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Additive manufacturing of titanium alloys in the biomedical field: processes, properties and applications. J Appl Biomater Funct Mater 2017; 16:57-67. [DOI: 10.5301/jabfm.5000371] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The mechanical properties and biocompatibility of titanium alloy medical devices and implants produced by additive manufacturing (AM) technologies – in particular, selective laser melting (SLM), electron beam melting (EBM) and laser metal deposition (LMD) – have been investigated by several researchers demonstrating how these innovative processes are able to fulfil medical requirements for clinical applications. This work reviews the advantages given by these technologies, which include the possibility to create porous complex structures to improve osseointegration and mechanical properties (best match with the modulus of elasticity of local bone), to lower processing costs, to produce custom-made implants according to the data for the patient acquired via computed tomography and to reduce waste.
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52
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Wurm MC, Möst T, Bergauer B, Rietzel D, Neukam FW, Cifuentes SC, Wilmowsky CV. In-vitro evaluation of Polylactic acid (PLA) manufactured by fused deposition modeling. J Biol Eng 2017; 11:29. [PMID: 28919925 PMCID: PMC5594599 DOI: 10.1186/s13036-017-0073-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 08/01/2017] [Indexed: 12/02/2022] Open
Abstract
Background With additive manufacturing (AM) individual and biocompatible implants can be generated by using suitable materials. The aim of this study was to investigate the biological effects of polylactic acid (PLA) manufactured by Fused Deposition Modeling (FDM) on osteoblasts in vitro according to European Norm / International Organization for Standardization 10,993–5. Method Human osteoblasts (hFOB 1.19) were seeded onto PLA samples produced by FDM and investigated for cell viability by fluorescence staining after 24 h. Cell proliferation was measured after 1, 3, 7 and 10 days by cell-counting and cell morphology was evaluated by scanning electron microscopy. For control, we used titanium samples and polystyrene (PS). Results Cell viability showed higher viability on PLA (95,3% ± 2.1%) than in control (91,7% ±2,7%). Cell proliferation was highest in the control group (polystyrene) and higher on PLA samples compared to the titanium samples. Scanning electron microscopy revealed homogenous covering of sample surface with regularly spread cells on PLA as well as on titanium. Conclusion The manufacturing of PLA discs from polylactic acid using FDM was successful. The in vitro investigation with human fetal osteoblasts showed no cytotoxic effects. Furthermore, FDM does not seem to alter biocompatibility of PLA. Nonetheless osteoblasts showed reduced growth on PLA compared to the polystyrene control within the cell experiments. This could be attributed to surface roughness and possible release of residual monomers. Those influences could be investigated in further studies and thus lead to improvement in the additive manufacturing process. In addition, further research focused on the effect of PLA on bone growth should follow. In summary, PLA processed in Fused Deposition Modelling seems to be an attractive material and method for reconstructive surgery because of their biocompatibility and the possibility to produce individually shaped scaffolds.
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Affiliation(s)
- Matthias C Wurm
- Department of Oral and Maxillofacial Surgery, University Hospital Erlangen, Glueckstrasse 11, 91054 Erlangen, Germany
| | - Tobias Möst
- Department of Oral and Maxillofacial Surgery, University Hospital Erlangen, Glueckstrasse 11, 91054 Erlangen, Germany
| | - Bastian Bergauer
- Department of Oral and Maxillofacial Surgery, University Hospital Erlangen, Glueckstrasse 11, 91054 Erlangen, Germany
| | - Dominik Rietzel
- Institute for Polymer Technology, Friedrich-Alexander-University Erlangen-Nuremberg, Am Weichselgarten 9, 91058 Erlangen, Germany
| | - Friedrich Wilhelm Neukam
- Department of Oral and Maxillofacial Surgery, University Hospital Erlangen, Glueckstrasse 11, 91054 Erlangen, Germany
| | - Sandra C Cifuentes
- Departamento de Ciencia e Ingeniería de Materiales e Ingeniería Química, IAAB, Universidad Carlos III de Madrid, Avda. de la Universidad, 30, 28911 Leganés, Madrid Spain
| | - Cornelius von Wilmowsky
- Department of Oral and Maxillofacial Surgery, University Hospital Erlangen, Glueckstrasse 11, 91054 Erlangen, Germany
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53
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Koutsoukis T, Zinelis S, Eliades G, Al-Wazzan K, Rifaiy MA, Al Jabbari YS. Selective Laser Melting Technique of Co-Cr Dental Alloys: A Review of Structure and Properties and Comparative Analysis with Other Available Techniques. J Prosthodont 2017; 24:303-12. [PMID: 26129918 DOI: 10.1111/jopr.12268] [Citation(s) in RCA: 172] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/03/2014] [Indexed: 11/27/2022] Open
Abstract
PURPOSE The aim of this study was to review the effect of selective laser melting (SLM) procedure on the properties of dental structures made of Co-Cr alloys and to evaluate its quality and compare it to those produced by conventional casting and milling fabrication techniques. MATERIALS AND METHODS A computerized database search using PubMed and Scopus was conducted for peer-reviewed scientific research studies regarding the use of SLM in Co-Cr dental alloys with no restrictions for publication years. The search engines provided hundreds of results, and only 48 scientific research papers, case studies, or literature reviews were considered relevant for this review. RESULTS The innovative manufacturing concept of SLM offers many advantages compared with casting and milling fabrication techniques. SLM provides different microstructure from casting and milling with minimal internal porosity and internal fitting, marginal adaptation, and comparable bond strength to porcelain. Mechanical and electrochemical properties of SLM structures are enhanced compared to cast, while clinical longevity of single-metal ceramic crowns is comparable to Au-Pt dental alloy. CONCLUSION The SLM technique provides dental prosthetic restorations more quickly and less expensively without compromising their quality compared with restorations prepared by casting and milling techniques. CLINICAL SIGNIFICANCE The current SLM devices provide metallic restorations made of Co-Cr alloys for removable and fixed partial dentures without compromising the alloy or restoration properties at a fraction of the time and cost, showing great potential to replace the aforementioned fabrication techniques in the long term; however, further clinical studies are essential to increase the acceptance of this technology by the worldwide dental community.
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Affiliation(s)
- Theodoros Koutsoukis
- Dental Biomaterials Research and Development Chair, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Spiros Zinelis
- Dental Biomaterials Research and Development Chair, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.,Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Athens, Greece
| | - George Eliades
- Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Athens, Greece
| | - Khalid Al-Wazzan
- Dental Biomaterials Research and Development Chair, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.,Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Mohammed Al Rifaiy
- Dental Biomaterials Research and Development Chair, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.,Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Youssef S Al Jabbari
- Dental Biomaterials Research and Development Chair, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.,Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
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54
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A custom-made temporomandibular joint prosthesis for fabrication by selective laser melting: Finite element analysis. Med Eng Phys 2017. [DOI: 10.1016/j.medengphy.2017.04.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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55
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Prasad K, Bazaka O, Chua M, Rochford M, Fedrick L, Spoor J, Symes R, Tieppo M, Collins C, Cao A, Markwell D, Ostrikov KK, Bazaka K. Metallic Biomaterials: Current Challenges and Opportunities. MATERIALS (BASEL, SWITZERLAND) 2017; 10:E884. [PMID: 28773240 PMCID: PMC5578250 DOI: 10.3390/ma10080884] [Citation(s) in RCA: 203] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 07/14/2017] [Accepted: 07/25/2017] [Indexed: 11/16/2022]
Abstract
Metallic biomaterials are engineered systems designed to provide internal support to biological tissues and they are being used largely in joint replacements, dental implants, orthopaedic fixations and stents. Higher biomaterial usage is associated with an increased incidence of implant-related complications due to poor implant integration, inflammation, mechanical instability, necrosis and infections, and associated prolonged patient care, pain and loss of function. In this review, we will briefly explore major representatives of metallic biomaterials along with the key existing and emerging strategies for surface and bulk modification used to improve biointegration, mechanical strength and flexibility of biometals, and discuss their compatibility with the concept of 3D printing.
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Affiliation(s)
- Karthika Prasad
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia.
- CSIRO-QUT Joint Sustainable Processes and Devices Laboratory, Commonwealth Scientific and Industrial Research Organization, P.O. Box 218, Lindfield, NSW 2070, Australia.
