Application of the scanning electron-probe X-ray microanalyser to dental tissues

Six premolar teeth, from patients aged11 to 15 years, were used in a study of peritubular and intertubular dentin in the crown and root. Anelectron microprobe with an associated scanning electron microscope was used to determine simultaneously the concentrations, in weight %, of calcium, phosphorus and magnesium, using a beam size of approximately 0.25 μm diameter. Coronal peritubular dentin was hypermineralized (total of Ca: P and Mg) by up to 9% by weight though usually this was between 2 and 4 %. Radical peritubular dentin was either hypo- or isomineralized in these young teeth when compared to the intertubular dentin. In most teeth the coronal dentin was more highly mineralized than the radicular dentin in both peritubular and intertubular area. Analysis of the data showed that there was a significantly greater variability of calcification in the peritubular dentin. These results are discussed particularly in relation to the microradiographic data which are available on dentin.

Section: Formation Oj Ptdcontrasting

confidence: 92%

“…Boyde et al [8] demonstrated in a semiquantitative way with the electron microprobe that there was approximately 10 %> more calcified matter in peritubular dentin. The young human teeth that were used were of an unspecified age and from an unspecified part of the tooth.…”

Section: Introductionmentioning

confidence: 99%

Inorganic Components of the Peritubular Dentin in Young Human Permanent Teeth

Miller

Eick

Neiders³

1971

“…The instrument utilizes the property of X-ray emission which results from the bom- bardment of the electron beam. The principles of the microprobe technique have been described by various authors [Boyde et al, 1961;F razier, 1967]. The X-rays emitted originate from atoms up to a depth of about 3 itm below the cut surface.…”

Section: Methodsmentioning

confidence: 99%

Calcium Distribution in Human and Bovine Surface Enamel

Davidson¹,

Boom²,

Arends³

1973

In this investigation, the calcium content of sound decalcified and etched enamel was measured with an electron microprobe. The results show that calcium content, as a function of depth, decreases only a few percent as a result of decalcification in gelatin solutions of pH 4 and 5 within 1–8 days. Subsurface lesions (with a relatively low Ca concentration) could be observed. These lesions penetrated under the enamel surface at a rate proportional to the square root of the decalcification time. In etched enamel, however, the Ca decrease observed (also a few percent) was uniform over the whole penetrated area.

“…The electron probe X-ray microanalyser, which is generally employed in metallurgy and mineralogy, has been applied in the biological field for the topographic detection of relatively heavy elements [Boyde et al, 1961;Brooks et al, 1962;T ousim is, 1963;Baud et al, 1963;M ellors et al, 1966;F razier, 1967;Rosser et al, 1967], and more recently even for light elements [On g , 1966; , On the other hand, the high resolution obtained in crystallographic anal ysis by X-ray diffraction is, due to the recent refinement, sufficiently sensitive ( ± 0.001 A) to detect the small modifications of dimension brought about by ionic substitution.…”

mentioning

confidence: 99%

Electron Probe and X-Ray Diffraction Microanalyses of Human Enamel Treated in vitro by Fluoride Solution

Baud

Bang²

1970

Fluoride uptake, topographic distribution, and effect on human dental enamel following topical treatment (for 4 min, 8 min and 72 h) with an acidulated fluoride-phosphate solution have been studied by means of electron probe X-ray microanalysis and X-ray diffraction. The samples examined were divided into a non-washed group, and a washed group from which excessive and loosely bound F had been eliminated from the enamel. The topographic distribution of fluorine was demonstrated by electron probe X-ray microanalysis. In the non-washed samples, an outer layer with a higher concentration of F, and adjacent to this another layer having a moderate concentration of F, were observed. After a prolonged washing about 90% of F of the outer layer was eliminated, whereas that of the inner layer persisted. X-ray diffraction analysis shows the presence of CaF₂ in non-washed samples; the lines of CaF₂ disappear after prolonged washing. On the other hand, a displacement of the apatite lines was observed in all treated samples, corresponding to a shortening of the parameter a of the unit cell, due to the replacement of the OH^–– by F^–– in the crystalline network. These results show that by topical treatment of enamel with an acidulated fluoride-phosphate solution, an accumulation of F in the surface layers of the enamel is produced, partly as CaF₂ and partly as fluorapatite.