Journal of Dental Research, Vol 70, 123-126, Copyright © 1991 by International & American Associations for Dental Research Online Journals
The effect of EHDP concentration on enamel demineralization in vitro
J. Christoffersen, M. R. Christoffersen, J. Ruben and J. Arends
Panum Institute, University of Copenhagen, Denmark.
The depth of caries lesions produced in bovine enamel situated in an
unstirred 0.1 mol/L lactic acid buffer at pH 4.5 has been studied as a
function of time and of concentration of the inhibitor ethane-1-hydroxy-1,
1-diphosphonate, EHDP. At concentrations of EHDP up to 5 mmol/L, the lesion
progress decreased with increasing concentration of inhibitor. At higher
concentrations, the opposite effect was observed. At low inhibitor
concentration (0.1 mmol/L), the lesion depth to the third power varied
linearly with time. At intermediate concentrations (0.25-5 mmol/L), the
square of the lesion depth varied linearly with time. At high inhibitor
concentrations (25-100 mmol/L), the lesion depth varied linearly with time.
It was also shown that the rate of dissolution of calcium hydroxyapatite
crystals was retarded by low concentrations of EHDP, but accelerated by
high concentrations of EHDP. The results are related to a physico-chemical
model describing lesion formation.