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD 4000, Australia.
| | - Olha Bazaka
- College of Science and Engineering, Technology and Engineering, James Cook University, Townsville, QLD 4810, Australia.
| | - Ming Chua
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia.
| | - Madison Rochford
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia.
| | - Liam Fedrick
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia.
| | - Jordan Spoor
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia.
| | - Richard Symes
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia.
| | - Marcus Tieppo
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia.
| | - Cameron Collins
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia.
| | - Alex Cao
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia.
| | - David Markwell
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia.
| | - Kostya Ken Ostrikov
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia.
- CSIRO-QUT Joint Sustainable Processes and Devices Laboratory, Commonwealth Scientific and Industrial Research Organization, P.O. Box 218, Lindfield, NSW 2070, Australia.
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD 4000, Australia.
| | - Kateryna Bazaka
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia.
- CSIRO-QUT Joint Sustainable Processes and Devices Laboratory, Commonwealth Scientific and Industrial Research Organization, P.O. Box 218, Lindfield, NSW 2070, Australia.
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD 4000, Australia.
- College of Science and Engineering, Technology and Engineering, James Cook University, Townsville, QLD 4810, Australia.
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Cox SC, Jamshidi P, Eisenstein NM, Webber MA, Burton H, Moakes RJA, Addison O, Attallah M, Shepherd DE, Grover LM. Surface Finish has a Critical Influence on Biofilm Formation and Mammalian Cell Attachment to Additively Manufactured Prosthetics. ACS Biomater Sci Eng 2017; 3:1616-1626. [DOI: 10.1021/acsbiomaterials.7b00336] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
| | | | - Neil M. Eisenstein
- Royal Centre for Defence Medicine, Birmingham Research Park, Vincent Drive, Edgbaston B15 2SQ, United Kingdom
| | - Mark A. Webber
- Institute of Food Research, Norwich
Research Park, Norwich NR4 7UG, United Kingdom
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Histologic and Histomorphometric Comparison of Bone Regeneration Between Bone Morphogenetic Protein-2 and Platelet-Derived Growth Factor-BB in Experimental Groups. J Craniofac Surg 2017; 27:805-9. [PMID: 27092911 DOI: 10.1097/scs.0000000000002560] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2) and recombinant human platelet-derived growth factor-BB (rhPDGF-BB) delivered via absorbable collagen sponge (ACS) on bone formation was evaluated in guinea pig tibias. Three-millimeter-circular bone tibia defects were created in 24 guinea pigs assigned randomly to 4 groups according to the following defect filling materials: ACS only, rhBMP-2+ACS, rhPDGF-BB+ACS, or empty. New bone formation was evaluated histologically and histomorphometrically at 15 (early healing) and 45 days (late healing). Mean new bone per total defect area ratio was 0.73, 0.57, 0.43, and 0.42 in rhBMP-2+ACS, rhPDGF-BB+ACS, ACS only, and empty groups at early healing, respectively. During early healing, significantly more new bone formation was observed in rhBMP-2+ACS and rhPDGF-BB+ACS groups than in the control groups. New bone formation was significantly higher with rhBMP-2+ACS than with rhPDGF-BB+ACS. Mean new bone per total defect area ratio was 0.81, 0.86, 0.74, and 0.75 in the rhBMP-2+ACS, rhPDGF-BB+ACS, ACS only, and empty groups at late healing, respectively. During late healing, new bone formation was significantly higher in the rhPDGF-BB+ACS group relative to both control groups, but the results did not differ significantly from those in the rhBMP-2+ACS group. New bone formation in the rhBMP-2+ACS group did not change significantly between the healing periods. In the rhPDGF-BB+ACS group, however, new bone formation was significantly higher in the late healing period. Both growth factors accelerated new bone formation in the early healing period. Although rhBMP-2 was more effective in the early healing period, the effects of rhPDGF-BB were longer lasting.
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58
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Tan XP, Tan YJ, Chow CSL, Tor SB, Yeong WY. Metallic powder-bed based 3D printing of cellular scaffolds for orthopaedic implants: A state-of-the-art review on manufacturing, topological design, mechanical properties and biocompatibility. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2017; 76:1328-1343. [PMID: 28482501 DOI: 10.1016/j.msec.2017.02.094] [Citation(s) in RCA: 157] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 02/21/2017] [Indexed: 01/15/2023]
Abstract
Metallic cellular scaffold is one of the best choices for orthopaedic implants as a replacement of human body parts, which could improve life quality and increase longevity for the people needed. Unlike conventional methods of making cellular scaffolds, three-dimensional (3D) printing or additive manufacturing opens up new possibilities to fabricate those customisable intricate designs with highly interconnected pores. In the past decade, metallic powder-bed based 3D printing methods emerged and the techniques are becoming increasingly mature recently, where selective laser melting (SLM) and selective electron beam melting (SEBM) are the two representatives. Due to the advantages of good dimensional accuracy, high build resolution, clean build environment, saving materials, high customisability, etc., SLM and SEBM show huge potential in direct customisable manufacturing of metallic cellular scaffolds for orthopaedic implants. Ti-6Al-4V to date is still considered to be the optimal materials for producing orthopaedic implants due to its best combination of biocompatibility, corrosion resistance and mechanical properties. This paper presents a state-of-the-art overview mainly on manufacturing, topological design, mechanical properties and biocompatibility of cellular Ti-6Al-4V scaffolds via SLM and SEBM methods. Current manufacturing limitations, topological shortcomings, uncertainty of biocompatible test were sufficiently discussed herein. Future perspectives and recommendations were given at the end.
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Affiliation(s)
- X P Tan
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.
| | - Y J Tan
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
| | - C S L Chow
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
| | - S B Tor
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
| | - W Y Yeong
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
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59
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Zhang XY, Fang G, Zhou J. Additively Manufactured Scaffolds for Bone Tissue Engineering and the Prediction of their Mechanical Behavior: A Review. MATERIALS 2017; 10:ma10010050. [PMID: 28772411 PMCID: PMC5344607 DOI: 10.3390/ma10010050] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 12/20/2016] [Accepted: 12/22/2016] [Indexed: 12/15/2022]
Abstract
Additive manufacturing (AM), nowadays commonly known as 3D printing, is a revolutionary materials processing technology, particularly suitable for the production of low-volume parts with high shape complexities and often with multiple functions. As such, it holds great promise for the fabrication of patient-specific implants. In recent years, remarkable progress has been made in implementing AM in the bio-fabrication field. This paper presents an overview on the state-of-the-art AM technology for bone tissue engineering (BTE) scaffolds, with a particular focus on the AM scaffolds made of metallic biomaterials. It starts with a brief description of architecture design strategies to meet the biological and mechanical property requirements of scaffolds. Then, it summarizes the working principles, advantages and limitations of each of AM methods suitable for creating porous structures and manufacturing scaffolds from powdered materials. It elaborates on the finite-element (FE) analysis applied to predict the mechanical behavior of AM scaffolds, as well as the effect of the architectural design of porous structure on its mechanical properties. The review ends up with the authors’ view on the current challenges and further research directions.
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Affiliation(s)
- Xiang-Yu Zhang
- Department of Mechanical Engineering, Tsinghua University, Beijing 10004, China.
| | - Gang Fang
- Department of Mechanical Engineering, Tsinghua University, Beijing 10004, China.
