TY - JOUR A1 - Rack, A. A1 - Weitkamp, T. A1 - Zanette, I. A1 - Morawe, C. A1 - Vivo Rommeveaux, A. A1 - Tafforeau, P. A1 - Cloetens, P. A1 - Ziegler, E. A1 - Rack, T. A1 - Cecilia, A. A1 - Vagovic, P. A1 - Harmann, E. A1 - Dietsch, R. A1 - Riesemeier, Heinrich T1 - Coherence preservation and beam flatness of a single-bounce multilayer monochromator (beamline ID19-ESRF) JF - Nuclear instruments and methods in physics research A N2 - Larger spectral bandwidth and higher photon flux density are the major advantages of multilayer monochromators over crystal-based devices. Especially for synchrotron-based hard X-ray microimaging applications the increased photon flux density is important in order to achieve high contrast and resolution in space and/or time. However, the modifications on the beam profile induced by reflection on a multilayer are a drawback which can seriously harm the performance of such a monochromator. A recent study [A. Rack, T. Weitkamp, M. Riotte, D. Grigoriev, T. Rack, L. Helfen, T. Baumbach, R. Dietsch, T. Holz, M. Krämer, F. Siewert, M. Meduna, P. Cloetens, E. Ziegler, J. Synchrotron Radiat. 17 (2010) 496–510] has shown that the modifications in terms of beam flatness and coherence preservation can be influenced via the material composition of the multilayer coating. The present article extends this knowledge by studying further material compositions used on a daily basis for hard X-ray monochromatization at the beamline ID19 of the European Synchrotron Radiation Facility. KW - Multilayer mirrors KW - X-rays KW - X-ray optics KW - Coherence KW - X-ray monochromators KW - X-ray imaging KW - X-ray phase contrast KW - Synchrotron radiation PY - 2011 DO - https://doi.org/10.1016/j.nima.2010.11.069 SN - 0168-9002 SN - 0167-5087 VL - 649 IS - 1 SP - 123 EP - 127 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-25240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rack, T. A1 - Zabler, S. A1 - Rack, C. A1 - Stiller, M. A1 - Riesemeier, Heinrich A1 - Cecilia, A. A1 - Nelson, K. T1 - Coherent synchrotron-based micro-imaging employed for studies of micro-gap formation in dental implants T2 - 10th International conference on X-ray microscopy (AIP conference proceedings) N2 - Biocompatible materials such as titanium are regularly applied in oral surgery. Titanium-based implants for the replacement of missing teeth demand a high mechanical precision in order to minimize micro-bacterial leakage, especially when two-piece concepts are used. Synchrotron-based hard x-ray radiography, unlike conventional laboratory radiography, allows high spatial resolution in combination with high contrast even when micro-sized features in such highly attenuating objects are visualized. Therefore, micro-gap formation at interfaces in two-piece dental implants with the sample under different mechanical loads can be studied. We show the existence of micro-gaps in implants with conical connections and study the mechanical behavior of the mating zone of conical implants during loading. The micro-gap is a potential source of implant failure, i.e., bacterial leakage, which can be a stimulus for an inflammatory process. T2 - 10th International conference on X-ray microscopy CY - Chicago, Illinois, USA DA - 15.08.2010 KW - X-ray imaging KW - Dental implants KW - Digital radiography KW - Implant-abutment interface KW - Synchrotron radiation KW - X-ray phase contrast PY - 2011 SN - 978-0-7354-0925-5 DO - https://doi.org/10.1063/1.3625398 N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 1365 SP - 445 EP - 448 AN - OPUS4-25347 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rack, A. A1 - Rack, T. A1 - Stiller, M. A1 - Riesemeier, Heinrich A1 - Zabler, S. A1 - Nelson, K. T1 - In vitro synchrotron-based radiography of micro-gap formation at the implant-abutment interface of two-piece dental implants JF - Journal of synchrotron radiation N2 - Micro-gap formation at the implant-abutment interface of two-piece dental implants was investigated in vitro using high-resolution radiography in combination with hard X-ray synchrotron radiation. Images were taken with the specimen under different mechanical loads of up to 100 N. The aim of this investigation was to prove the existence of micro-gaps for implants with conical connections as well as to study the mechanical behavior of the mating zone of conical implants during loading. Synchrotron-based radiography in comparison with classical laboratory radiography yields high spatial resolution in combination with high contrast even when exploiting micro-sized features in highly attenuating objects. The first illustration of a micro-gap which was previously indistinguishable by laboratory methods underlines that the complex micro-mechanical behavior of implants requires further in vitro investigations where synchrotron-based micro-imaging is one of the prerequisites. KW - X-ray imaging KW - Dental implants KW - Digital radiography KW - Implant-abutment interface PY - 2010 DO - https://doi.org/10.1107/S0909049510001834 SN - 0909-0495 SN - 1600-5775 VL - 17 IS - 2 SP - 289 EP - 294 PB - Blackwell Publishing CY - Oxford AN - OPUS4-22121 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -