Orientations of Carbonate Ions in Human Tooth Enamel Studied with Use of the CO 3-3 Radical Ions as Probes

Abstract
With the use of CO 3-3 radical ions as probes, it is concluded that the carbonate ions substitute in the apatite lattice of human tooth enamel in two different ways. Most of the carbonate ions in the apatite lattice are aligned with their symmetry axis parallel to the c axis, whereas the remaining carbonate ions are aligned with their symmetry axis perpendicular to the c axis.