- State Key Laboratory of Tribology, Beijing 100084, China.
| | - Jie Zhou
- Department of Biomechanical Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
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60
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A technique for evaluating bone ingrowth into 3D printed, porous Ti6Al4V implants accurately using X-ray micro-computed tomography and histomorphometry. Micron 2016; 94:1-8. [PMID: 27960108 DOI: 10.1016/j.micron.2016.11.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 11/18/2016] [Accepted: 11/18/2016] [Indexed: 01/10/2023]
Abstract
This paper investigates the application of X-ray micro-computed tomography (micro-CT) to accurately evaluate bone formation within 3D printed, porous Ti6Al4V implants manufactured using Electron Beam Melting (EBM), retrieved after six months of healing in sheep femur and tibia. All samples were scanned twice (i.e., before and after resin embedding), using fast, low-resolution scans (Skyscan 1172; Bruker micro-CT, Kontich, Belgium), and were analysed by 2D and 3D morphometry. The main questions posed were: (i) Can low resolution, fast scans provide morphometric data of bone formed inside (and around) metal implants with a complex, open-pore architecture?, (ii) Can micro-CT be used to accurately quantify both the bone area (BA) and bone-implant contact (BIC)?, (iii) What degree of error is introduced in the quantitative data by varying the threshold values?, and (iv) Does resin embedding influence the accuracy of the analysis? To validate the accuracy of micro-CT measurements, each data set was correlated with a corresponding centrally cut histological section. The results show that quantitative histomorphometry corresponds strongly with 3D measurements made by micro-CT, where a high correlation exists between the two techniques for bone area/volume measurements around and inside the porous network. On the contrary, the direct bone-implant contact is challenging to estimate accurately or reproducibly. Large errors may be introduced in micro-CT measurements when segmentation is performed without calibrating the data set against a corresponding histological section. Generally, the bone area measurement is strongly influenced by the lower threshold limit, while the upper threshold limit has little or no effect. Resin embedding does not compromise the accuracy of micro-CT measurements, although there is a change in the contrast distributions and optimisation of the threshold ranges is required.
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Suska F, Kjeller G, Tarnow P, Hryha E, Nyborg L, Snis A, Palmquist A. Electron Beam Melting Manufacturing Technology for Individually Manufactured Jaw Prosthesis: A Case Report. J Oral Maxillofac Surg 2016; 74:1706.e1-1706.e15. [DOI: 10.1016/j.joms.2016.03.046] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 03/28/2016] [Accepted: 03/31/2016] [Indexed: 01/26/2023]
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Xiu P, Jia Z, Lv J, Yin C, Cheng Y, Zhang K, Song C, Leng H, Zheng Y, Cai H, Liu Z. Tailored Surface Treatment of 3D Printed Porous Ti6Al4V by Microarc Oxidation for Enhanced Osseointegration via Optimized Bone In-Growth Patterns and Interlocked Bone/Implant Interface. ACS APPLIED MATERIALS & INTERFACES 2016; 8:17964-17975. [PMID: 27341499 DOI: 10.1021/acsami.6b05893] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
3D printed porous titanium (Ti) holds enormous potential for load-bearing orthopedic applications. Although the 3D printing technique has good control over the macro-sturctures of porous Ti, the surface properties that affect tissue response are beyond its control, adding the need for tailored surface treatment to improve its osseointegration capacity. Here, the one step microarc oxidation (MAO) process was applied to a 3D printed porous Ti6Al4V (Ti64) scaffold to endow the scaffold with a homogeneous layer of microporous TiO2 and significant amounts of amorphous calcium-phosphate. Following the treatment, the porous Ti64 scaffolds exhibited a drastically improved apatite forming ability, cyto-compatibility, and alkaline phosphatase activity. In vivo test in a rabbit model showed that the bone in-growth at the untreated scaffold was in a pattern of distance osteogenesis by which bone formed only at the periphery of the scaffold. In contrast, the bone in-growth at the MAO-treated scaffold exhibited a pattern of contact osteogenesis by which bone formed in situ on the entire surface of the scaffold. This pattern of bone in-growth significantly increased bone formation both in and around the scaffold possibly through enhancement of bone formation and disruption of bone remodeling. Moreover, the implant surface of the MAO-treated scaffold interlocked with the bone tissues through the fabricated microporous topographies to generate a stronger bone/implant interface. The increased osteoinetegration strength was further proven by a push out test. MAO exhibits a high efficiency in the enhancement of osteointegration of porous Ti64 via optimizing the patterns of bone in-growth and bone/implant interlocking. Therefore, post-treatment of 3D printed porous Ti64 with MAO technology might open up several possibilities for the development of bioactive customized implants in orthopedic applications.
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Affiliation(s)
- Peng Xiu
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
| | - Zhaojun Jia
- Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University , Beijing 100871, People's Republic of China
| | - Jia Lv
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
| | - Chuan Yin
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
| | - Yan Cheng
- Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University , Beijing 100871, People's Republic of China
| | - Ke Zhang
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
| | - Chunli Song
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
| | - Huijie Leng
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
| | - Yufeng Zheng
- Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University , Beijing 100871, People's Republic of China
- Department of Materials Science and Engineering, College of Engineering, Peking University , Beijing 100871, People's Republic of China
| | - Hong Cai
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
| | - Zhongjun Liu
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
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Schouman T, Schmitt M, Adam C, Dubois G, Rouch P. Influence of the overall stiffness of a load-bearing porous titanium implant on bone ingrowth in critical-size mandibular bone defects in sheep. J Mech Behav Biomed Mater 2016; 59:484-496. [DOI: 10.1016/j.jmbbm.2016.02.036] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 02/21/2016] [Accepted: 02/28/2016] [Indexed: 11/30/2022]
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64
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Cheng A, Humayun A, Boyan BD, Schwartz Z. Enhanced Osteoblast Response to Porosity and Resolution of Additively Manufactured Ti-6Al-4V Constructs with Trabeculae-Inspired Porosity. 3D PRINTING AND ADDITIVE MANUFACTURING 2016; 3:10-21. [PMID: 28804735 PMCID: PMC4981154 DOI: 10.1089/3dp.2015.0038] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The addition of porosity to the traditionally used solid titanium metal implants has been suggested to more closely mimic the natural mechanical properties of bone and increase osseointegration in dental and orthopedic implants. The objective of this study was to evaluate cellular response to three-dimensional (3D) porous Ti-6Al-4V constructs fabricated by additive manufacturing using laser sintering with low porosity (LP), medium porosity (MP), and high porosity (HP) with low resolution (LR) and high resolution (HR) based on a computed tomography scan of human trabecular bone. After surface processing, construct porosity ranged from 41.0% to 76.1%, but all possessed micro-/nanoscale surface roughness and similar surface chemistry containing mostly Ti, O, and C. Biological responses (osteoblast differentiation, maturation, and local factor production) by MG63 osteoblast-like cells and normal human osteoblasts favored 3D than two-dimensional (2D) solid constructs. First, MG63 cells were used to assess differences in cell response to 2D compared to LR and HR porous 3D constructs. MG63 cells were sensitive to porosity resolution and exhibited increased osteocalcin (OCN), vascular endothelial growth factor (VEGF), osteoprotegerin (OPG), and bone morphogenetic protein 2 (BMP2) on HR 3D constructs than on 2D and LR 3D constructs. MG63 cells also exhibited porosity-dependent responses on HR constructs, with up to a 6.9-fold increase in factor production on LP-HR and MP-HR constructs than on HP-HR constructs. NHOsts were then used to validate biological response on HR constructs. NHOsts exhibited decreased DNA content and alkaline phosphatase activity and up to a 2.9-fold increase in OCN, OPG, VEGF, BMP2, and BMP4 on 3D HR constructs than on 2D controls. These results indicate that osteoblasts prefer a 3D architecture than a 2D surface and that osteoblasts are sensitive to the resolution of trabecular detail and porosity parameters of laser-sintered 3D Ti-6Al-4V constructs.
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Affiliation(s)
- Alice Cheng
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia
- Department of Biomedical Engineering, Emory University, Atlanta, Georgia
- Department of Biomedical Engineering, Peking University, Beijing, China
| | - Aiza Humayun
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia
| | - Barbara D. Boyan
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia
| | - Zvi Schwartz
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia
- Department of Periodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas
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65
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Zargarian A, Esfahanian M, Kadkhodapour J, Ziaei-Rad S. Numerical simulation of the fatigue behavior of additive manufactured titanium porous lattice structures. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 60:339-347. [DOI: 10.1016/j.msec.2015.11.054] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 11/10/2015] [Accepted: 11/20/2015] [Indexed: 01/05/2023]
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66
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Sing SL, An J, Yeong WY, Wiria FE. Laser and electron-beam powder-bed additive manufacturing of metallic implants: A review on processes, materials and designs. J Orthop Res 2016; 34:369-85. [PMID: 26488900 DOI: 10.1002/jor.23075] [Citation(s) in RCA: 231] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 10/16/2015] [Indexed: 02/04/2023]
Abstract
Additive manufacturing (AM), also commonly known as 3D printing, allows the direct fabrication of functional parts with complex shapes from digital models. In this review, the current progress of two AM processes suitable for metallic orthopaedic implant applications, namely selective laser melting (SLM) and electron beam melting (EBM) are presented. Several critical design factors such as the need for data acquisition for patient-specific design, design dependent porosity for osteo-inductive implants, surface topology of the implants and design for reduction of stress-shielding in implants are discussed. Additive manufactured biomaterials such as 316L stainless steel, titanium-6aluminium-4vanadium (Ti6Al4V) and cobalt-chromium (CoCr) are highlighted. Limitations and future potential of such technologies are also explored.
