ABSTRACT
Dental caries has become one of the important public health problem in the developing countries [Mel nichenko and Tristen, 1994]. The percent of children with no caries teeth varies inversely with age. Food and water are the principal sources of fluorine intake. After absorption, fluoride go to the blood and it accumulates in all hard tissues. The most sensitive tissue in the body to excessive ingestion of fluoride is the ameloblastic layer which forms the organic frame work of the enamel [Seppa et al., 1998]. In higher doses, fluorine can be injorious, disturbing enamel formation and causing mottled enamel [Toth, 1990]; Radioisotopic studies showed that enamel and dentin are permeable to water and to various inorganic ions [Sognnaes et al., 1955]. During the developmental period, while the tooth is growing and calcifying, nutritional deficiencies of vitamins [A, C and D], calcium, phosphorus and fluorides result in abnormalities of the chemical composition of the tooth, and may lead to dental caries [WHO, 1998]