Type-I-collagen expression in rats tooth germs modified by fluoride

Type-I-collagen the main component of dentin extracellullar matrix forms the specific, spatially organized scaffold for the mineral deposition. “Objectives:” since fluoride has been confirmed as the factor, which alters the type-I-collagen formation the aim of our study was to investigate potential changes in the type-I-collagen expression in the first molar tooth germ of rats at 1-4 days of postnatal life (P1-P4), supplemented with fluoride in drinking water during pre- and postnatal life. “Methods:” Sperm-positive rats,fed with standard diet were randomly divided into three groups and from the fifth day of pregnancy watered with: tap water (C), water with low (Fl) and high (Fh) fluoride concentration, respectively. Immunohistochemical methods and Sirius Red F-3BA staining were used to visualize type-I-collagen under the BioRad confocal system polarized Nicon Elipse Endo microscope, respectively. The quantitative differences were assessed with Western Blot analysis. Additionally, fractal analysis was done. “Results:” The type-I-collagen-ir in all P1 groups was similar. We observed the changes in immunoreactivity between younger and older animals from the same “water group” in time. The increased differences in immunoreactivity among older animals from different “water groups” the same age was also conspicuous. The positive type-I-collagen-ir was detected in predentin and dental pulp cells. In older animals the predentin reactivity for type-I-collagen was stronger than in younger groups. The weak type-I-collagen-ir appeared also in odontoblasts in all P4 groups. In the Sirius Red method predentin stained also the most in P4 rats from Fh group. The width of the mineralizing front in Fh groups each age was wider than those from other groups. The higher type-I-collagen concentration in groups treated with high fluoride concentration was confirmed by Western Blot examination. “Conclusions:” High fluoride supplementation during early stages of odontogenesis alters the type-I-collagen expression in rats molar tooth germs.