title: Evaluation of enamel crystallites in subsurface lesion by microbeam X-ray diffraction.
abstract: Early caries lesion is a demineralization process that takes place in the top 0.1 mm layer of tooth enamel. In this study, X-ray microbeam diffraction was used to evaluate the hydroxyapatite crystallites in the subsurface lesion of a bovine enamel section and the results are compared with those obtained by transversal microradiography, a method commonly used for evaluation of tooth mineral. Synchrotron radiation from SPring-8 was used to obtain a microbeam with a diameter of 6 microm. Wide-angle X-ray diffraction reports the amount of hydroxyapatite crystals, and small-angle X-ray scattering reports that of voids in crystallites. All three methods showed a marked decrease in the enamel density in the subsurface region after demineralization. As these diffraction methods provide structural information in the nanometre range, they are useful for investigating the mechanism of the mineral loss in early caries lesion at a nanometre level.
authors.affiliation: Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan. yagi@spring8.or.jp
authors.forename: N
authors.initials: N
authors.lastname: Yagi
authors.forename: N
authors.initials: N
authors.lastname: Ohta
authors.forename: T
authors.initials: T
authors.lastname: Matsuo
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: Y
authors.initials: Y
authors.lastname: Terada
authors.forename: H
authors.initials: H
authors.lastname: Kamasaka
authors.forename: K
authors.initials: K
authors.lastname: To-o
authors.forename: T
authors.initials: T
authors.lastname: Kometani
authors.forename: T
authors.initials: T
authors.lastname: Kuriki
mesh_terms: D000818:Animals; D002417:Cattle; D003743:Dental Enamel / Q000000981:diagnostic imaging* / Q000648:ultrastructure*; D066298:In Vitro Techniques; D011859:Radiography; D013499:Surface Properties; D014961:X-Ray Diffraction / Q000379:methods*