The research status and future direction of polyetheretherketone in dental implant -A comprehensive review.

Currently, dental implants primarily rely on the use of titanium and titanium alloys. However, the extensive utilization of these materials in clinical practice has unveiled various problems including stress shielding, corrosion, allergic reactions, cytotoxicity, and image artifacts. As a result, polyetheretherketone (PEEK) has emerged as a notable alternative due to its favorable mechanical properties, corrosion resistance, wear resistance, biocompatibility, radiation penetrability and MRI compatibility. Meanwhile, the advancement and extensive application of 3D printing technology has expanded the range of medical applications for PEEK, including artificial spines, skulls, ribs, shinbones, hip joints, and temporomandibular joints. In this review, we aim to assess the advantages and disadvantages of PEEK as a dental implant material, summarize the measures taken to address its shortcomings and their effects, and provide insight into the future potential of PEEK in dental implant applications, with the goal of offering guidance and reference for future research endeavors.

Additive manufactured polyether-ether-ketone implants for orthopaedic applications: a narrative review.

Polyether-ether-ketone (PEEK) is believed to be the next-generation biomedical material for orthopaedic implants that may replace metal materials because of its good biocompatibility, appropriate mechanical properties and radiolucency. Currently, some PEEK implants have been used successfully for many years. However, there is no customised PEEK orthopaedic implant made by additive manufacturing licensed for the market, although clinical trials have been increasingly reported. In this review article, design criteria, including geometric matching, functional restoration, strength safety, early fixation, long-term stability and manufacturing capability, are summarised, focusing on the clinical requirements. An integrated framework of design and manufacturing processes to create customised PEEK implants is presented, and several typical clinical applications such as cranioplasty patches, rib prostheses, mandibular prostheses, scapula prostheses and femoral prostheses are described. The main technical challenge faced by PEEK orthopaedic implants lies in the poor bonding with bone and soft tissue due to its biological inertness, which may be solved by adding bioactive fillers and manufacturing porous architecture. The lack of technical standards is also one of the major factors preventing additive-manufactured customised PEEK orthopaedic implants from clinical translation, and it is good to see that the abundance of standards in the field of additive-manufactured medical devices is helping them enter the clinical market.

Preparation and Performance Evaluation of Duotone 3D-Printed Polyetheretherketone as Oral Prosthetic Materials: A Proof-of-Concept Study.

Literature has reported the successful use of 3D printed polyetheretherketone (PEEK) to fabricate human body implants and oral prostheses. However, the current 3D printed PEEK (brown color) cannot mimic the vivid color of oral tissues and thus cannot meet the esthetical need for dental application. Therefore, titanium dioxide (TiO2) and ferric oxide (Fe2O3) were incorporated into PEEK to prepare a series of tooth-color and gingival-color PEEK composites in this study. Through color measurements and mechanical tests, the color value and mechanical performance of the 3D printed PEEK composites were evaluated. In addition, duotone PEEK specimens were printed by a double nozzle with an interface between tooth-color and gingival-color parts. The mechanical performance of duotone PEEK with two different interfaces (horizontal and vertical) was investigated. With the addition of TiO2 and Fe2O3, the colors of 3D printed PEEK composites become closer to that of dental shade guides. 3D printed PEEK composites generally demonstrated superior tensile and flexural properties and hence have great potential in the dental application. In addition, duotone 3D printed PEEK with a horizontal interfacial orientation presented better mechanical performance than that with a vertical one.

Biomechanical evaluation of a customized 3D-printed polyetheretherketone condylar prosthesis.

The present study aimed to evaluate the biomechanical behavior of a custom 3D-printed polyetheretherketone (PEEK) condylar prosthesis using finite element analysis and mechanical testing. The Mimics software was used to create a 3D model of the mandible, which was then imported into Geomagic Studio software to perform osteotomy of the lesion area. A customized PEEK condyle prosthesis was then designed and the finite element model of the PEEK condyle prosthesis, mandible and fixation screw was established. The maximum stress of the prosthesis and screws, as well as stress and strain of the cortical and cancellous bones in the intercuspal position, incisal clench, left unilateral molar clench and right unilateral molar clench was analyzed. The biomechanical properties of the prosthesis were studied using two models with different lesion ranges. To simulate the actual clinical situation, a special fixture was designed. The compression performance was tested at 1 mm/min for the condyle prosthesis, prepared by fused deposition modeling (FDM). The results of a finite element analysis suggested that the maximum stress of the condyle was 10.733 MPa and the maximum stress of the screw was 9.7075 MPa; both were far less than the yield strength of the material. The maximum force that the two designed prostheses were able to withstand was 3,814.7±442.6 N (Model A) and 4,245.7±348.3 N (Model B). Overall, the customized PEEK condyle prostheses prepared by FDM exhibited a uniform stress distribution and good mechanical properties, providing a theoretical basis for PEEK as a reconstruction material for repairing the temporomandibular joint.

