OBJECTIVETo investigate the crystallographic properties of the mineral phases of normal enamel and dentin (dental apatite) in deciduous and permanent teeth.

METHODSThree kinds of physical methods including X-ray diffraction (XRD), infrared absorption spectroscope (IR) and electron probe micro-analysis (EPMA) were utilized in this study.

RESULTSDental apatite was not uniphase, but multiphase, which could be described as carbonate-substituted hydroxyapatite. Compared to dentin apatite, the higher crystallinity and expanded a-axis lattice parameters were found in enamel. Chemical analyses demonstrated that higher concentrations of Mg and CO(3)(2-) were found in dentin than those of enamel. But enamel had higher Cl content.

CONCLUSIONSThe differences among enamel and dentin, in terms of lattice parameter and crystallinity may be partially attributed to the incorporation of Mg, CO(3)(2-) and Cl minor elements.

Dental Enamel ; chemistry ; Dentin ; chemistry ; Electron Probe Microanalysis ; methods ; Humans ; Spectrophotometry, Infrared ; methods ; Tooth ; chemistry ; X-Ray Diffraction ; methods