Moin D.A.,Academic Center for Dentistry Amsterdam |
Hassan B.,Academic Center for Dentistry Amsterdam |
Mercelis P.,LayerWise NV |
Wismeijer D.,Academic Center for Dentistry Amsterdam
Clinical Oral Implants Research | Year: 2013
Objectives: The study aim is to introduce a novel preemptively constructed dental root analogue implant (RAI) based on three-dimensional (3D) root surface models obtained from a cone beam computed tomography (CBCT) scan, computer aided designing and computer aided manufacturing technology. Materials & Methods: One partially edentulous mandibular human cadaver was scanned with the Accuitomo 170 CBCT system. The scan volumes and datasets were used to create 3D surface models of the tooth. A 3D surface mesh of the tooth was stored as a standard triangulation language (STL) file. A high-end selective laser melting technology was used to fabricate the RAI from the STL file. The RAI was produced in a biocompatible titanium alloy (Ti6Al4V). Optical scanning technology was used to measure the RAI, as well as the natural tooth that was extracted. To validate the accuracy of the CBCT 3D root surface and the manufactured Titanium RAI, both surfaces were superimposed on the optical scan of the tooth, which served as the gold "reference" standard. Results: The differences between the RAI and the optical scan of the original tooth are most noticeable at the level of the apex and the cementenamel junction areas on the buccal and lingual side (divergence of more than 0.15 mm). Surface area measurements show an overall decrease in surface area of 6.33% for the RAI in comparison with the original tooth and an increase of 0.27% when comparing the 3D surface model with optical scan of the original tooth. Conclusion: With the use of currently available technology it is very well feasible to preemptively create a custom RAI in titanium. However, clinical evidence evaluating the success of this novel dental implant approach is needed. © 2011 John Wiley & Sons A/S.
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: FoF.NMP.2012-5 | Award Amount: 5.19M | Year: 2012
The Hi-Micro project intends to realise an innovative approach for the design, manufacturing and quality control of tool inserts to achieve significant breakthrough in mass production of precision 3D micro-parts, through further developing both enabling manufacturing technologies, including additive manufacturing (AM), micro electrical discharge machining (micro-EDM), micro electro-chemical machining (micro-ECM) and micro-milling, and unique metrology and quality control methods such as computer-tomography (CT) metrology and digital holography. Together with industrial technology providers, the Hi-Micro project will further bolster the performance of industrial equipment for mass production of precision 3D micro-parts, through modular design of tool insert units with improved thermal management capability, development of on-machine handling system and in-line quality control device. Activities will run over the entire value chain of mass production of precision 3D micro-parts, from product and tool insert design, manufacturing of tool inserts, micro injection moulding processes, to the production equipment and quality control in the whole production chain. In order to tackle the identified challenges and critical problems, the Hi-Micro project will provide radical innovations and major breakthroughs as follows: Development of design and tolerance guidelines for advanced micro manufacturing of components (nominal size <1mm) Reliable capability of manufacturing tool inserts with complex internal features for conformal thermal management in micro-injection moulding (IM) and micro powder injection moulding (PIM) Processing technologies and equipment for manufacturing of 3D micro-parts with increased precision and accuracy to ensure smaller tolerances for the products, Metrology methods for complex internal structure and high-speed inline quality control with improved measurement efficiency and without loss of resolution or accuracy.
Agency: European Commission | Branch: FP7 | Program: BSG-SME | Phase: SME-2011-1 | Award Amount: 1.50M | Year: 2012
ImplantDirect will create a cost-effective, faster manufacturing route for orthopaedic, maxillofacial or trauma implants, tailored to the individual needs of patients. The overall project aims are to improve the quality of the implants, reduce the recovery time, improve the quality of life for the patients and reduce the healthcare costs. This will be achieved by allowing surgeons to personalise the implants to fit the patient and the individual trauma, thus reducing the need for revisions, the length of surgery time and the recovery time of the patient. While the technology is available and can deliver the well-recognised benefits of using personalised implants, the number of clinical cases is still limited. The main reasons that the technology has not been widely applied for treatment in hospitals, are the complexity of the delivery process, the high cost of implants and the lack of human and technological resources in the area of biomodelling in hospitals. Especially, the multidisciplinary communication among radiologists, surgeons, and biomedical engineers, which is always needed during the design and manufacturing steps of a patient specific implant. In addition, the optimal solutions and funding for investment of hardware and software are not always available. The work to be undertaken in ImplantDirect will help overcome these issues by the realisation of two key innovations: 1) An innovative software solution that will allow the surgeon to directly design the best (not limited by existing manufacturing techniques) implant shape for his patients, based on CT-scan data, which will then allow implant creation using the flexible Rapid Manufacturing technique of Selective Laser Melting. 2) Develop the Selective Laser Melting process and post-processing necessary to deliver functional Ti6Al4V personalised implants within 3 days from receiving the designs from innovation 1.
Agency: European Commission | Branch: FP7 | Program: CSA-SA | Phase: NMP.2012.4.0-2 | Award Amount: 682.65K | Year: 2012
SASAMs mission is to drive the growth of AM to efficient and sustainable industrial processes by integrating and coordinating Standardisation activities for Europe by creating and supporting a Standardisation organisation in the field of AM. The Additive Manufacturing (AM) concept is based on additive freeform fabrication technologies for the automated production of complex products. Additive Manufacturing is defined as the direct production of finished goods using additive processes from digital data. A key advantage is that AM eliminates the need for tooling, such as moulds and dies, that can make the introduction of new products prohibitively expensive, both in time and money. This enables the production of forms that have been long considered impossible by conventional series productionin fact, they can be created fast, flexibly, and with fewer machines.
Deprez K.,Ghent University |
Vandenberghe S.,Ghent University |
Van Audenhaege K.,Ghent University |
Van Vaerenbergh J.,Layerwise NV |
Van Holen R.,Ghent University
Medical Physics | Year: 2013
Purpose: The construction of complex collimators with a high number of oblique pinholes is very labor intensive, expensive or is sometimes impossible with the current available techniques (drilling, milling or electric discharge machining). All these techniques are subtractive: one starts from solid plates and the material at the position of the pinholes is removed. The authors used a novel technique for collimator construction, called metal additive manufacturing. This process starts with a solid piece of tungsten on which a first layer of tungsten powder is melted. Each subsequent layer is then melted on the previous layer. This melting is done by selective laser melting at the locations where the CAD design file defines solid material. Methods: A complex collimator with 20 loftholes with 500 μm diameter pinhole opening was designed and produced (16 mm thick and 70 × 52 mm2 transverse size). The density was determined, the production accuracy was measured (GOM ATOS II Triple Scan, Nikon AZ100M microscope, Olympus IMT200 microscope). Point source measurements were done by mounting the collimator on a SPECT detector. Because there is increasing interest in dual-modality SPECT-MR imaging, the collimator was also positioned in a 7T MRI scanner (Bruker Pharmascan). A uniform phantom was acquired using T1, T2, and T2* sequences to check for artifacts or distortion of the phantom images due to the collimator presence. Additionally, three tungsten sample pieces (250, 500, and 750 μm thick) were produced. The density, attenuation (140 keV beam), and uniformity (GE eXplore Locus SP micro-CT) of these samples were measured. Results: The density of the collimator was equal to 17.31 ± 0.10 g/cm3 (89.92% of pure tungsten). The production accuracy ranges from -260 to +650 μm. The aperture positions have a mean deviation of 5 μm, the maximum deviation was 174 μm and the minimum deviation was -122 μm. The mean aperture diameter is 464 ± 19 μm. The calculated and measured sensitivity and resolution of point sources at different positions in the field-of-view agree well. The measured and expected attenuation of the three sample pieces are in a good agreement. There was no influence of the 7T magnetic field on the collimator (which is paramagnetic) and minimal distortion was noticed on the MR scan of the uniform phantom. Conclusions: Additive manufacturing is a very promising technique for the production of complex multipinhole collimators and may also be used for producing other complex collimators. The cost of this technique is only related to the amount of powder needed and the time it takes to have the collimator built. The timeframe from design to collimator production is significantly reduced. © 2013 American Association of Physicists in Medicine.