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Affiliation(s)
- Swee Leong Sing
- SIMTech-NTU Joint Laboratory (3D Additive Manufacturing), Nanyang Technological University, HW3-01-01, 65A Nanyang Drive, Singapore 637333.,Singapore Centre for 3D Printing, School of Mechanical & Aerospace Engineering, Nanyang Technological University, HW1-01-05, 2A Nanyang Link, Singapore 637372
| | - Jia An
- Singapore Centre for 3D Printing, School of Mechanical & Aerospace Engineering, Nanyang Technological University, HW1-01-05, 2A Nanyang Link, Singapore 637372
| | - Wai Yee Yeong
- SIMTech-NTU Joint Laboratory (3D Additive Manufacturing), Nanyang Technological University, HW3-01-01, 65A Nanyang Drive, Singapore 637333.,Singapore Centre for 3D Printing, School of Mechanical & Aerospace Engineering, Nanyang Technological University, HW1-01-05, 2A Nanyang Link, Singapore 637372
| | - Florencia Edith Wiria
- SIMTech-NTU Joint Laboratory (3D Additive Manufacturing), Nanyang Technological University, HW3-01-01, 65A Nanyang Drive, Singapore 637333.,Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, Singapore 638075
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67
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Effects of Osseointegration by Bone Morphogenetic Protein-2 on Titanium Implants In Vitro and In Vivo. Bioinorg Chem Appl 2016; 2016:3837679. [PMID: 26977141 PMCID: PMC4761669 DOI: 10.1155/2016/3837679] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 12/22/2015] [Indexed: 01/18/2023] Open
Abstract
This study designed a biomimetic implant for reducing healing time and achieving early osseointegration to create an active surface. Bone morphogenetic protein-2 (BMP-2) is a strong regulator protein in osteogenic pathways. Due to hardly maintaining BMP-2 biological function and specificity, BMP-2 efficient delivery on implant surfaces is the main challenge for the clinic application. In this study, a novel method for synthesizing functionalized silane film for superior modification with BMP-2 on titanium surfaces is proposed. Three groups were compared with and without BMP-2 on modified titanium surfaces in vitro and in vivo: mechanical grinding; electrochemical modification through potentiostatic anodization (ECH); and sandblasting, alkali heating, and etching (SMART). Cell tests indicated that the ECH and SMART groups with BMP-2 markedly promoted D1 cell activity and differentiation compared with the groups without BMP-2. Moreover, the SMART group with a BMP-2 surface markedly promoted early alkaline phosphatase expression in the D1 cells compared with the other surface groups. Compared with these groups in vivo, SMART silaning with BMP-2 showed superior bone quality and created contact areas between implant and surrounding bones. The SMART group with BMP-2 could promote cell mineralization in vitro and osseointegration in vivo, indicating potential clinical use.
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68
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Jardini A, Larosa M, Macedo M, Bernardes L, Lambert C, Zavaglia C, Filho RM, Calderoni D, Ghizoni E, Kharmandayan P. Improvement in Cranioplasty: Advanced Prosthesis Biomanufacturing. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.procir.2015.11.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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69
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Fan H, Fu J, Li X, Pei Y, Li X, Pei G, Guo Z. Implantation of customized 3-D printed titanium prosthesis in limb salvage surgery: a case series and review of the literature. World J Surg Oncol 2015; 13:308. [PMID: 26537339 PMCID: PMC4632365 DOI: 10.1186/s12957-015-0723-2] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 10/26/2015] [Indexed: 11/25/2022] Open
Abstract
Background Although modular prosthesis is commercially available to meet requirements in most limb salvage surgeries, customized prosthesis is still needed. In contrast to traditional complicated procedures, rapid prototyping (RP) technique can directly manufacture customized titanium prosthesis. The objectives of this study were to describe the workflow of this technique and show the follow-up results of patients. Methods Three patients with clavicle Ewing’s sarcoma (ES), scapular ES, and pelvic chondrosarcoma (CS) were scanned by computer tomography (CT). The images were segmented and reconstructed for preoperative planning and prosthesis design. Then, the data of prosthesis were imported into an electron beam melting system to manufacture implants. These three patients received prosthesis implantation after tumor excision. They were followed up to evaluate survival rate, functional outcome, and complications. Results All patients were alive with no evidence of disease. The Musculoskeletal Tumor Society (MSTS) scores were 93, 73, and 90 % for patients with clavicle ES, scapular ES, and pelvic CS, respectively. No surgical complications including limb length discrepancy, screw loosening, and implant breakage were observed in current study. Conclusions Electron beam melting (EBM) is a useful method to directly manufacture customized titanium prostheses. It might improve the effectiveness of limb salvage surgery for sarcomas in unusual sites.
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Affiliation(s)
- Hongbin Fan
- Department of Orthopaedic Surgery, Xi-Jing Hospital, Fourth Military Medical University, West Chang-le Road, Xi'an, 710032, China.
| | - Jun Fu
- Department of Orthopaedic Surgery, Xi-Jing Hospital, Fourth Military Medical University, West Chang-le Road, Xi'an, 710032, China.
| | - Xiangdong Li
- Department of Orthopaedic Surgery, Xi-Jing Hospital, Fourth Military Medical University, West Chang-le Road, Xi'an, 710032, China.
| | - Yanjun Pei
- Department of Orthopaedic Surgery, Xi-Jing Hospital, Fourth Military Medical University, West Chang-le Road, Xi'an, 710032, China.
| | - Xiaokang Li
- Department of Orthopaedic Surgery, Xi-Jing Hospital, Fourth Military Medical University, West Chang-le Road, Xi'an, 710032, China.
| | - Guoxian Pei
- Department of Orthopaedic Surgery, Xi-Jing Hospital, Fourth Military Medical University, West Chang-le Road, Xi'an, 710032, China.
| | - Zheng Guo
- Department of Orthopaedic Surgery, Xi-Jing Hospital, Fourth Military Medical University, West Chang-le Road, Xi'an, 710032, China.
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70
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Bonda DJ, Manjila S, Selman WR, Dean D. The Recent Revolution in the Design and Manufacture of Cranial Implants: Modern Advancements and Future Directions. Neurosurgery 2015; 77:814-24; discussion 824. [PMID: 26171578 PMCID: PMC4615389 DOI: 10.1227/neu.0000000000000899] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Large format (i.e., >25 cm) cranioplasty is a challenging procedure not only from a cosmesis standpoint, but also in terms of ensuring that the patient's brain will be well-protected from direct trauma. Until recently, when a patient's own cranial flap was unavailable, these goals were unattainable. Recent advances in implant computer-aided design and 3-dimensional (3-D) printing are leveraging other advances in regenerative medicine. It is now possible to 3-D-print patient-specific implants from a variety of polymer, ceramic, or metal components. A skull template may be used to design the external shape of an implant that will become well integrated in the skull, while also providing beneficial distribution of mechanical force in the event of trauma. Furthermore, an internal pore geometry can be utilized to facilitate the seeding of banked allograft cells. Implants may be cultured in a bioreactor along with recombinant growth factors to produce implants coated with bone progenitor cells and extracellular matrix that appear to the body as a graft, albeit a tissue-engineered graft. The growth factors would be left behind in the bioreactor and the graft would resorb as new host bone invades the space and is remodeled into strong bone. As we describe in this review, such advancements will lead to optimal replacement of cranial defects that are both patient-specific and regenerative.
