Design and Additive Manufacturing of Acetabular Implant with Continuously Graded Porosity
Porous structured metallic implants are preferable as bone graft substitutes due to their faster tissue integration mediated by bone in-growth and vascularization. The porous scaffolds/implants should also mimic the graded structure of natural bone to ensure a match of mechanical properties. This ar...
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MDPI AG
2023-06-01
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| Series: | Bioengineering |
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| Online Access: | https://www.mdpi.com/2306-5354/10/6/675 |
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| author | Sumanta Mukherjee Santanu Dhara Partha Saha |
| author_facet | Sumanta Mukherjee Santanu Dhara Partha Saha |
| author_sort | Sumanta Mukherjee |
| collection | DOAJ |
| description | Porous structured metallic implants are preferable as bone graft substitutes due to their faster tissue integration mediated by bone in-growth and vascularization. The porous scaffolds/implants should also mimic the graded structure of natural bone to ensure a match of mechanical properties. This article presents a method for designing a graded porous structured acetabular implant and identifies suitable parameters for manufacturing the model through additive manufacturing. The design method is based on slice-wise modification to ensure continuity of gradation. Modification of the slices was achieved through the binary image processing route. A geodesic dome-type design was adopted for developing the acetabular cup model from the graded porous structure. The model had a solid shell with the target porosity and pore size gradually changing from 65% and 950 µm, respectively, in the inner side to 75% and 650 µm, respectively, towards the periphery. The required dimensions of the unit structures and the combinations of pore structure and strut diameter necessary to obtain the target porosity and pore size were determined analytically. Suitable process parameters were identified to manufacture the model by Direct Metal Laser Sintering (DMLS) using Ti6Al4V powder after carrying out a detailed experimental study to minimize the variation of surface roughness and warping over different build angles of the strut structures. Dual-contour scanning was implemented to simplify the scan strategy. The minimum diameter of struts that could be manufactured using the selected scanning strategy and scanning parameters was found to be 375 µm. Finally, the model was built and from the micro-CT data, the porosities and pore sizes were found to be closely conforming to the designed values. The stiffness of the structures, as found from compression testing, was also found to match with that of human trabecular bone well. Further, the structure exhibited compliant bending-dominated behaviour under compressive loading. |
| first_indexed | 2024-03-11T02:45:33Z |
| format | Article |
| id | doaj.art-395cd398867e4fcca581db961ca6be6b |
| institution | Directory Open Access Journal |
| issn | 2306-5354 |
| language | English |
| last_indexed | 2024-03-11T02:45:33Z |
| publishDate | 2023-06-01 |
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| series | Bioengineering |
| spelling | doaj.art-395cd398867e4fcca581db961ca6be6b2023-11-18T09:21:12ZengMDPI AGBioengineering2306-53542023-06-0110667510.3390/bioengineering10060675Design and Additive Manufacturing of Acetabular Implant with Continuously Graded PorositySumanta Mukherjee0Santanu Dhara1Partha Saha2Production Engineering Department, BIT Sindri, Dhanbad 828123, IndiaSchool of Medical Science and Technology, Indian Institute of Technology, Kharagpur 721302, IndiaMechanical Engineering Department, Indian Institute of Technology, Kharagpur 721302, IndiaPorous structured metallic implants are preferable as bone graft substitutes due to their faster tissue integration mediated by bone in-growth and vascularization. The porous scaffolds/implants should also mimic the graded structure of natural bone to ensure a match of mechanical properties. This article presents a method for designing a graded porous structured acetabular implant and identifies suitable parameters for manufacturing the model through additive manufacturing. The design method is based on slice-wise modification to ensure continuity of gradation. Modification of the slices was achieved through the binary image processing route. A geodesic dome-type design was adopted for developing the acetabular cup model from the graded porous structure. The model had a solid shell with the target porosity and pore size gradually changing from 65% and 950 µm, respectively, in the inner side to 75% and 650 µm, respectively, towards the periphery. The required dimensions of the unit structures and the combinations of pore structure and strut diameter necessary to obtain the target porosity and pore size were determined analytically. Suitable process parameters were identified to manufacture the model by Direct Metal Laser Sintering (DMLS) using Ti6Al4V powder after carrying out a detailed experimental study to minimize the variation of surface roughness and warping over different build angles of the strut structures. Dual-contour scanning was implemented to simplify the scan strategy. The minimum diameter of struts that could be manufactured using the selected scanning strategy and scanning parameters was found to be 375 µm. Finally, the model was built and from the micro-CT data, the porosities and pore sizes were found to be closely conforming to the designed values. The stiffness of the structures, as found from compression testing, was also found to match with that of human trabecular bone well. Further, the structure exhibited compliant bending-dominated behaviour under compressive loading.https://www.mdpi.com/2306-5354/10/6/675additive manufacturinggraded porosityacetabular cupTi6Al4VDMLS |
| spellingShingle | Sumanta Mukherjee Santanu Dhara Partha Saha Design and Additive Manufacturing of Acetabular Implant with Continuously Graded Porosity Bioengineering additive manufacturing graded porosity acetabular cup Ti6Al4V DMLS |
| title | Design and Additive Manufacturing of Acetabular Implant with Continuously Graded Porosity |
| title_full | Design and Additive Manufacturing of Acetabular Implant with Continuously Graded Porosity |
| title_fullStr | Design and Additive Manufacturing of Acetabular Implant with Continuously Graded Porosity |
| title_full_unstemmed | Design and Additive Manufacturing of Acetabular Implant with Continuously Graded Porosity |
| title_short | Design and Additive Manufacturing of Acetabular Implant with Continuously Graded Porosity |
| title_sort | design and additive manufacturing of acetabular implant with continuously graded porosity |
| topic | additive manufacturing graded porosity acetabular cup Ti6Al4V DMLS |
| url | https://www.mdpi.com/2306-5354/10/6/675 |
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