|| Checking for direct PDF access through Ovid
To study the process of bone regeneration we examined three samples of periapical regenerative tissue obtained from two patients under a guided tissue regeneration treatment in endodontic surgery by the immunohistochemical and enzyme histochemical methods. The regenerative tissue consisted of a large number of fibroblast-like cells and a small number of mononuclear cells. Fibroblast-like cells stained positively for alkaline phosphatase and osteopontin, whereas mononuclear cells stained positively for CD4. Interleukin-4-producing cells could be detected in adjacent sections. However, interferon-γ-producing cells could not be detected. These findings suggest that interleukin-4-producing cells may be one of the elements associated with success in the human bone regeneration process in vivo.