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Affiliation(s)
- David J. Bonda
- Department of Neurological Surgery, University Hospitals Case Medical Center, 10900 Euclid Avenue, Cleveland, OH 44106
| | - Sunil Manjila
- Department of Neurological Surgery, University Hospitals Case Medical Center, 10900 Euclid Avenue, Cleveland, OH 44106
| | - Warren R. Selman
- Department of Neurological Surgery, University Hospitals Case Medical Center, 10900 Euclid Avenue, Cleveland, OH 44106
| | - David Dean
- Department of Plastic Surgery, The Ohio State University, 460 West 12th Ave., 10th Floor, Rm. 1004, Columbus, OH 43210
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71
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Titanium-Based Hip Stems with Drug Delivery Functionality through Additive Manufacturing. BIOMED RESEARCH INTERNATIONAL 2015; 2015:134093. [PMID: 26504776 PMCID: PMC4609336 DOI: 10.1155/2015/134093] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 08/14/2015] [Accepted: 08/16/2015] [Indexed: 11/17/2022]
Abstract
Postoperative infections are a major concern in patients that receive implants. These infections generally occur in areas with poor blood flow and pathogens do not always respond to antibiotic treatment. With the latest developments in nanotechnology, the incorporation of antibiotics into prosthetic implants may soon become a standard procedure. The success will, however, depend on the ability to control the release of antibiotics at concentrations high enough to prevent the development of antibiotic-resistant strains. Through additive manufacturing, antibiotics can be incorporated into cementless femoral stems to produce prosthetic devices with antimicrobial properties. With the emerging increase in resistance to antibiotics, the incorporation of antimicrobial compounds other than antibiotics, preferably drugs with a broader spectrum of antimicrobial activity, will have to be explored. This review highlights the microorganisms associated with total hip arthroplasty (THA), discusses the advantages and disadvantages of the latest materials used in hip implants, compares different antimicrobial agents that could be incorporated, and addresses novel ideas for future research.
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72
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Effects of rhBMP-2 on Sandblasted and Acid Etched Titanium Implant Surfaces on Bone Regeneration and Osseointegration: Spilt-Mouth Designed Pilot Study. BIOMED RESEARCH INTERNATIONAL 2015; 2015:459393. [PMID: 26504807 PMCID: PMC4609358 DOI: 10.1155/2015/459393] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 07/14/2015] [Accepted: 07/15/2015] [Indexed: 12/20/2022]
Abstract
This study was conducted to evaluate effects of rhBMP-2 applied at different concentrations to sandblasted and acid etched (SLA) implants on osseointegration and bone regeneration in a bone defect of beagle dogs as pilot study using split-mouth design. Methods. For experimental groups, SLA implants were coated with different concentrations of rhBMP-2 (0.1, 0.5, and 1 mg/mL). After assessment of surface characteristics and rhBMP-2 releasing profile, the experimental groups and untreated control groups (n = 6 in each group, two animals in each group) were placed in split-mouth designed animal models with buccal open defect. At 8 weeks after implant placement, implant stability quotients (ISQ) values were recorded and vertical bone height (VBH, mm), bone-to-implant contact ratio (BIC, %), and bone volume (BV, %) in the upper 3 mm defect areas were measured. Results. The ISQ values were highest in the 1.0 group. Mean values of VBH (mm), BIC (%), and BV (%) were greater in the 0.5 mg/mL and 1.0 mg/mL groups than those in 0.1 and control groups in buccal defect areas. Conclusion. In the open defect area surrounding the SLA implant, coating with 0.5 and 1.0 mg/mL concentrations of rhBMP-2 was more effective, compared with untreated group, in promoting bone regeneration and osseointegration.
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73
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Guo M, Li X. Development of porous Ti6Al4V/chitosan sponge composite scaffold for orthopedic applications. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2015; 58:1177-81. [PMID: 26478418 DOI: 10.1016/j.msec.2015.09.061] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 08/21/2015] [Accepted: 09/14/2015] [Indexed: 12/18/2022]
Abstract
A novel composite scaffold consisting of porous Ti6Al4V part filled with chitosan sponge was fabricated using a combination of electron beam melting and freeze-drying. The mechanical properties of porous Ti6Al4V part were examined via compressive test. The ultimate compressive strength was 85.35 ± 8.68 MPa and the compressive modulus was 2.26 ± 0.42 GPa. The microstructure of composite scaffold was characterized using scanning electron microscopy. The chitosan sponge filled in Ti6Al4V part exhibited highly porous and well-interconnected micro-pore architecture. The osteoblastic cells were seeded on scaffolds to test their seeding efficiency and biocompatibility. Significantly higher cell seeding efficiency was found on composite scaffold. The biological response of osteoblasts on composite scaffolds was superior in terms of improved cell attachment, higher proliferation, and well-spread morphology in relation to porous Ti6Al4V part. These results suggest that the Ti6Al4V/chitosan composite scaffold is potentially useful as a biomedical scaffold for orthopedic applications.
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Affiliation(s)
- Miao Guo
- College of Life Information Science & Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Xiang Li
- School of Mechanical Engineering, Shanghai Jiao Tong University, State Key Laboratory of Mechanical System and Vibration, Shanghai 200240, China.
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74
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Ahmadi SM, Yavari SA, Wauthle R, Pouran B, Schrooten J, Weinans H, Zadpoor AA. Additively Manufactured Open-Cell Porous Biomaterials Made from Six Different Space-Filling Unit Cells: The Mechanical and Morphological Properties. MATERIALS 2015; 8:1871-1896. [PMID: 28788037 PMCID: PMC5507048 DOI: 10.3390/ma8041871] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Revised: 04/08/2015] [Accepted: 04/14/2015] [Indexed: 01/02/2023]
Abstract
It is known that the mechanical properties of bone-mimicking porous biomaterials are a function of the morphological properties of the porous structure, including the configuration and size of the repeating unit cell from which they are made. However, the literature on this topic is limited, primarily because of the challenge in fabricating porous biomaterials with arbitrarily complex morphological designs. In the present work, we studied the relationship between relative density (RD) of porous Ti6Al4V EFI alloy and five compressive properties of the material, namely elastic gradient or modulus (Es20–70), first maximum stress, plateau stress, yield stress, and energy absorption. Porous structures with different RD and six different unit cell configurations (cubic (C), diamond (D), truncated cube (TC), truncated cuboctahedron (TCO), rhombic dodecahedron (RD), and rhombicuboctahedron (RCO)) were fabricated using selective laser melting. Each of the compressive properties increased with increase in RD, the relationship being of a power law type. Clear trends were seen in the influence of unit cell configuration and porosity on each of the compressive properties. For example, in terms of Es20–70, the structures may be divided into two groups: those that are stiff (comprising those made using C, TC, TCO, and RCO unit cell) and those that are compliant (comprising those made using D and RD unit cell).
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Affiliation(s)
- Seyed Mohammad Ahmadi
- Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft, The Netherlands.
| | - Saber Amin Yavari
- Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft, The Netherlands.
- Department of Orthopedics and Department of Rheumatology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
| | | | - Behdad Pouran
- Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft, The Netherlands.
- Department of Orthopedics and Department of Rheumatology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
| | - Jan Schrooten
- Department of Metallurgy and Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, PB 2450, 3001 Leuven, Belgium.
| | - Harrie Weinans
- Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft, The Netherlands.
- Department of Orthopedics and Department of Rheumatology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
| | - Amir A Zadpoor
- Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft, The Netherlands.
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75
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Biomechanical stability of novel mechanically adapted open-porous titanium scaffolds in metatarsal bone defects of sheep. Biomaterials 2015; 46:35-47. [DOI: 10.1016/j.biomaterials.2014.12.010] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 11/26/2014] [Accepted: 12/16/2014] [Indexed: 11/23/2022]
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76
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Abstract
A review of how the geometrical design of scaffolds influences the bone tissue regeneration process.
