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Graded Microstructure and Mechanical Properties of Human Crown Dentin



W Tesch, Naomi Eidelman, P Roschger, F Goldenberg, K Klaushofer, P Fratzl


The mineralized tissue of intertubular dentin is a collagen-mineral composite with considerable local variations of mechanical properties. Area-scans of human tooth were made by complementary methods to investigate correlations between local mechanical properties and the density, size and crystallinity of the mineral particles. Scanning-images from the same specimen were collected with Fourier-transform infrared microspectroscopy in reflectance mode (FTIR-RM), small angle X-ray scattering (SAXS), quantitative backscattered electron imaging (qBEI) and nanoindentation in an atomic force microscope. The mineral content of dentin was found to decrease and the thickness of mineral crystals to increase towards the dentin-enamel-junction (DEJ). Hardness and elastic modulus both decreased towards the DEJ. In a correlation analysis, the mineral content and, even more, the thickness of mineral crystals were found as the best predictors of hardness. The dentin layer close to the DEJ corresponds to a local minimum in hardness and elastic modulus, a configuration known to be an effective obstacle for crack propagation. Hence, the observed variations of mechanical and structural properties close to the DEJ define crown dentin as a gradient material optimized for its mechanical function.
Calcified Tissue International
No. 3


dentin, fourier transform infrared microspectros, nanoindentation, quantitative backscattered electron imag, small-angle x-ray


Tesch, W. , Eidelman, N. , Roschger, P. , Goldenberg, F. , Klaushofer, K. and Fratzl, P. (2001), Graded Microstructure and Mechanical Properties of Human Crown Dentin, Calcified Tissue International (Accessed April 18, 2024)
Created August 31, 2001, Updated October 12, 2021