Journal of Dental Research, Vol 66, 1587-1590, Copyright © 1987 by International & American Associations for Dental Research Online Journals
The short-term uptake and retention of fluoride in developing enamel and bone
J. W. Bawden, T. G. Deaton and M. A. Crenshaw
Eight- and 12-day-old rat pups were injected intraperitoneally with
fluoride. Plasma, molar enamel, and bone samples were collected at
observation times up to six hr after injection. In a second series, adult
rats maintained for six weeks on water containing 5 ppm F were injected
with fluoride. Plasma, incisor enamel, and bone samples were collected at
the same observation times as those used in the first series. Fluoride
assays were conducted by means of the microdiffusion,
ion-selective-electrode method. In the suckling rats, plasma [F] levels
peaked at 15 min and returned nearly to baseline in one hr. Significant
increases in the [F] of developing enamel and bone were observed. No
significant decline from the peak [F] seen in the hard tissues was observed
over the six-hour period. Similar results were seen in the developing
enamel of the adult rats. The data gave no evidence of a short-term
reversible component of fluoride uptake in developing enamel. Apparent
increases in F uptake in enamel and bone beyond peak plasma values suggest
the presence of a diffusion-limiting membrane for fluoride from the
extracellular fluids into the mineralizing matrix.
