title: High resolution electron microscopic observation of hydroxyapatite in tooth crystals.
abstract: Structure images taken with a high resolution electron microscope with a resolution of 0.18 nm revealed that the atomic arrangement in tooth-enamel hydroxyapatite (HA) corresponds with the calculated image using crystallographic data from mineral HA (Ca10(PO4)6(OH)2). Direct information on the two types of Ca and the OH- groups in the HA crystals was obtained from the observed image through [001] projection. The established correspondence between the observed image contrast and the arrangements of the columnar Ca, the screw-axis Ca, and the OH- groups suggests that HREM observations are useful to identify defects in HA crystals.
authors.affiliation: Department of Chemistry and Material Science, Kyoto University of Education, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Shibahara
authors.forename: H
authors.initials: H
authors.lastname: Tohda
authors.forename: T
authors.initials: T
authors.lastname: Yanagizawa
mesh_terms: D018360:Crystallography, X-Ray; D003743:Dental Enamel / Q000648:ultrastructure*; D017886:Durapatite / Q000737:chemistry*; D006801:Humans; D008854:Microscopy, Electron; D015394:Molecular Structure
chemical_list: D017886:Durapatite