Gradients in the composition of enamel and dentin mineral in rat incisors

Abstract

In order to investigate possible diffrences in the mineral composition of rat incisors, Wistar rats received either a zinc-deficient or a normal diet (the latter were pair fed or ad libitum). Three incisors from each group were subjected to microanalysis by me electron microprobe. No differences were found in mineraI composition between the three groups. The average molar Ca/P ratio in the enamel and the dentin were (1.62+/- 0.05) and ( 1.50 +/- 0.05), respectively. The distribution of sodium and magnesium over the dentin was homogeneous and inhomogeneous , respectively. Dentin did not contain detectable amounts of chlorine. The gradients for sodium, magnesium and chlorine as a function of depth in enamel were similar to those reported for these elements in human and rhesus monkey enamel : sodium and magnesium had a low concentration at the enamel surface, wnereas chlorine had a high concentration there