RECOMBINATION OF EPITHELIAL ROOT SHEATH AND DENTAL PAPILLA CELLS IN-VITRO

Hertwig's epithelial root sheath (HERS) cells were isolated and recomb ined with ectomesenchymal cells in vitro utilizing extracellular matri x components as substrate. After 14 days in culture, HERS cells were d ifferentiated and exhibited a stratified organization. These features resembled those observed in vivo as epithelial rests of Malassez. A mi neralization process was also present in HERS cells, in which calcium salts were deposited. This mineralization was correlated with the stro ng immunoexpression of osteopontin by HERS. The results obtained add s upport to the possible role of HERS in the secretion of hypocalcified material on the root during early cementogenesis.