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Cosma C, Kessler J, Gebhardt A, Campbell I, Balc N. Improving the Mechanical Strength of Dental Applications and Lattice Structures SLM Processed. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E905. [PMID: 32085482 PMCID: PMC7078848 DOI: 10.3390/ma13040905] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/10/2020] [Accepted: 02/15/2020] [Indexed: 01/07/2023]
Abstract
To manufacture custom medical parts or scaffolds with reduced defects and high mechanical characteristics, new research on optimizing the selective laser melting (SLM) parameters are needed. In this work, a biocompatible powder, 316L stainless steel, is characterized to understand the particle size, distribution, shape and flowability. Examination revealed that the 316L particles are smooth, nearly spherical, their mean diameter is 39.09 μm and just 10% of them hold a diameter less than 21.18 μm. SLM parameters under consideration include laser power up to 200 W, 250-1500 mm/s scanning speed, 80 μm hatch spacing, 35 μm layer thickness and a preheated platform. The effect of these on processability is evaluated. More than 100 samples are SLM-manufactured with different process parameters. The tensile results show that is possible to raise the ultimate tensile strength up to 840 MPa, adapting the SLM parameters for a stable processability, avoiding the technological defects caused by residual stress. Correlating with other recent studies on SLM technology, the tensile strength is 20% improved. To validate the SLM parameters and conditions established, complex bioengineering applications such as dental bridges and macro-porous grafts are SLM-processed, demonstrating the potential to manufacture medical products with increased mechanical resistance made of 316L.
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Affiliation(s)
- Cosmin Cosma
- Department of Manufacturing Engineering, Technical University of Cluj-Napoca, 400641 Cluj-Napoca, Romania;
| | - Julia Kessler
- Institute for Toolless Fabrication, 52074 Aachen, Germany;
| | - Andreas Gebhardt
- Department of Mechanical Engineering and Mechatronics, FH Aachen University of Applied Sciences, 52064 Aachen, Germany;
| | - Ian Campbell
- Loughborough Design School, University Loughborough, Loughborough LE11 3TU, Leics, UK;
| | - Nicolae Balc
- Department of Manufacturing Engineering, Technical University of Cluj-Napoca, 400641 Cluj-Napoca, Romania;
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Tan N, Liu X, Cai Y, Zhang S, Jian B, Zhou Y, Xu X, Ren S, Wei H, Song Y. The influence of direct laser metal sintering implants on the early stages of osseointegration in diabetic mini-pigs. Int J Nanomedicine 2017; 12:5433-5442. [PMID: 28814861 PMCID: PMC5546787 DOI: 10.2147/ijn.s138615] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Background High failure rates of oral implants have been reported in diabetic patients due to the disruption of osseointegration. The aim of this study was to investigate whether direct laser metal sintering (DLMS) could improve osseointegration in diabetic animal models. Methods Surface characterizations were carried out on two types of implants. Cell morphology and the osteogenic-related gene expression of MG63 cells were observed under conditions of DLMS and microarc oxidation (MAO). A diabetes model in mini-pigs was established by intravenous injection of streptozotocin (150 mg/kg), and a total of 36 implants were inserted into the mandibular region. Micro-computed tomography (micro-CT) and histologic evaluations were performed 3 and 6 months after implantation. Results The Ra (the average of the absolute height of all points) of MAO surface was 2.3±0.3 µm while the DLMS surface showed the Ra of 27.4±1.1 µm. The cells on DLMS implants spread out more podia than those on MAO implants through cell morphology analysis. Osteogenic-related gene expression was also dramatically increased in the DLMS group. Obvious improvement was observed in the micro-CT and Van Gieson staining analyses of DLMS implants compared with MAO at 3 months, although this difference disappeared by 6 months. DLMS implants showed a higher bone–implant contact percentage (33.2%±11.2%) at 3 months compared with MAO group (18.9%±7.3%) while similar results were showed at 6 months between DLMS group (42.8%±10.1%) and MAO group (38.3%±10.8%). Conclusion The three-dimensional environment of implant surfaces with highly porous and fully interconnected channel and pore architectures can improve cell spreading and accelerate the progress of osseointegration in diabetic mini-pigs.
