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1.
Mater Sci Eng C Mater Biol Appl ; 128: 112333, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474884

RESUMO

Polyetheretherketone (PEEK) was widely applied into fabricating of orthopaedic implants, benefitting its excellent biocompatibility and similar mechanical properties to native bones. However, the inertness of PEEK hinders its integration with the surrounding bone tissue. Here PEEK scaffolds with a series of hydroxyapatite (HA) contents in gradient were manufactured via fused filament fabrication (FFF) 3D printing techniques. The influence of the pore size, HA content and printing direction on the mechanical properties of the PEEK/HA scaffolds was systematically evaluated. By adjusting the pore size and HA contents, the elastic modulus of the PEEK/HA scaffolds can be widely tuned in the range of 624.7-50.6 MPa, similar to the variation range of natural cancellous bone. Meanwhile, the scaffolds exhibited higher Young's modulus and lower compressive strength along Z printing direction. The mapping relationship among geometric parameters, HA content, printing direction and mechanical properties was established, which gave more accurate predictions and controllability of the modulus and strength of scaffolds. The PEEK/HA scaffolds with the micro-structured surface could promote cell attachment and mineralization in vitro. Therefore, the FFF-printed PEEK/HA composites scaffolds can be a good candidate for bone grafting and tissue engineering.


Assuntos
Durapatita , Cetonas , Benzofenonas , Polietilenoglicóis , Polímeros , Porosidade , Impressão Tridimensional , Tecidos Suporte
2.
J Mech Behav Biomed Mater ; 118: 104475, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33773239

RESUMO

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.


Assuntos
Materiais Biocompatíveis , Durapatita , Éteres , Cetonas , Polietilenoglicóis , Impressão Tridimensional
3.
J Mech Behav Biomed Mater ; 116: 104335, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33494021

RESUMO

Functional reconstruction of large-size mandibular continuity defect is still a major challenge in the oral and maxillofacial surgery due to the unsatisfactory repair effects and various complications. This study aimed to develop a new functional repair method for mandibular defects combined with 3D-printed polyetheretherketone (PEEK) implant and the free vascularized fibula graft, and evaluated the service performance of the implant under whole masticatory motion. The design criteria and workflows of the mandibular reconstruction were established based on the requirements of safety, functionality, and shape consistency. Both the biomechanical behavior and the mechanobiological property of mandibular reconstruction under various masticatory motion were investigated by the finite element analysis. The maximum von Mises stress of each component was lower than the yield strength of the corresponding material and the safety factor was more than 2.3 times, which indicated the security of the repair method can be guaranteed. Moreover, the actual deformation of the reconstruction model was lower than that of the normal mandible under most clenching tasks, which assured the primary stability. More than 80% of the volume elements in the bone graft can obtain effective mechanical stimulation, which benefited to reduce the risks of bone resorption. Finally, the novel repair method was applied in clinic and good clinical performances have been achieved. Compared with the conventional fibular bone graft for surgical mandibular reconstruction, this study provides excellent safety and stability to accomplish the functional reconstruction and aesthetic restoration of the mandible defect.


Assuntos
Reconstrução Mandibular , Transplante Ósseo , Fíbula , Cetonas , Mandíbula/cirurgia , Polietilenoglicóis , Impressão Tridimensional
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