Effects of printing path and material components on mechanical properties of 3D-printed polyether-ether-ketone/hydroxyapatite composites.

Polyether-ether-ketone (PEEK) exhibits excellent mechanical properties and biocompatibility. Three-dimensional (3D) printing of PEEK bone substitutes has been widely used in clinical application. However, the inertness of pure PEEK hinders its integration with the surrounding bone tissue. In this study, for the first time, PEEK/hydroxyapatite (HA) composite specimens were fabricated using fused filament fabrication (FFF) technology. PEEK/HA filaments with HA contents of 0-30 wt% were fabricated via mechanical mixing and extrusion. The HA distributions inside the composite matrix and the surface morphology characteristics of the PEEK/HA composites were examined. The effects of the printing path and HA content on the mechanics of the PEEK/HA composites were systematically investigated. The results indicated that the HA particles were uniformly distributed on the composite matrix. With an increase in the HA content, the modulus of the PEEK/HA composite increased, while the strength and failure strain concomitantly decreased. When the HA content increased to 30 wt%, the tensile modulus of the composite increased by 68.6% compared with that of pure PEEK printed along the horizontal 90° path, while the tensile strength decreased by 48.2% compared with that of pure PEEK printed along the vertical 90° path. The fracture elongation of the printed specimens with different HA contents decreased in the following order: horizontal 0° > horizontal 90° > vertical 90°. The best comprehensive mechanical properties were achieved for pure PEEK fabricated along the horizontal 0° path. The results indicate that FFF technology is applicable for additive manufacturing of PEEK/HA composites with controllable compositions. Printed PEEK/HA composites have potential for applications in the design and manufacturing of personalized bone substitutes.

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

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

Custom design and biomechanical analysis of 3D-printed PEEK rib prostheses.

A tumour resection normally involves a large tissue resection and bone replacement. Polyether ether ketone (PEEK) has become a suitable candidate for use in various prostheses owing to its lightness in weight, modulus close to that of natural bone, and good biocompatibility, among other factors. This study proposes a new design method for a rib prosthesis using the centroid trajectory of the natural replaced rib, where the strength can be adjusted by monitoring the cross-sectional area, shape, and properties. A custom-designed rib prosthesis was manufactured using fused deposition modelling (FDM) manufacturing technology, and the mechanical behaviour was found to be close to that of a natural rib. A finite element analysis of the designed rib was carried out under similar loading conditions to those used in mechanical testing. The results indicate that the centroid trajectory derived from a natural rib diaphysis can provide reliable guidance for the design of a rib prosthesis. Such methodology not only offers considerable design freedom in terms of shape and required strength, but also benefits the quality of the surface finishing for samples manufactured using the FDM technique. FDM-printed PEEK rib prostheses have been successfully implanted, and good clinical performances have been achieved.

Rotational diffusion of magnetic nanoparticles in protein solutions.

The rotational diffusion of polyethylene glycol coated magnetic nanoparticles in serum albumin solutions was investigated in a range spanning 0mgmL-1 to 200mgmL-1. Rotational diffusivities were determined from dynamic magnetic susceptibility measurements, which provide a non-optical means to probe rotation of nanoparticles in small volume samples. Experimental rotational diffusivities were compared to those estimated using the Stokes-Einstein relation and macroscopic measurements of the viscosity of the protein solutions. Excellent agreement was found between experimental measurements and theoretical predictions for serum albumin solutions buffered at physiological pH and for serum albumin solutions at acidic pH prepared using simple acids at physiological ionic strengths. For serum albumin solutions prepared using citrate buffer at acidic pH, we observed a discrepancy between the experimental rotational diffusivity and that predicted from the Stokes-Einstein relation. In contrast, when the pH was adjusted with a simple acid and salt at physiological ionic strength we observed agreement between the experimental rotational diffusivity and that predicted from the Stokes-Einstein relation. Because of the role of citrate ions in causing protein aggregation, we believe these observations suggest that dynamic magnetic susceptibility measurement of the rotational diffusivity of the nanoparticles is sensitive to gelation/crosslinking of proteins.