Thijs L.,Catholic University of Leuven |
Montero Sistiaga M.L.,Catholic University of Leuven |
Wauthle R.,Catholic University of Leuven |
Wauthle R.,LayerWise NV |
And 3 more authors.
Acta Materialia | Year: 2013
Selective laser melting (SLM) makes use of a high energy density laser beam to melt successive layers of metallic powders in order to create functional parts. The energy density of the laser is high enough to melt refractory metals like Ta and produce mechanically sound parts. Furthermore, the localized heat input causes a strong directional cooling and solidification. Epitaxial growth due to partial remelting of the previous layer, competitive growth mechanism and a specific global direction of heat flow during SLM of Ta result in the formation of long columnar grains with a âŒ©1 1 1âŒ preferential crystal orientation along the building direction. The microstructure was visualized using both optical and scanning electron microscopy equipped with electron backscattered diffraction and the global crystallographic texture was measured using X-ray diffraction. The thermal profile around the melt pool was modeled using a pragmatic model for SLM. Furthermore, rotation of the scanning direction between different layers was seen to promote the competitive growth. As a result, the texture strength increased to as large as 4.7 for rotating the scanning direction 90 every layer. By comparison of the yield strength measured by compression tests in different orientations and the averaged Taylor factor calculated using the viscoplastic self-consistent model, it was found that both the morphological and crystallographic texture observed in SLM Ta contribute to yield strength anisotropy. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
LayerWise N.V. | Date: 2016-10-19
The invention concerns an implant for adjusting the position of at least one tissue holder (6) for soft tissue, whereby this implant can be fixed to bone tissue at a distance from said tissue holder (6) and has a guide (3) for an elongate pulling member (4), whereby this pulling member (4) is connected to said tissue holder (6), and whereby the implant includes a fixing element (10) which can be moved between a fixing position in which the pulling member (4) is clamped by the fixing element (10) and a free position in which said pulling member (4) can freely move through said guide (3), wherein said fixing element (10) cooperates with a control element (14) which makes it possible to move this fixing element (10) between said fixing position and said free position when the implant is attached to said bone tissue and when the implant is covered with soft tissue such as muscle tissue or skin tissue. Said fixing element (10) is made of a memory metal or a bimetal and said control element is formed of a cold or heat source.
Layerwise N.V. | Date: 2012-02-06
The invention concerns a method for manufacturing at least one thin-walled structure (1,11,13,17,18), whereby this structure is built layer by layer by applying successive powder layers extending substantially horizontally and by moving an energy beam over each of these powder layers according to a predetermined pattern so as to make said powder melt and subsequently make it solidify or sinter, such that successive layers connected to each other of said thin-walled structure (1,11, 13,17,18) are formed which extend according to a horizontal cross section of this thin-walled structure (1, 11,13,17,18). According to the method a support structure (20) is built in layers together with said thin-walled structures (1,11,13,17,18) and connected to it such that a rigid unit (14) is manufactured, whereby after building this unit (14) layer by layer, at least the thin-walled structures (1,11,13,17,18) are annealed in order to at least partly eliminate any stresses present, and whereby both structures are separated from each other.
Layerwise N.V. | Date: 2013-02-15
The invention concerns an implant for adjusting the position of at least one tissue holder (6) for soft tissue, whereby this implant can be fixed to bone tissue at a distance from said tissue holder (6) and has a guide (3) for an elongate pulling member (4), whereby this pulling member (4) is connected to said tissue holder (6), and whereby the implant includes a fixing element (10) which can be moved between a fixing position in which the pulling member (4) is clamped by the fixing element (10) and a free position in which said pulling member (4) can freely move through said guide (3), characterised in that said fixing element (10) cooperates with a control element (14) which makes it possible to move this fixing element (10) between said fixing position and said free position when the implant is attached to said bone tissue and when the implant is covered with soft tissue such as muscle tissue or skin tissue.
Layerwise N.V. | Date: 2014-12-03
The invention concerns a method and a device for calibrating at least one scanning system (4, 5, 17) when producing an object (8) by additive manufacturing, wherein the coordinates of one or several reference positions are measured in the relative coordinate system of each scanning system (4, 5, 17), after which the calibration of each of the scanning systems is adapted starting from the measured coordinates of the reference positions.