Biomaterials

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Biomaterials 28 (2007) 2908–2914 www.elsevier.com/locate/biomaterials

2D mapping of texture and lattice parameters of dental enamel
Maisoon Al-Jawada,Ã, Axel Steuwerb, Susan H. Kilcoynec, Roger C. Shorea, Robert Cywinskid, David J. Wooda a Leeds Dental Institute, University of Leeds, Leeds, LS2 9LU, UK FaME38 at the ILL-ESRF, 6 rue J Horowitz, 38042 Grenoble, France c Institute for Materials Research, University of Salford, Salford, M5 4WT, UK d School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK b

Received 19 December 2006; accepted 16 February 2007 Available online 25 February 2007

Abstract We have used synchrotron X-ray diffraction to study the texture and the change in lattice parameter as a function of position in a cross section of human dental enamel. Our study is the first to map changes in preferred orientation and lattice parameter as a function of position within enamel across a whole tooth section with such high resolution. Synchrotron X-ray diffraction with a micro-focused beam spot was used to collect two-dimensional (2D) diffraction images at 150 mm spatial resolution over the entire tooth crown. Contour maps of the texture and lattice parameter distribution of the hydroxyapatite phase were produced from Rietveld refinement of diffraction patterns generated by azimuthally sectioning and integrating the 2D images. The 002 Debye ring showed the largest variation in intensity. This variation is indicative of preferred orientation. Areas of high crystallite alignment on the tooth cusps match the expected biting surfaces. Additionally we found a large variation in lattice parameter when travelling from the enamel surface to the enameldentine junction. We believe this to be due to a change in the chemical composition within the tooth. The results provide a new insight on the texture and lattice parameter…...

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