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Affiliation(s)
- Naiwen Tan
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China.,Department of Stomatology, Hospital 463 of PLA, Xi'an, Shaanxi, China
| | - Xiangwei Liu
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Yanhui Cai
- Department of Anesthesiology, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Sijia Zhang
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Bo Jian
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Yuchao Zhou
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Xiaoru Xu
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Shuai Ren
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Hongbo Wei
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Yingliang Song
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
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Poly-ε-caprolactone Coated and Functionalized Porous Titanium and Magnesium Implants for Enhancing Angiogenesis in Critically Sized Bone Defects. Int J Mol Sci 2015; 17:ijms17010001. [PMID: 26703586 PMCID: PMC4730248 DOI: 10.3390/ijms17010001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 12/10/2015] [Accepted: 12/14/2015] [Indexed: 11/26/2022] Open
Abstract
For healing of critically sized bone defects, biocompatible and angiogenesis supporting implants are favorable. Murine osteoblasts showed equal proliferation behavior on the polymers poly-ε-caprolactone (PCL) and poly-(3-hydroxybutyrate)/poly-(4-hydroxybutyrate) (P(3HB)/P(4HB)). As vitality was significantly better for PCL, it was chosen as a suitable coating material for further experiments. Titanium implants with 600 µm pore size were evaluated and found to be a good implant material for bone, as primary osteoblasts showed a vitality and proliferation onto the implants comparable to well bottom (WB). Pure porous titanium implants and PCL coated porous titanium implants were compared using Live Cell Imaging (LCI) with Green fluorescent protein (GFP)-osteoblasts. Cell count and cell covered area did not differ between the implants after seven days. To improve ingrowth of blood vessels into porous implants, proangiogenic factors like Vascular Endothelial Growth Factor (VEGF) and High Mobility Group Box 1 (HMGB1) were incorporated into PCL coated, porous titanium and magnesium implants. An angiogenesis assay was performed to establish an in vitro method for evaluating the impact of metallic implants on angiogenesis to reduce and refine animal experiments in future. Incorporated concentrations of proangiogenic factors were probably too low, as they did not lead to any effect. Magnesium implants did not yield evaluable results, as they led to pH increase and subsequent cell death.
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Rotaru H, Schumacher R, Kim SG, Dinu C. Selective laser melted titanium implants: a new technique for the reconstruction of extensive zygomatic complex defects. Maxillofac Plast Reconstr Surg 2015; 37:1. [PMID: 25654072 PMCID: PMC4309900 DOI: 10.1186/s40902-015-0001-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 01/09/2015] [Indexed: 11/13/2022] Open
Abstract
The restoration of extensive zygomatic complex defects is a surgical challenge owing to the difficulty of accurately restoring the normal anatomy, symmetry, proper facial projection and facial width. In the present study, an extensive post-traumatic zygomatic bone defect was reconstructed using a custom-made implant that was made with a selective laser melting (SLM) technique. The computer-designed implant had the proper geometry and fit perfectly into the defect without requiring any intraoperative adjustments. A one-year follow-up revealed a stable outcome with no complications.
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Affiliation(s)
- Horatiu Rotaru
- Department of Oral and Cranio-Maxillofacial Surgery, "Iuliu Hatieganu" University of Medicine and Pharmacy, Str. Motilor Nr. 33, 400001 Cluj-Napoca, Romania
| | - Ralf Schumacher
- School of Life Sciences, Institute for Medical and Analytical Technologies, University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, Switzerland
| | - Seong-Gon Kim
- Department of Oral and Maxillofacial Surgery, Gangneung-Wonju National University, Gangneung, South Korea
| | - Cristian Dinu
- Department of Oral and Cranio-Maxillofacial Surgery, "Iuliu Hatieganu" University of Medicine and Pharmacy, Str. Motilor Nr. 33, 400001 Cluj-Napoca, Romania
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Direct metal laser sintering titanium dental implants: a review of the current literature. Int J Biomater 2014; 2014:461534. [PMID: 25525434 PMCID: PMC4267165 DOI: 10.1155/2014/461534] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 10/16/2014] [Accepted: 11/06/2014] [Indexed: 12/14/2022] Open
Abstract
Statement of Problem. Direct metal laser sintering (DMLS) is a technology that allows fabrication of complex-shaped objects from powder-based materials, according to a three-dimensional (3D) computer model. With DMLS, it is possible to fabricate titanium dental implants with an inherently porous surface, a key property required of implantation devices. Objective. The aim of this review was to evaluate the evidence for the reliability of DMLS titanium dental implants and their clinical and histologic/histomorphometric outcomes, as well as their mechanical properties. Materials and Methods. Electronic database searches were performed. Inclusion criteria were clinical and radiographic studies, histologic/histomorphometric studies in humans and animals, mechanical evaluations, and in vitro cell culture studies on DMLS titanium implants. Meta-analysis could be performed only for randomized controlled trials (RCTs); to evaluate the methodological quality of observational human studies, the Newcastle-Ottawa scale (NOS) was used. Results. Twenty-seven studies were included in this review. No RCTs were found, and meta-analysis could not be performed. The outcomes of observational human studies were assessed using the NOS: these studies showed medium methodological quality. Conclusions. Several studies have demonstrated the potential for the use of DMLS titanium implants. However, further studies that demonstrate the benefits of DMLS implants over conventional implants are needed.
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