Correlated Electron Probe Microanalysis and Microradiography of Carious and Normal Dental Cementum

Abstract

In order to compare the distribution of elements in carious cementum and root dentin with the morphology of the lesion, a correlated electron probe microanalysis and microradiographic study was carried out. Ground sections of human teeth showing early stages of root suface caries were microradiographed and subsequently analyzed for the presence of Ca, P, F, S, Mg, Na, Fe, Cu, Zn Sn, and Ag. The results show that caries in cementum starts as a partial decalcification which soon reaches the peripheral dentin and may extend to a depth of a third of a millimeter without any loos of surface contour at the light microscopic level of observation. The pattern of dissolution and reprecipitation of mineral components seems to follow the pattern seen in dentin caries. Although reprecipitation of mineral forming a hypercalcified layer at the surface of the lesion occurs regularly, a surface layer of increased radiopacity may be found even in the absence of this process due to the adsorption of foreign, heavy elements in the surface layer of carious cementum. The relatively high F content normally found in the outer layer and the additional accumulation of F in this layer both from saliva and incident to the outward diffusion of dissolved mineral, result in the development of a particularly distinct zone of recalcification at the surface during the early stages of cementum caries.

Effect of Topical F^–– Solutions on Caries-Like Lesions in Root Surfaces

“…The Mg criterion is seen to give somewhat greater depths than the micrograph assessment which is probably connected with shade and scale uncertainties in the latter technique. That Mg is strongly leached out in artificial caries lesions has also been observed earlier in work on dentin [Hals and Selvig, 1977] and in SIMS studies on enamel [Loddinget al, 1985].…”

Ultrastructural Study on Human Root Caries

“…With microradiography, the initial carious lesion in cementum appeared to involve subsurface demin eralization with a relatively intact surface layer some what akin to the early enamel lesion [Furseth and Jo hansen, 1968;Westbrook et al, 1974;Hals and Selvig, 1977]. In the present study, we could not correlate these microradiographic findings with our SEM and TEM observations.…”

Fluoride Distribution in Sound and Carious Root Tissues of Human Teeth

“…These include a hypermineralised surface layer [Hals and Selvig, 1977], irritation dentine on the pulpal wall [Schüpbach et al, 1990a] and dentine sclerosis beneath a lesion [Schüpbach et al, 1992]. However, enamel 'undermining' at the CEJ noted by Schüpbach et al [1992] was also seen in our study ( fig.…”