TY - CONF A1 - Bauer, L. J. T1 - Integrated X-ray techniques for durable dental interzones N2 - Nowadays, teeth are not directly extracted when tooth decay occurs. Whenever treatment of the affected tooth is possible, the carious region is replaced with a suitable filling. The filling material differs according to the position and size of the cavity. Since the restoration will remain in the tooth for many years, a well adhering and sealing interface between filling and healthy tooth tissue is needed. There is continuous development of new materials, but intensive studies of this complex interface between filling and healthy tooth are still lacking. Little is known about possible diffusion of elements from dental materials into healthy tooth tissue forming a socalled interzone with specific chemical and structural properties. The combination of different analytical X-ray methods at synchrotron radiation facilities and in the laboratory enables an extensive structural and elemental investigation of such interzones. While X-ray fluorescence techniques and X-ray absorption spectroscopy yield elemental distributions and localized chemical speciation, X-ray diffraction, refraction and computed tomography add structural information to the full 3D analysis of model and real life tooth samples. Within two DFG funded projects, we develop adapted methodologies and investigate micro-chemical changes in interzones which we hypothesize may lead to sclerotic dentine. T2 - Workshop of the Helmholtz association: MML - "From Matter to Materials and Life" CY - Berlin, Germany DA - 22.11.2021 KW - Dental materials KW - X-ray refraction KW - Computed tomography KW - X-ray fluorescence PY - 2021 AN - OPUS4-54097 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bauer, L.J. A1 - Wieder, Frank A1 - Truong, V. A1 - Förste, F. A1 - Wagener, Y. A1 - Jonas, A. A1 - Praetz, S: A1 - Schlesiger, C. A1 - Kupsch, Andreas A1 - Müller, Bernd R. A1 - Kanngießer, B. A1 - Zaslansky, P. A1 - Mantouvalou, I. T1 - Absorption Correction for 3D Elemental Distributions of Dental Composite Materials Using Laboratory Confocal Micro-X-ray Fluorescence Spectroscopy N2 - Confocal micro-X-ray fluorescence (micro-XRF) spectroscopy facilitates three-dimensional (3D) elemental imaging of heterogeneous samples in the micrometer range. Laboratory setups using X-ray tube excitation render the method accessible for diverse research fields but interpretation of results and quantification remain challenging. The attenuation of X-rays in composites depends on the photon energy as well as on the composition and density of the material. For confocal micro-XRF, attenuation severely impacts elemental distribution information, as the signal from deeper layers is distorted by superficial layers. Absorption correction and quantification of fluorescence measurements in heterogeneous composite samples have so far not been reported. Here, an absorption correction approach for confocal micro-XRF combining density information from microcomputed tomography (micro-CT) data with laboratory X-ray absorption spectroscopy (XAS) and synchrotron transmission measurements is presented. The energy dependency of the probing volume is considered during the correction. The methodology is demonstrated on a model composite sample consisting of a bovine tooth with a clinically used restoration material. KW - Micro X-ray fluorescence spectroscopy KW - Dental composite materials KW - Computed tomography KW - Absorption correction PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601630 DO - https://doi.org/10.1021/acs.analchem.4c00116 SN - 0003-2700 SN - 1520-6882 VL - 96 IS - 21 SP - 8441 EP - 8449 PB - American Chemical Society Publications CY - Washington, DC AN - OPUS4-60163 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mantouvalou, I. A1 - Bauer, L.J. A1 - Truong, V.-B. A1 - Wagener, Y. A1 - Förste, F. A1 - Maruchenko, O. A1 - Werner, S. A1 - Lizzi, F. A1 - Wieder, Frank A1 - Wolff, T. A1 - Kanngießer, B. A1 - Zaslansky, P. T1 - Quantitative micro-XRF combined with X-ray imaging reveals correlations between Zn concentration and dentin tubule porosity across entire teeth N2 - Bony materials are biogenic composites of protein fibers and mineral that create hierarchical structures. In the case of teeth, dentin is the main component and similar to other bones, it contains porosity at multiple length scales. It is traversed by micron-sized hollow channels known as dentinal tubules, essential for temperature and pain sensation. Tubule density and thus porosity vary throughout the macroscopic three-dimensional (3D) structure, with porosity increasing toward the pulp. The different densities in teeth are easily revealed non-destructively in 3D by X-ray imaging using computer tomography (CT). Yet elemental composition analysis is more difficult to obtain from within the centimeter-sized heterogeneous bulk material. We describe an approach of merging CT measurements of healthy, intact bovine teeth with micro-X-ray fluorescence (micro-XRF) images of matching serially sectioned slices. Through the combination of multi-resolution quantitative CT measurements with elemental mass fraction derivation, gradients in density and element distributions such as calcium (Ca), phosphorus (P), and zinc (Zn) are revealed across entire teeth in 3D. While the main constituents (Ca and P) are homogeneously distributed in the matrix, Zn concentration increases significantly and exponentially toward the pulp. We find an inverse association between dentin tissue density and Zn concentration localizing this element in or around tubules. Our data serve as a quantitative reference for density and Zn mass fractions in healthy, neither carious nor hypermineralized dentin, as a basis for comparisons across species in health and disease states. KW - Dentin density KW - Micro-computer tomography KW - Quantitative micro-X-ray fluorescence KW - Tubule porosity KW - Zn distribution PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654215 DO - https://doi.org/10.1002/VIW.20250173 SN - 2688-3988 SN - 2688-268X SP - 1 EP - 14 PB - Wiley Online Library AN - OPUS4-65421 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -