Problems and trends of technique and clinical application of metallic biomaterials prepared by three-dimensional printing technology / 中国组织工程研究

BACKGROUND: Three-dimensional (3D) printing technology has been applied to fabricate the personalized metallic biomaterials with low elastic modulus, low cost and precision, aiming at overcoming the defects of the biomaterials fabricated by the traditional technology. OJECTIVE: To summarize the development of metallic biomaterials fabricated by the 3D printing technology. METHODS: The articles were searched by using the databases of PubMed and CNKI. The key words were “metallic biomaterials, metallic 3D printing technology, surgical implants, oral application and cardiovascular devices” in Chinese and in English. As a result, 92 articles were applied after reading and analyzing the title and abstract of the articles published between June 2010 and June 2020. RESULTS AND CONCLUSION: In biomedical applications, metallic 3D printing technology can be divided into two categories: powder bed selective melting and directional energy deposition. Metallic 3D printing enables mass production of metal implants with complex geometric shapes and internal structures, as well as customized medical implant production that meets the needs of specific patients. Faced with many metallic printing technologies, it is necessary to choose a suitable additive manufacturing process according to the complexity and different design of materials. At present, 3D printing of metallic biomaterials such as titanium and cobalt-chromium alloys has made substantial progress, and has been used in clinical orthopedics, dentistry and vascular surgery. Research on 3D printing metal biomaterials based on magnesium and iron is still carried on.

Modelo de endurecimiento isotrópico con esquema de integración explícita para biomateriales y su aplicación a la expansión de stents / Isotropic hardening model with explicit integration scheme for biomaterial and its application to stents expansion

Se presenta un modelo de endurecimiento isotrópico para biomateriales metálicos, el cual emplea un esquema de integración explícita bajo una formulación incremental. Para la implementación computacional se programó un elemento finito de usuario UEL en lenguaje FORTRAN para su ejecución en el software ABAQUS. Con el fin de validar el modelo se resuelven dos ejemplos tipo benchmark y sus resultados son comparados con ANSYS y el UMAT de Dunne y Petrinic para ABAQUS. Finalmente, el modelo es usado para simular la extensión de un stent coronario fabricado en acero inoxidable 316L. Se concluye que el modelo posee un error numérico aceptable teniendo en cuenta que el elemento finito fue programado por completo y no posee ninguna de las optimizaciones de los códigos comerciales. En trabajos futuros el UEL será acoplado con modelos de mecánica de daño continuo para la predicción de la falla por fatiga, cuyo análisis es un estándar básico en la manufactura de stents

A isotropic hardening model is presented for metallic biomaterials, which uses a explicit integration scheme under increasing formula. To computer implementation a finite element from UEL user was programmed in FORTRAN language for its execution in the ABAQUS software. To model validation two examples type benchmark were solved and results are compared with ANSYS and the UMAT of Dunne and Petrinic for ABAQUS. Finally, model is used to simulate the extension of a coronary stent manufactures in 316L stainless steel. We conclude that the model has an acceptable numerical error taking into account that finite element was programmed as a whole and has not any of the optimizations of commercial codes. In future papers the UEL will be coupled with continuous damage mechanics model to predict the failure due to fatigue, whose analysis is a basic standard in stent manufacturing