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Affiliation(s)
- Amir A. Zadpoor
- Department of Biomechanical Engineering
- Faculty of Mechanical
- Maritime
- and Materials Engineering
- Delft University of Technology (TU Delft)
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77
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Sidambe AT. Biocompatibility of Advanced Manufactured Titanium Implants-A Review. MATERIALS (BASEL, SWITZERLAND) 2014; 7:8168-8188. [PMID: 28788296 PMCID: PMC5456424 DOI: 10.3390/ma7128168] [Citation(s) in RCA: 231] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 10/05/2014] [Accepted: 12/08/2014] [Indexed: 11/16/2022]
Abstract
Titanium (Ti) and its alloys may be processed via advanced powder manufacturing routes such as additive layer manufacturing (or 3D printing) or metal injection moulding. This field is receiving increased attention from various manufacturing sectors including the medical devices sector. It is possible that advanced manufacturing techniques could replace the machining or casting of metal alloys in the manufacture of devices because of associated advantages that include design flexibility, reduced processing costs, reduced waste, and the opportunity to more easily manufacture complex or custom-shaped implants. The emerging advanced manufacturing approaches of metal injection moulding and additive layer manufacturing are receiving particular attention from the implant fabrication industry because they could overcome some of the difficulties associated with traditional implant fabrication techniques such as titanium casting. Using advanced manufacturing, it is also possible to produce more complex porous structures with improved mechanical performance, potentially matching the modulus of elasticity of local bone. While the economic and engineering potential of advanced manufacturing for the manufacture of musculo-skeletal implants is therefore clear, the impact on the biocompatibility of the materials has been less investigated. In this review, the capabilities of advanced powder manufacturing routes in producing components that are suitable for biomedical implant applications are assessed with emphasis placed on surface finishes and porous structures. Given that biocompatibility and host bone response are critical determinants of clinical performance, published studies of in vitro and in vivo research have been considered carefully. The review concludes with a future outlook on advanced Ti production for biomedical implants using powder metallurgy.
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Affiliation(s)
- Alfred T Sidambe
- Bioengineering & Health Technologies Group, School of Clinical Dentistry, University of Sheffield, 19 Claremont Crescent, Sheffield S10 2TA, UK.
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78
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Improving osteoblast functions and bone formation upon BMP-2 immobilization on titanium modified with heparin. Carbohydr Polym 2014; 114:123-132. [DOI: 10.1016/j.carbpol.2014.08.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 08/04/2014] [Accepted: 08/05/2014] [Indexed: 12/21/2022]
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79
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Wieding J, Wolf A, Bader R. Numerical optimization of open-porous bone scaffold structures to match the elastic properties of human cortical bone. J Mech Behav Biomed Mater 2014; 37:56-68. [DOI: 10.1016/j.jmbbm.2014.05.002] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 04/29/2014] [Accepted: 05/03/2014] [Indexed: 10/25/2022]
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80
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Calderoni DR, Gilioli R, Munhoz ALJ, Maciel Filho R, Zavaglia CADC, Lambert CS, Lopes ÉSN, Toro IFC, Kharmandayan P. Paired evaluation of calvarial reconstruction with prototyped titanium implants with and without ceramic coating. Acta Cir Bras 2014; 29:579-87. [DOI: 10.1590/s0102-8650201400150005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 07/23/2014] [Indexed: 11/21/2022] Open
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81
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Luthringer BJC, Ali F, Akaichi H, Feyerabend F, Ebel T, Willumeit R. Production, characterisation, and cytocompatibility of porous titanium-based particulate scaffolds. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2013; 24:2337-2358. [PMID: 23807315 DOI: 10.1007/s10856-013-4989-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 06/14/2013] [Indexed: 06/02/2023]
Abstract
Despite its non-matching mechanical properties titanium remains the preferred metal implant material in orthopaedics. As a consequence in some cases stress shielding effect occurs, leading to implant loosening, osteopenia, and finally revision surgery. Porous metal scaffolds to allow easier specialised cells ingrowth with mechanical properties closer to the ones of bone can overcome this problem. This should improve healing processes, implant integration, and dynamic strength of implants retaining. Three Ti-6Al-4V materials were metal injection moulded and tailored porosities were effectively achieved. After microstructural and mechanical characterisation, two different primary cells of mesenchymal origin (human umbilical cord perivascular cells and human bone derived cells which revealed to be two pertinent models) as well as one cell line originated from primary osteogenic sarcoma, Saos-2, were bestowed to investigate cell-material interaction on genomic and proteome levels. Biological examinations disclosed that no material has negative impact on early adhesion, proliferation or cell viability. An efficient cell ingrowth into material with an average porosity of 25-50 μm was proved.
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Affiliation(s)
- B J C Luthringer
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht (HZG), Geesthacht, Germany,
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82
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Palmquist A, Snis A, Emanuelsson L, Browne M, Thomsen P. Long-term biocompatibility and osseointegration of electron beam melted, free-form–fabricated solid and porous titanium alloy: Experimental studies in sheep. J Biomater Appl 2013. [DOI: 10.1177/0731684411431857] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The purpose of the present study was to evaluate the long-term osseointegration and biocompatibility of electron beam melted (EBM) free-form–fabricated (FFF titanium grade 5 (Ti6Al4V) implants. Porous and solid machined cylindrical and disk-shaped implants were prepared by EBM and implanted bilaterally in the femur and subcutaneously in the dorsum of the sheep. After 26 weeks, the implants and surrounding tissue were retrieved. The tissue response was examined qualitatively and quantitatively using histology and light microscopic (LM) morphometry. Selected bone implants specimens were evaluated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and micro-computed tomography (mCT). The results showed that both porous and solid implants were osseointegrated and high bone–implant contact was observed throughout the porous implant. In the soft tissue, the porous implants showed thinner fibrous encapsulation while no signs of intolerance were observed for either implant type. Taken together, the present experimental results show that FFF Ti6Al4V with and without porous structures demonstrate excellent long-term soft tissue biocompatibility and a high degree of osseointegration. The present findings extend earlier, short-term experimental observations in bone and suggest that EBM, FFF Ti6Al4V implants possess valuable properties in bone and soft tissue applications.
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Affiliation(s)
- A Palmquist
- Department of Biomaterials, Sahlgrenska Academy at University of Gothenburg Göteborg, Sweden
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy Göteborg, Sweden
| | - A Snis
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy Göteborg, Sweden
- Arcam AB Mölndal, Sweden
| | - L Emanuelsson
- Department of Biomaterials, Sahlgrenska Academy at University of Gothenburg Göteborg, Sweden
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy Göteborg, Sweden
| | - M Browne
- Bioengineering Group, School of Engineering Sciences, University of Southampton UK
| | - P Thomsen
- Department of Biomaterials, Sahlgrenska Academy at University of Gothenburg Göteborg, Sweden
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy Göteborg, Sweden
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83
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Wieding J, Souffrant R, Mittelmeier W, Bader R. Finite element analysis on the biomechanical stability of open porous titanium scaffolds for large segmental bone defects under physiological load conditions. Med Eng Phys 2013; 35:422-32. [DOI: 10.1016/j.medengphy.2012.06.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 04/25/2012] [Accepted: 06/15/2012] [Indexed: 10/28/2022]
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84
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Kim SE, Yun YP, Lee JY, Shim JS, Park K, Huh JB. Co-delivery of platelet-derived growth factor (PDGF-BB) and bone morphogenic protein (BMP-2) coated onto heparinized titanium for improving osteoblast function and osteointegration. J Tissue Eng Regen Med 2013; 9:E219-28. [PMID: 23288808 DOI: 10.1002/term.1668] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 08/23/2012] [Accepted: 11/05/2012] [Indexed: 11/10/2022]
Abstract
The aim of this study was to improve osteoblast function by delivering two growth factors, PDGF-BB and BMP-2, incorporated onto heparinized titanium (Hep-Ti) substrate. To achieve co-delivery of PDGF-BB and BMP-2, the surface of anodized Ti was immobilized with heparin, and then the two growth factors were coated onto the Hep-Ti surface. Incorporation of the two growth factors onto Hep-Ti was evaluated by SEM and XPS. Incorporated PDGF-BB and BMP-2 were released from the Hep-Ti substrate in a sustained manner. In vitro studies revealed that osteoblasts grown on PDGF-BB- and BMP-2-immobilized Hep-Ti increased ALP activity, calcium deposition, osteocalcin and osteopontin levels as compared to those grown on PDGF-BB alone- or BMP-2 alone-immobilized Hep-Ti. These results suggested that co-delivery of PDGF-BB and BMP-2 using Hep-Ti substrate will be a promising material for the enhancement of osteoblast function and osteointegration.
