Analysis of calcium, phosphorus, and carbon concentrations during developmental calcification of dentin and enamel in rat incisors using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX)

摘要

Objective The study was designed to investigate the concentrations of calcium (Ca), phosphorus (P), and carbon (C) during developmental calcification of dentin and enamel in rat incisors. Methods Mandibular incisors from eight 2-week-old male Wistar rats were analyzed by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). We analyzed data on the elements in the course of developmental processes in dentin and enamel and along the vertical line of the matrix between odontoblasts and ameloblasts. Results The dentin concentrations of Ca and P and the Ca/P ratio were the lowest, while the C concentration was the highest in initial dentin. The Ca and P concentrations were the lowest, whereas the C concentration was the highest in predentin along the vertical line; the Ca/P ratio did not show any differences. The concentrations of Ca and P increased, while the C concentration decreased during early maturation and more so in late maturation in developing enamel, while the Ca/P ratio increased during late maturation. The Ca and P concentrations and the Ca/P ratio were the highest, while the C concentration was the lowest in enamel adjacent to the junction with dentin on the vertical line. Conclusions During tooth development, the initial dentin matrix may possess distinctive mineral characteristics as compared with other parts of dentin and predentin. Elemental composition of the mineral in enamel may change during late maturation. Our results are suggestive of degradation of organic components during developmental calcification in dentin and enamel.