The broad applications of 3D-printed poly-ether-ether-ketone (3D-PEEK) structures are largely hampered by their inadequate mechanical properties which can be improved by post treatments. At present, thermal annealing is generally used to improve the mechanical properties of 3D-PEEK. However, it cannot simultaneously improve the strength and ductility. Here, a cost-effective post-processing method is developed to improve the mechanical properties of 3D-PEEK, based on annealing in nonsolvent vapor at room temperature. The annealing in nonsolvent vapor at room temperature simultaneously improves the strength, ductility, and fracture energy of as-printed 3D-PEEK by 22.6%, 151.3% and 109.1%, respectively. The improved mechanical properties are attributed to enhanced interfacial bonding, increased crystallinity, decreased pinhole defects, and stress relaxation in the 3D-PEEK. Moreover, the annealing in both polar solvents (such as acetone and chloroform) and nonpolar solvents (such as n-hexane) are demonstrated to be effective for improving the mechanical properties of 3D-PEEK. The nonsolvent vapor-annealed 3D-PEEK can thus have potential applications in the fields of medical implants, automotive, aerospace, and more. This article is protected by copyright. All rights reserved.

Improvement in Mechanical Properties of 3D-Printed PEEK Structure by Nonsolvent Vapor Annealing.

The high cost of biofabricated titanium mesh plates can make them out of reach for hospitals in low-income countries. To increase the availability of cranioplasty, the authors of this work investigated the production of polymer-based endoprostheses. Recently, cheap, popular desktop 3D printers have generated sufficient opportunities to provide patients with on-demand and on-site help. This study also examines the technologies of 3D printing, including SLM, SLS, FFF, DLP, and SLA. The authors focused their interest on the materials in fabrication, which include PLA, ABS, PET-G, PEEK, and PMMA. Three-dimensional printed prostheses are modeled using widely available CAD software with the help of patient-specific DICOM files. Even though the topic is insufficiently researched, it can be perceived as a relatively safe procedure with a minimal complication rate. There have also been some initial studies on the costs and legal regulations. Early case studies provide information on dozens of patients living with self-made prostheses and who are experiencing significant improvements in their quality of life. Budget 3D-printed endoprostheses are reliable and are reported to be significantly cheaper than the popular counterparts manufactured from polypropylene polyester.

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Low-Cost Cranioplasty—A Systematic Review of 3D Printing in Medicine

Fused filament fabrication (FFF), also known as fused deposition modeling, is the leading technology for polymer-based additive manufacturing. The simplicity, along with the cleanness, the affordability, and the multi-material capability, are some of the main advantages that have prompted this success. Nonetheless, the uptake of FFF in industry is hampered by the limited functionality of commercial filaments, that are often based on plain thermoplastics. The future growth of FFF into new markets needs a significant improvement of available materials. However, materials requirements in FFF are complicated and often mutually conflicting. Whereas heuristic approaches to materials design imply significant costs in terms of time, energy, and materials, a critical survey of the main requirements that a new material should fulfill in order to be printable and suitable for commercial adoption is still missing. In order to bridge this gap, the present paper analyzes the workflow from filament production to end-of-life disposal of printed objects, and, for each step, brings to light the governing materials properties. Wherever possible, practical guidelines are given on acceptable values. Existing lacks of knowledge are identified to direct future studies. The ultimate goal is to provide a road map to making materials development in FFF more efficient. 

Materials Requirements in Fused Filament Fabrication: A Framework for the Design of Next‐Generation 3D Printable Thermoplastics and Composites

Polyetheretherketone (PEEK) is a thermoplastic material widely used in engineering applications due to its good biomechanical properties and high temperature stability. Compared to traditional metal and ceramic dental materials, PEEK dental implants exhibit less stress shielding, thus better matching the mechanical properties of bone. As a promising medical material, PEEK can be used as implant abutments, removable and fixed prostheses, and maxillofacial prostheses. It can be blended with materials such as fibers and ceramics to improve its mechanical strength for better clinical dental applications. Compared to conventional pressed and CAD/CAM milling fabrication, 3D-printed PEEK exhibits excellent flexural and tensile strength and parameters such as printing temperature and speed can affect its mechanical properties. However, the bioinert nature of PEEK can make adhesive bonding difficult. The bond strength can be improved by roughening or introducing functional groups on the PEEK surface by sandblasting, acid etching, plasma treatment, laser treatment, and adhesive systems. This paper provides a comprehensive overview of the research progress on the mechanical properties of PEEK for dental applications in the context of specific applications, composites, and their preparation processes. In addition, the research on the adhesive properties of PEEK over the past few years is highlighted. Thus, this review aims to build a conceptual and practical toolkit for the study of the mechanical and adhesive properties of PEEK materials. More importantly, it provides a rationale and a general new basis for the application of PEEK in the dental field.

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PEEK for Oral Applications: Recent Advances in Mechanical and Adhesive Properties

Effect of 3D printing process parameters on surface and mechanical properties of FFF-printed PEEK

Polyether ether ketone (PEEK) is an organic polymer that has excellent mechanical, chemical properties and can be additively manufactured (3D-printed) with ease. The use of 3D-printed PEEK has been growing in many fields. This article systematically reviews the current status of 3D-printed PEEK that has been used in various areas, including medical, chemical, aerospace, and electronics. A search of the use of 3D-printed PEEK articles published until September 2021 in various fields was performed using various databases. After reviewing the articles, and those which matched the inclusion criteria set for this systematic review, we found that the printing of PEEK is mainly performed by fused filament fabrication (FFF) or fused deposition modeling (FDM) printers. Based on the results of this systematic review, it was concluded that PEEK is a versatile material, and 3D-printed PEEK is finding applications in numerous industries. However, most of the applications are still in the research phase. Still, given how the research on PEEK is progressing and its additive manufacturing, it will soon be commercialized for many applications in numerous industries.

Zuri Rashad

Papers

Applications of 3D-Printed PEEK via Fused Filament Fabrication: A Systematic Review