Presence of interleukin-4-producing cells for human bone regeneration after application of guided tissue regeneration membranes

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.