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Affiliation(s)
- Sung Eun Kim
- Department of Orthopaedic Surgery and Rare Diseases Institute, Korea University Medical Centre, Guro Hospital, 80 Guro-dong, Guro-gu, Seoul, 152-703, Korea
| | - Young-Pil Yun
- Department of Orthopaedic Surgery and Rare Diseases Institute, Korea University Medical Centre, Guro Hospital, 80 Guro-dong, Guro-gu, Seoul, 152-703, Korea
| | - Jae Yong Lee
- Department of Orthopaedic Surgery and Rare Diseases Institute, Korea University Medical Centre, Guro Hospital, 80 Guro-dong, Guro-gu, Seoul, 152-703, Korea
| | - June-Sung Shim
- Department of Prosthodontics, College of Dentistry, Younsei University, 134 Sinchon-dong, Seodaemun-gu, Seoul 120-749, Korea
| | - Kyeongsoon Park
- Division of Biological Imaging, Chuncheon Centre, Korea Basic Science Institute, 192-1 Hyoja 2-dong, Chuncheon, Gangwon-do, 200-701, Korea
| | - Jung-Bo Huh
- Department of Prosthodontics, College of Dentistry, Younsei University, 134 Sinchon-dong, Seodaemun-gu, Seoul 120-749, Korea.,Department of Prosthodontics, School of Dentistry, Pusan National University, Yang San, 626-787, Korea
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85
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Abdelaal OAM, Darwish SMH. Review of Rapid Prototyping Techniques for Tissue Engineering Scaffolds Fabrication. ADVANCED STRUCTURED MATERIALS 2013. [DOI: 10.1007/978-3-642-31470-4_3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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86
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Li X, Feng YF, Wang CT, Li GC, Lei W, Zhang ZY, Wang L. Evaluation of biological properties of electron beam melted Ti6Al4V implant with biomimetic coating in vitro and in vivo. PLoS One 2012; 7:e52049. [PMID: 23272208 PMCID: PMC3525565 DOI: 10.1371/journal.pone.0052049] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Accepted: 11/08/2012] [Indexed: 11/26/2022] Open
Abstract
Background High strength porous titanium implants are widely used for the reconstruction of craniofacial defects because of their similar mechanical properties to those of bone. The recent introduction of electron beam melting (EBM) technique allows a direct digitally enabled fabrication of patient specific porous titanium implants, whereas both their in vitro and in vivo biological performance need further investigation. Methods In the present study, we fabricated porous Ti6Al4V implants with controlled porous structure by EBM process, analyzed their mechanical properties, and conducted the surface modification with biomimetic approach. The bioactivities of EBM porous titanium in vitro and in vivo were evaluated between implants with and without biomimetic apatite coating. Results The physical property of the porous implants, containing the compressive strength being 163 - 286 MPa and the Young’s modulus being 14.5–38.5 GPa, is similar to cortical bone. The in vitro culture of osteoblasts on the porous Ti6Al4V implants has shown a favorable circumstance for cell attachment and proliferation as well as cell morphology and spreading, which were comparable with the implants coating with bone-like apatite. In vivo, histological analysis has obtained a rapid ingrowth of bone tissue from calvarial margins toward the center of bone defect in 12 weeks. We observed similar increasing rate of bone ingrowth and percentage of bone formation within coated and uncoated implants, all of which achieved a successful bridging of the defect in 12 weeks after the implantation. Conclusions This study demonstrated that the EBM porous Ti6Al4V implant not only reduced the stress-shielding but also exerted appropriate osteoconductive properties, as well as the apatite coated group. The results opened up the possibility of using purely porous titanium alloy scaffolds to reconstruct specific bone defects in the maxillofacial and orthopedic fields.
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Affiliation(s)
- Xiang Li
- School of Mechanical Engineering, Shanghai Jiao Tong University, State Key Laboratory of Mechanical System and Vibration, Shanghai, China
| | - Ya-Fei Feng
- Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi’an, China
| | - Cheng-Tao Wang
- School of Mechanical Engineering, Shanghai Jiao Tong University, State Key Laboratory of Mechanical System and Vibration, Shanghai, China
| | - Guo-Chen Li
- Department of Orthopaedics, Tangdu Hospital, The Fourth Military Medical University, Xi’an China
| | - Wei Lei
- Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi’an, China
| | - Zhi-Yong Zhang
- Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi’an, China
- Department of Plastic and Reconstructive Surgery, Shanghai 9th People’s Hospital, Shanghai Key Laboratory of Tissue Engineering, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- * E-mail: (LW); (ZYZ)
| | - Lin Wang
- Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi’an, China
- * E-mail: (LW); (ZYZ)
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87
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Bertollo N, Da Assuncao R, Hancock NJ, Lau A, Walsh WR. Influence of electron beam melting manufactured implants on ingrowth and shear strength in an ovine model. J Arthroplasty 2012; 27:1429-36. [PMID: 22503332 DOI: 10.1016/j.arth.2012.02.025] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Accepted: 02/27/2012] [Indexed: 02/01/2023] Open
Abstract
Arthroplasty has evolved with the application of electron beam melting (EBM) in the manufacture of porous mediums for uncemented fixation. Osseointegration of EBM and plasma-sprayed titanium (Ti PS) implant dowels in adult sheep was assessed in graduated cancellous defects and under line-to-line fit in cortical bone. Shear strength and bony ingrowth (EBM) and ongrowth (Ti PS) were assessed after 4 and 12 weeks. Shear strength of EBM exceeded that for Ti PS at 12 weeks (P = .030). Ongrowth achieved by Ti PS in graduated cancellous defects followed a distinctive pattern that correlated to progressively decreasing radial distances between defect and implant, whereas cancellous ingrowth values at 12 weeks for the EBM were not different. Osteoconductive porous structures manufactured using EBM present a viable alternative to traditional surface treatments.
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Affiliation(s)
- Nicky Bertollo
- Surgical and Orthopaedic Research Laboratories, University of New South Wales, Prince of Wales Clinical School, Sydney, Australia
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88
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Wieding J, Jonitz A, Bader R. The Effect of Structural Design on Mechanical Properties and Cellular Response of Additive Manufactured Titanium Scaffolds. MATERIALS 2012. [PMCID: PMC5448937 DOI: 10.3390/ma5081336] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Restoration of segmental defects in long bones remains a challenging task in orthopedic surgery. Although autologous bone is still the ‘Gold Standard’ because of its high biocompatibility, it has nevertheless been associated with several disadvantages. Consequently, artificial materials, such as calcium phosphate and titanium, have been considered for the treatment of bone defects. In the present study, the mechanical properties of three different scaffold designs were investigated. The scaffolds were made of titanium alloy (Ti6Al4V), fabricated by means of an additive manufacturing process with defined pore geometry and porosities of approximately 70%. Two scaffolds exhibited rectangular struts, orientated in the direction of loading. The struts for the third scaffold were orientated diagonal to the load direction, and featured a circular cross-section. Material properties were calculated from stress-strain relationships under axial compression testing. In vitro cell testing was undertaken with human osteoblasts on scaffolds fabricated using the same manufacturing process. Although the scaffolds exhibited different strut geometry, the mechanical properties of ultimate compressive strength were similar (145–164 MPa) and in the range of human cortical bone. Test results for elastic modulus revealed values between 3.7 and 6.7 GPa. In vitro testing demonstrated proliferation and spreading of bone cells on the scaffold surface.
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Affiliation(s)
- Jan Wieding
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +49-381-494-9338; Fax: +49-381-494-9308
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89
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Kim JE, Kang SS, Choi KH, Shim JS, Jeong CM, Shin SW, Huh JB. The effect of anodized implants coated with combined rhBMP-2 and recombinant human vascular endothelial growth factors on vertical bone regeneration in the marginal portion of the peri-implant. Oral Surg Oral Med Oral Pathol Oral Radiol 2012; 115:e24-31. [PMID: 23706924 DOI: 10.1016/j.oooo.2011.10.040] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 09/30/2011] [Accepted: 10/27/2011] [Indexed: 10/28/2022]
Abstract
OBJECTIVES The aim of this study was to evaluate the effect of anodized implants coated with combined rhBMP-2 and recombinant human vascular endothelial growth factors (rhVEGFs) on vertical bone regeneration in the marginal portion of the peri-implant. STUDY DESIGN Supra-alveolar defects were created in 3 male beagle dogs. Each animal received 8 implants that were either coated with a single growth factor (rhBMP-2) or combined growth factors (rhBMP-2 + rhVEGF), or an anodized implant (the control group). The amount of the vertical bone regeneration, the bone-implant contact, and the intrathread bone density were investigated using histomorphometric analysis at 8 weeks. RESULTS The bone morphogenetic protein (BMP) group and the BMP-VEGF group showed vertical alveolar bone regeneration and enhanced bone-implant contact in the microthread compared with the control group (P < .05). CONCLUSIONS Anodized implants coated with rhBMP-2 and rhBMP - 2 + rhVEGF can induce vertical alveolar bone regeneration, but the combined effect of rhBMP-2 and rhVEGF was not verified.
