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Design and testing 3D printed structures for bone replacements

Ikonomov P. G., Yahamed A., Fleming P. D., Pekarovicova A.

Journal of Achievements in Materials and Manufacturing Engineering

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2020

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Vol. 101, nr 2

76--85

EN

Purpose: 3D printing has shown enormous potential for building plastic products, including bone, organs, and body parts. The technology has progressed from visualization and preoperation training to the 3D printing of customized body parts and implants. This research aims to create 3D printed bone structure from plastics and test the mechanical properties of the cortical and trabecular bone structures if they match the real bone structure strength. Design/methodology/approach: We used Digital Imaging, and Communications in Medicine (DICOM) images from Computer Tomography (CT) scans to created external bone structures. These images' resolution did not allow the creation of fine trabecular bone structures, so we used 3D modeling software to engineer special 3D void honeycomb structures (with triangular, square, and hexagonal shapes). Another reason to design void structures is that the 3D printing of complex shapes without support materials is problematic. After designing and 3D printing of the 3D bone structures, their mechanical properties need to be tested. Findings: 3D bone models, solid (cortical), and void (trabecular) bone structures were designed, 3D printed, and then tested. Tensile, bending, and compression testing was performed. Testing the mechanical properties of the honeycomb structures (triangular, square, and hexagonal) shows that their strength and modulus are higher than those of the real trabecular bones. The results show that 3D printed honeycomb structures mechanical properties can match and some cases exceeding the properties of the actual bones trabecular structures, while the sold structures have lower mechanical properties than the bone cortical structures. Research limitations/implications: During the 3D printing experiments, we found that 3D printers, in general, have low resolution, not enough to print fine trabecular bone structures. To solve the existing 3D printing technology's insufficient resolution, we later designed and built an SLA (stereolithography) 3D printer with high printing resolution (10 micrometers). Another limitation we found is the lack of biocompatible materials for 3D printing of bone structures. Future research work is in progress formulating superior ink/resin for bone structures 3D printing. Further, clinical trials need to be performed to investigate 3D printed parts’ influence on the healing of bone structures. Practical implications: We found that the 3D void (honeycomb) structures will have an impact not only on building bone structures but also in engineering special structures for industrial applications that can reduce the weight, time, and the cost of the material, while still keep sufficient mechanical properties. Originality/value: Designing and testing 3D printed bone models, solid (cortical), and void (trabecular) bone structures could replace bones. Design and test special void honeycomb structures as a replacement for cortical bone structures.

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Badanie naprężeń i przemieszczeń struktur kostnych

Domagała Z., Drapikowski P.

Studia z Automatyki i Informatyki

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2009

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T. 34

7-20

PL

W pracy przedstawiono biomechaniczny model kości udowej poddany maksymalnym obciążeniom statycznym. Wyznaczono rozkład naprężeń i przemieszczeń korzystając z metody elementów skończonych (MES). Przedstawiono i zbadano różne aspekty modelowania kości udowej takie jak: model geometryczny kości, oszacowanie właściwości mechanicznych, modele obciążeń stawu biodrowego, rodzaj siatki i wielkość elementów skończonych. Porównano rozkład naprężeń i przemieszczeń modelu fragmentu kości rekonstruowanego na podstawie indywidualnych danych pacjenta z modelem całej kości. Wyniki analizy uzyskane dla fragmentu kości znacznie odbiegają od wyników dla całej kości.

EN

The work presents the biomechanical model of the human proximal femur and the Finite Element (FE) results of displacements and strains as the response to quasi-static load. Different aspects of proximal femur modeling as: geometrical model, estimation of mechanical properties of cortical and trabecular regions, load models of hip joint, kind and size of FE mesh are presented and investigated. Displacements and strains of part of the femur reconstructed based on the CT scans were compared to the whole femur. FE results of both models are different.

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Relationships between structure, density and strength of human trabecular bone

Mazurkiewicz A., Topoliński T.

Acta of Bioengineering and Biomechanics

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2009

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Vol. 11, nr 4

55-61

EN

The article deals with the examination of the relationships between density, structure parameters and strength of human trabecular bone. The tests were carried out on the samples taken from osteoporotic and coxarthrotic human femoral heads. The samples cylindrical in shape had the diameters of 10 mm and the height of 8.5 mm. During the tests with uCT scanner the parameters of a sample structure were measured. Bone mineral density (BMD) was measured as well. The samples were subjected to compression in order to assess the ultimate compression strength (fi)c. The relationships between two-element combinations (BMD and one of the structure parameters) and the compression strength of the samples have been studied. The consistence of the results for multiple regression and response surface regression was estimated based on the correlation coefficient R. For the examined pairs of parameters, the value R increased in the range of 7÷30% in comparison with the case where for the strength description only BMD was used. Additionally, the authors' own models of two-variable regression was calculated. The comparison of the results obtained for all models of regression based on the coefficient E proved the consistence of these results.

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Materiały hydroksyapatytowe stosowane w implantologii

Sobczak A., Kowalski Z.

Czasopismo Techniczne. Chemia

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2007

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R. 104, z. 1-Ch

149-158

PL

W artykule przedstawiono strukturę tkanki kostnej oraz materiały hydroksyapatytowe stosowane w implantologii do wypełniania ubytków kostnych. Do hydroksyapatytowych biomateriałów stosowanych w chirurgii kostnej zalicza się materiały porowate, powłokowe oraz kompozyty, w których drugą fazą mogą być metale, materiały węglowe oraz polimery zarówno biodegradowalne, jak i biostabilne.

EN

In this article were presented bone tissue structure and hydroxyapatite materials used in implantology as filling material of bone lack. Hydroxyapatite biomaterials applied in bone surgery included porous materials, coating materials and composites in which second phase can be metals, carbon materials and also polymers both biodegradable and biostable.

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Dynamics of the human thorax with the Lorenz pectus bar

Awrejcewicz J., Łuczak B.

Vibrations in Physical Systems

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2006

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Vol. 22

59--64