Electron Microscopy of the Enamel of Teeth in Various Stages of Development

Abstract

Thin sections for electron microscopy were made from demineralized and undemineralized mouse and monkey enamel in various stages of development. The specimens were embedded in plastic and sections cut on a rotary microtome equipped with a thermal expansion adapter and glass knives. Newly-formed enamel matrix appeared homogeneous in structure. During maturation, a transition to fibrillar structure was noted. In regions where the transition had recently been completed, the fibrils were very closely packed together. In fully-developed, completely calcified enamel the fibrils were widely spaced and apparently thinner. Minute crystal-like particles were observed in sections of un- demineralized, partly calcified monkey enamel.