[Use of dysprosium considered as an activable tracer in the study of tooth structures]

After 32 days of administration to rats of dysprosium in drinking water, this element has been studied by neutron activation analysis in the intra-oral part of the incisors as well as in the molar crowns. This element was absent in the intra-osseous parts of the incisors, the femurs and the liver. After intravenous injection of 13 mg or 26 mg of Dy in several doses over 32 days, this element was found in the incisor formation and maturation zones as well as in the part having erupted in the oral cavity. It was also found in the molars, the femurs and the liver. The structural study has shown that no cytotoxic effect was observed with the dysprosium doses used. Dentinogenesis and amelogenesis were not disturbed. The final structures were homogeneous. By comparing the two administration ways of dysprosium we have at our disposal a study model using an inducible tracer of the incorporation of adsorption of a mineral element in dental structures during early or late maturations.