Effect of oscillating fluoride doses on fluorosis development in rats

57th Congress of the European Organization for Caries Research (ORCA), Caries Research, Montpellier, France, 2010

Abstract

The effect of fluoride (F) on animals exposed to constant chronic F doses is well known, but there is no information about the effect of chronic oscillating doses, to which human are commonly exposed, what was evaluated in the present study. The study was approved by the Animal Ethics Committee of UNICAMP. Twenty 35-days-old Wistar female rats received water with constant F concentration at 0, 12.5, 25 or 37.5 μg F/ml or oscillating at every 72 h between 12.5 and 37.5 μg F/ml (mean exposure equals to 25 μg F/ml). After 78 days, animals were sacrificed, and F concentrations in plasma and femur were determined. Dental fluorosis score in the rat incisor was estimated by an image analysis method based on the intensity of the pigmented banding on the surface of incisors. Fluorosis scores were (mean ± SD, n = 4) 1.1 ± 0.3, 1.7 ± 0.6, 2.9 ± 0.7, 4.1 ± 0.9 and 2.8 ± 0.7 pixel values respectively for groups 0, 12.5, 25, 37.5 and oscillating. F concentrations in plasma were 2.1 ± 0.3, 4.3 ± 0.5, 5.5 ± 1.7, 7.5 ± 2.4 and 5.9 ± 0.8 μM , and in the bone, 249.2 ± 91.5, 714.9 ± 41.8, 1,016.9 ± 105.7, 1,555.7 ± 112.2 and 1,082.7 ± 108.6 μg F/g dry weight, respectively. A significant linear increase in the variables values was observed according to the increase in F concentration in the water for the constant groups (p < 0.0001). No difference between the group which received oscillating doses and the group receiving 25 μg F/ml was observed (ANOVA, p > 0.05). The results suggest that the biological effect of F on animals chronically exposed to symmetrical oscillating F doses may reflect the effect of the mean of the oscillating doses.

BibTeX

@inproceedings{catani10orca,
    authors      = “Danilo B. Catani and L{\’\i}via M. A. Tenuta and Fernanda A. Andal{\‘o} and Jaime A. Cury”,
    title        = “Effect of oscillating fluoride doses on fluorosis development in rats”,
    booktitle    = “57th Congress of the European Organization for Caries Research ({ORCA}), Caries Research”,
    volume       = 44,
    year         = 2010,
    address      = “Montpellier, France”,
    note         = “short paper”,
}