The Pathways of the Early Carious Process. I. Histologic Study

Abstract

Transverse sections through carious lesions from 13 permanent teeth were studied to determine the earliest pathways employed by the acid of caries. Sections were impregnated with mercury sulfide according to the method of Nishimura. Earliest impregnation occurred in the translucent areas at the edges of lesions. In such areas impregnation occurred largely in the sheaths at the periphery of the rods. In the more advanced regions of the lesion the core became progressively impregnated from its periphery toward its center, leaving the inter-prismatic substance unstained until last. The sheath was impregnated with Mercury Sulfide in an unerupted 3rd molar but not in sound enamel of posteruptive teeth, indicating that it represents that last area to calcify in development [long dash]existing largely as space or pathway until final calcification. Results indicate that this developmental pathway is reopened early in caries.