[Effect of epidermal growth factor (EGF) on proliferation of the cells derived from the root resorbing tissue of human deciduous teeth].

The resorption of the roots of deciduous teeth is a physiological phenomenon. Many morphological and histological investigations of the root resorption have been reported. However little biochemical data concerning systemic factors in it are available. In this study, cell culture derived from the root resorbing tissue of human deciduous teeth was tried and the effect of EGF on that cell was examined. The dissected root resorbing tissue from human deciduous teeth was cultured in a medium containing 10% fetal calf serum in a humidified incubator at an atmosphere of 5% CO2 in air at 37 degrees C. The outgrowing cells from root resorbing tissue were a mixed population of mesenchymal cells and epithelial cells during the early stage of cultivation, but at the later stage they changed to morphologically single population. The mesenchymal cells seemed to be derived from the dental sac and the epithelial cells from the enamel organ or the oral mucoepithelium. These cells seemed to be useful for analysis of the systemic factors in the root resorption. The effect of EGF on the proliferation of cells obtained as stated above was examined. EGF markedly stimulated DNA synthesis about by a factor of 6.9 for the mesenchymal cells and by a factor of 3.4 for the epithelial cells. These results suggested that EGF participates in the root resorption of human deciduous teeth.