Cell proliferation in developing human dental pulp A combined flow cytometric and immunohistochemical study

Information concerning cell proliferation and differentiation in dental pulp may be important to understand tooth response to exogenous stimuli. Since few data concerning human dental pulp are available, we have investigated the growth fraction and the localization of proliferating cells in pulp tissue of third molars of young adult human males and females, using flow cytometry and immunohistochemistry. Flow cytometric analysis demonstrates a low proliferative activity of pulp tissue that appears to be confined to radicular pulp, as revealed by immunohistochemical detection of proliferating cells. No polyploid or aneuploid cell populations could be identified, and G2-blocked cells, if any, represented a negligible cell population. Odontoblasts, cells of the sub-odontoblastic layer, and cells of coronal pulp were found to be not proliferating under normal conditions. These data provide the basis for future investigations on proliferative activity and regenerative potentiality of human pulp cells in experimental and clinical situations.