Zinc deficiency-induced changes in the lipid composition and ultrastructure of rat incisor teeth.

The lipids and ultrastructure of the forming, maturing and erupted parts of incisors were compared in rats fed a zinc-deficient diet for 28 days, pair-fed rats and control rats. The lipid levels in the forming portions of zinc-deficient incisors were 30-50% below control levels and were associated with longer Tomes' processes in the secretory ameloblasts, porosities in the forming enamel and fewer malachite green-aldehyde-phospholipid aggregates in the predentine. No marked structural changes were seen in the erupted portions of the teeth, although variations in lipid composition were detected both in the maturing and erupted parts. No differences were found between teeth from the 3 groups of animals for Na, Mg, Cl, Ca and P signals with the electron microprobe.