Electron Probe Microanalysis of Noncarious Enamel and Dentin and Calcified Tissues in Mottled Teeth

Abstract

A quantitative chemical distribution of five elements in several undecalcified sections of teeth was determined by the electron microprobe method. The calcium (Ca)! phosphorus (P) weight percent ratios were determined in scans through the enamel and dentin, and characteristic curves for the concentration of the trace elements magnesium (Mg), sodium (Na), and chlorine (Cl) were obtained.The electron microprobe permits the qualitative and quantitative analysis of elements in a continuing or spot scan of an extremely smooth dental or other mineralized surface. This instrument has been widely and successfully used in the fields of metallurgy and geology and in the study of semiconductors. Smith and co-workers'-5 have developed correction formulae for quantitative analyses of chemically complex systems and have shown that values obtained are accurate within 1-5%.Several laboratories have been doing biological analyses using the microprobe from the time it was first marketed in this country. The earlier work was primarily on samples that could be analyzed for elements heavier than sodium and was generally limited to biologically hard parts such as bone.6 Hoerman et a17 have reported the uptake of tin and fluorine in human enamel in situ by the topical applications of stannous fluoride. Tin concentrations were determined by the electron microprobe, and fluorine (F) determinations were made chemically. Their report demonstrates the use of the electron probe for the analysis of certain elements in calcified tooth sections.Frank, Capitant and Gonis reported electron microprobe analyses of Ca, P, and Cl in anorganic tooth tissues impregnated with KI to establish uniformity in density, espe-

Calcium Distribution in Human and Bovine Surface Enamel

“…Quantitatively, the experimental values of 37.9 and 36.8 wt %> Ca in bovine and human enamel, respectively, concur strongly with the value 37.5 wt % > reported by Besic et al [1969] and Frank et al [1966].…”

Reversible high temperature exchange of carbonate and hydroxyl ions in tooth enamel and synthetic hydroxyapatite

“…One which can easily be taken into account is CI-for OH- (LeGeros, 1974). CI-is typically present to the extent of 0.3 wt % (Besic, Knowles, Wieman and Keller, 1969). By Vegard's law and the fact that for chlorapatite a = 9.644 ~, the presence of this much Cl-on the hexad axis would call for -0.01 expansion.…”

Posteruptive Maturation of Tooth Enamel Studied with the Electron Microprobe

“…The Na and Mg content of outer enamel is smaller than that of body enamel [Brudevold et al, 1960;Shaw and Yen, 1982;Robinson et al, 1981;Besic et al, 1969;Frostell et al, 1977]. However, the gradients reported up to now do not suggest that the Na and Mg content of the outer layer of tooth enamel is virtually zero.…”