Journal of Dental Research, Vol 72, 1599-1603, Copyright © 1993 by International & American Associations for Dental Research Online Journals
A single-section model for enamel de- and remineralization studies. 1. The effects of different Ca/P ratios in remineralization solutions
R. A. Exterkate, J. J. Damen and J. M. ten Cate
Department of Cariology and Endodontology, Academic Centre for Dentistry Amsterdam (ACTA), The Netherlands.
A prerequisite for the accurate measurement of differences between pre- and
post-experimental mineral profiles in single sections by quantitative
microradiography is a high degree of reproducibility of the analytical
procedures. We have determined the reproducibility of both the production
and analyses of microradiographs. Lesions were made in seven single bovine
enamel sections and radiographed three times. Each microradiograph was then
analyzed on three different occasions by use of an image analysis system.
This resulted in only small standard deviations in the lesion parameters.
The method was used to determine the sites of mineral deposition in lesions
in single sections during remineralization in three different solutions,
one of which contained 1.5 mmol/L Ca and 0.9 mmol/L PO4 (standard
solution); the other two solutions were low in either Ca or PO4, but all
three had the same degree of supersaturation. The mineral profiles and
lesion parameters were determined after lesion formation and after
remineralization for 4 days, 1, 2, and 3 weeks. The decrease in IML
(integrated mineral loss) in the lesions remineralized in the standard
solution was greatest during the first week. Lesion profiles revealed that,
under non-standard conditions, mineral deposition was retarded in the
deeper part of the lesion, in contrast to the even distribution of mineral
deposition from the standard solution. Differences in IML changes and
lesion profiles between these bovine enamel experimental groups diminished
when remineralization continued for 2 and 3 weeks. Possibly, the reactivity
of mineral surfaces in newly made lesions affected the diffusion of
remineralizing ions from low concentration solutions to the lesion front.
