This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Pearce, E.I.F. Articles by Nelson, D.G.A. Search for Related Content PubMed PubMed Citation Articles by Pearce, E.I.F. Articles by Nelson, D.G.A. Social Bookmarking                         What's this?

Microstructural Features of Carious Human Enamel Imaged with Back-scattered Electrons

Dental Research Unit, Medical Research Council of New Zealand, P. O. Box 27007, Wellington, New Zealand

D.G.A. Nelson

Dental Research Unit, Medical Research Council of New Zealand, P. O. Box 27007, Wellington, New Zealand

We have used back-scattered electrons (BE) in the scanning electron microscope to produce mineral density images of enamel. Flat surfaces of artificially-carious enamel, softened in an intra-oral experiment, and naturally-carious (white spot) enamel were polished to a high gloss with diamond lapping compound, rendering them almost featureless by secondary electron scanning electron microscopy. They were then examined at 10 to 30 kV in a Philips 505 instrument fitted with a 4-quadrant BE detector. Study of surfaces prepared approximately parallel to the natural surface showed that mineral was lost from both prism core and the interprismatic region, leaving a thin mineral-rich rim at the prism periphery. The same lesions viewed longitudinally on a surface prepared perpendicular to the natural surface showed mineral-rich bands at the prism margins in the outer enamel. Near the advancing front of the lesion, the prism junctions were widened and the prism cores sometimes hypermineralized. Natural lesions sectioned in the prism long axis showed features previously seen with other techniques, e.g., cross-striations and striae of Retzius, but in much greater detail. Mineral enrichment at the prism periphery in the lesion body and a widening of the prism junction at the advancing fronts of lesions in permanent teeth were most obvious. Calculations showed that with an accelerating voltage of 30 kV, the images reflected mineral density up to 4 µm beneath the surface. BE microscopy produces a high-resolution image of mineral loss or gain in carious enamel, with relatively easy sample preparation.

Journal of Dental Research, Vol. 68, No. 2, 113-118 (1989)
DOI: 10.1177/00220345890680020301


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?