ABSTRACT
Dental enamel is the most highly mineralized of the mammalian skeletal tissues. The distribution of mineral, water, and organic material within the tissue is, in addition, not uniform but is related to the microanatomy and ultrastructure of the tissue. Organic material appears to be located more specifically toward the periphery of the prisms. This visible evidence of histological heterogeneity is reflected in differences in the mineral content from site to site. Point defects can arise from a vacancy, an extra or interstitial ion, or substitution of an apatitic ion by an extraneous ion. In enamel these are most likely to give rise to calcium deficiencies and result in lower than theoretical calcium to phosphorus ratios. In addition, the calcium phosphate system itself is complex and a wide variety of species may be present, which may include minor inorganic components.