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Affiliation(s)
- Jong-Eun Kim
- Graduate Student, Advanced Prosthodontics, Postgraduate School of Clinical Dentistry, Institute for Clinical Dental Research, Korea University, Seoul, Korea
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90
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Unosson E, Persson C, Welch K, Engqvist H. Photocatalytic activity of low temperature oxidized Ti-6Al-4V. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2012; 23:1173-1180. [PMID: 22391995 DOI: 10.1007/s10856-012-4602-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 02/22/2012] [Indexed: 05/31/2023]
Abstract
Numerous advanced surface modification techniques exist to improve bone integration and antibacterial properties of titanium based implants and prostheses. A simple and straightforward method of obtaining uniform and controlled TiO(2) coatings of devices with complex shapes is H(2)O(2)-oxidation and hot water aging. Based on the photoactivated bactericidal properties of TiO(2), this study was aimed at optimizing the treatment to achieve high photocatalytic activity. Ti-6Al-4V samples were H(2)O(2)-oxidized and hot water aged for up to 24 and 72 h, respectively. Degradation measurements of rhodamine B during UV-A illumination of samples showed a near linear relationship between photocatalytic activity and total treatment time, and a nanoporous coating was observed by scanning electron microscopy. Grazing incidence X-ray diffraction showed a gradual decrease in crystallinity of the surface layer, suggesting that the increase in surface area rather than anatase formation was responsible for the increase in photocatalytic activity.
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Affiliation(s)
- Erik Unosson
- Division of Applied Materials Science, Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, Box 534, 751 21 Uppsala, Sweden.
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91
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Palmquist A, Snis A, Emanuelsson L, Browne M, Thomsen P. Long-term biocompatibility and osseointegration of electron beam melted, free-form-fabricated solid and porous titanium alloy: experimental studies in sheep. J Biomater Appl 2011; 27:1003-16. [PMID: 22207608 DOI: 10.1177/0885328211431857] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The purpose of the present study was to evaluate the long-term osseointegration and biocompatibility of electron beam melted (EBM) free-form-fabricated (FFF titanium grade 5 (Ti6Al4V) implants. Porous and solid machined cylindrical and disk-shaped implants were prepared by EBM and implanted bilaterally in the femur and subcutaneously in the dorsum of the sheep. After 26 weeks, the implants and surrounding tissue were retrieved. The tissue response was examined qualitatively and quantitatively using histology and light microscopic (LM) morphometry. Selected bone implants specimens were evaluated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and micro-computed tomography (mCT). The results showed that both porous and solid implants were osseointegrated and high bone-implant contact was observed throughout the porous implant. In the soft tissue, the porous implants showed thinner fibrous encapsulation while no signs of intolerance were observed for either implant type. Taken together, the present experimental results show that FFF Ti6Al4V with and without porous structures demonstrate excellent long-term soft tissue biocompatibility and a high degree of osseointegration. The present findings extend earlier, short-term experimental observations in bone and suggest that EBM, FFF Ti6Al4V implants possess valuable properties in bone and soft tissue applications.
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Affiliation(s)
- A Palmquist
- Department of Biomaterials, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden.
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92
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Abstract
OBJECTIVES Major changes are taking place in dental laboratories as a result of new digital technologies. Our aim is to provide an overview of these changes. In this article the reader will be introduced to the range of layered fabrication technologies and suggestions are made how these might be used in dentistry. METHODS Key publications in English from the past two decades are surveyed. RESULTS The first digital revolution took place many years ago now with the production of dental restorations such as veneers, inlays, crowns and bridges using dental CAD-CAM systems and new improved systems appear on the market with great rapidity. The reducing cost of processing power will ensure that these developments will continue as exemplified by the recent introduction of a new range of digital intra-oral scanners. With regard to the manufacture of prostheses this is currently dominated by subtractive machining technology but it is inevitable that the additive processing routes of layered fabrication, such as FDM, SLA, SLM and inkjet printing, will start to have an impact. In principle there is no reason why the technology cannot be extended to all aspects of production of dental prostheses and include customized implants, full denture construction and orthodontic appliances. In fact anything that you might expect a dental laboratory to produce can be done digitally and potentially more consistently, quicker and at a reduced cost. SIGNIFICANCE Dental device manufacturing will experience a second revolution when layered fabrication techniques reach the point of being able to produce high quality dental prostheses. The challenge for the dental materials research community is to marry the technology with materials that are suitable for use in dentistry. This can potentially take dental materials research in a totally different direction.
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93
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Ramazanoglu M, Lutz R, Ergun C, von Wilmowsky C, Nkenke E, Schlegel KA. The effect of combined delivery of recombinant human bone morphogenetic protein-2 and recombinant human vascular endothelial growth factor 165 from biomimetic calcium-phosphate-coated implants on osseointegration. Clin Oral Implants Res 2011; 22:1433-9. [PMID: 21418332 DOI: 10.1111/j.1600-0501.2010.02133.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVES The delivery of growth factors for enhanced osseointegration depends on the effectiveness of the carrier systems at the bone-implant interface. This study evaluated the effect of solo and dual delivery of recombinant human bone morphogenetic protein-2 (rhBMP-2) and recombinant human vascular endothelial growth factor (rhVEGF(165) ) from biomimetically octacalcium phosphate-coated implants on osseointegration. MATERIALS AND METHODS Biomimetic implants, bearing either a single growth factor (BMP or VEGF) or their combination (BMP+VEGF), were established, and compared with acid-etched (AE, control) and biomimetic implants without growth factor (CAP). Implants were placed into frontal skulls of nine domestic pigs. The quality of osseointegration was evaluated using microradiographic and histomorphometric analysis of bone formation inside four defined bone chambers of the experimental implant at 1, 2 and 4 weeks. RESULTS Biomimetic implants, either with or without growth factor, showed enhanced bone volume density (BVD) values after 2 and 4 weeks. This enhancement was significant for the BMP and BMP+VEGF group compared with the control AE group after 2 weeks (P<0.05). All biomimetic calcium-phosphate (Ca-P) coatings exhibited significantly enhanced bone-implant contact (BIC) rates compared with the uncoated control surface after 2 weeks (P<0.05). However, the combined delivery of BMP-2 and VEGF did not significantly enhance BIC at the final observation period. CONCLUSION It was concluded that the combined delivery of BMP-2 and VEGF enhances BVD around implants, but not BIC. Therefore, it may be assumed that changes in the surface characteristics should be considered when designing growth factor-delivering surfaces.
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Affiliation(s)
- Mustafa Ramazanoglu
- Department of Oral Surgery, Faculty of Dentistry, Istanbul University, Istanbul, Turkey.
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94
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Abstract
Bone tissue engineering is an emerging interdisciplinary field in Science, combining expertise in medicine, material science and biomechanics. Hard tissue engineering research is focused mainly in two areas, osteo and dental clinical applications. There is a lot of exciting research being performed worldwide in developing novel scaffolds for tissue engineering. Although, nowadays the majority of the research effort is in the development of scaffolds for non-load bearing applications, primarily using soft natural or synthetic polymers or natural scaffolds for soft tissue engineering; metallic scaffolds aimed for hard tissue engineering have been also the subject of in vitro and in vivo research and industrial development. In this article, descriptions of the different manufacturing technologies available to fabricate metallic scaffolds and a compilation of the reported biocompatibility of the currently developed metallic scaffolds have been performed. Finally, we highlight the positive aspects and the remaining problems that will drive future research in metallic constructs aimed for the reconstruction and repair of bone.
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Affiliation(s)
- Kelly Alvarez
- Center for Geo-Environmental Science, Faculty of Engineering and Resource Science, Akita University, 1-1 Tegata Gakuen-machi, Akita 010-8502, Japan; E-Mail:
| | - Hideo Nakajima
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
- Author to whom correspondence should be addressed; E-Mail: ; Tel. +81-6-6879-8435; Fax: +81-6-6879-8439
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