat Effect in Polyether-Ether-Ketone (PEEK)/Steel Pair by using OpenFOAM Model

The PEEK material has been applied to a sliding bearing system in a power plant system because of its high mechanical durability. In the solid friction of the PEEK materials, the frictional heat becomes the important factor because the temperature increase due to the frictional heat causes the rapid increase of the frictional coefficient of the specimen. To maintain the low frictional coefficient of the PEEK materials, an effective cooling method for the PEEK materials needs to be developed. In this study, the passive cooling method, which attaches the heat sink to the PEEK materials, was suggested. For evaluating the suggested cooling method of the PEEK materials, the calculation model adopting OpenFOAM, which is open-source software, has been developed. Adopting some functions and libraries of OpenFOAM, the frictional heat, heat resistance, and heat transfer coefficient on the heat sink were modelled. The sliding bearing experiment was conducted and time variation of the temperature and friction coefficient in the ring specimen were measured. The temperature variation in the ring specimen was compared with the calculation result. From the numerical calculation results, the developed calculation model could simulate the temperature-time variation of the ring obtained in the experiment, when the variation of the frictional coefficient, heat resistance, and heat transfer coefficient was modelled appropriately. Based on the friction and wear test results, by applying a heat dissipation mechanism to the ring test piece, the calorific value of the PEEK material can be reduced, and it is stable. It was suggested that the friction was maintained.

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.

Effect of cement volume on biomechanical response of a spine segment treated with a PEEK polymer implant: a finite element comparative study with vertebroplasty.

In the current study, a 3D finite element study was performed to investigate the biomechanical response of an osteoporotic spine segment treated with a novel transpedicular implant (V-STRUT©, Hyprevention, France) made of PEEK (polyetheretherketone) material combined with either injections of 2, 3, 4, 5 and 6 cc of cement. The objective was to assess numerically the biomechanical performance of the implant in combination with different doses of the injected bone cement and to compare its performance with the gold standard vertebroplasty (VP) technique. A female (69yo) was selected and a 3D finite element model of an osteoporotic spine segment was built based on a Computed Tomography (CT) scan performed from T12 to L2 with corresponding intervertebral discs and ligaments. A heterogeneous distribution of bone material properties was assigned to the bone using grey scale levels. Bilateral ellipsoid geometries of the inserted cement were retained for the V-STRUT and VP models based on experimental observation performed on different patients treated with the V-STRUT device. The current study demonstrated an optimal dose of 4 cc of bilaterally injected cement for the V-STRUT and VP techniques to restore the treated segment and confirmed that the V-STRUT device in combination with bone cement is superior to VP alone in establishing the normal stiffness and in reducing the applied stress to the immediately adjacent vertebral levels.

Evaluation of stress distribution of different marginal designs on PEEK and PEKK substructure materials, cortical and cancellous Bone:A finite element analysis

High-performance polymers are used in different fixed prosthesis treatments due to their many advantages such as biocompatibility, shock absorption ability, high fracture resistance. The effects of marginal design on the forces on high-performance polymers are unknown. This study aimed was to investigate the stress distribution of different marginal designs on Polyetheretherketone (PEEK) and Polyetherketoneketone (PEKK) substructure materials, cortical bone and cancellous bone by finite element analysis. A first maxillary molar tooth was modeled in 3D using the "3D Complex Render" method. Considering the ideal preparation conditions (Taper angle was 6°, step depth was 1 mm, occlusal reduction was 2mm), four different configurations were modeled by changing the marginal design (chamfer, deep chamfer, shoulder 90°, shoulder 135°). PEEK, PEKK substructure, and composite superstructure were designed on created models. A total of 150N oblique force from two points and a total of 300N vertical force from three points were applied from occlusall. and the maximum principal stress, minimum principal stress, von Mises stress findings in the cortical bone, spongiose bone, and substructure were examined. The study was carried out by static linear analysis with a three-dimensional finite element stress analysis method. The highest maximum principal stress value in the cortical bone was observed when the PEEK+Shoulder 135° step at vertical force. The highest minimum principal stress value in the cortical bone was observed when the PEEK+Shoulder 90° step, and PEEK+deep chamfer step at oblique force. The highest maximum principal stress value in spongiose bone was observed when the PEEK+Shoulder 90° step. The highest minimum principal stress value in spongiose bone was observed when the PEEK+deep chamfer step at vertical force. The highest von Mises stress value in the substructure was observed when the PEKK+Deep chamfer step at oblique force. The lowest maximum principal stress value in the cortical bone was observed when the PEKK+Shoulder 135° step at oblique force. The lowest minimum principal stress value in the cortical bone was observed when the PEEK+Shoulder 135° step, and PEKK+shoulder 135° step at vertical force. The lowest maximum principal stress value in spongiose bone was observed when the PEEK+Shoulder 90° step. The lowest minimum principal stress value in spongiose bone was observed when the PEEK+Shoulder 135° step and PEKK+Shoulder 135° step at vertical force. The lowest von Mises stress value in the substructure was observed when the PEEK+Deep chamfer step at vertical force. When cortical and spongiose bone stress were evaluated, no destructive stress was observed. Considering the stresses occurring in the substructure the highest stress was observed in the chamfer step.