A HISTOCHEMICAL-STUDY OF THE BEHAVIOR OF MACROPHAGES DURING EXPERIMENTAL APICAL PERIODONTITIS IN RATS

The behavior of macrophages from experimentally induced periapical les ions of rats was studied in paraffin sections using nonspecific estera se and a monoclonal antibody, ED1. Macrophages were seen near the regu larly arranged osteoblasts in controls and the detached osteoblasts at the initiation phase of bone resorption. In addition, numerous macrop hages were widely distributed throughout the periodontium at the activ ation phase of bone resorption. On the other hand, macrophages were ra rely seen near the bone formation surfaces, but large numbers of macro phages were localized in microabscess at the activation phase of bone formation. It is suggested that macrophages may plat an important role in activation of osteoclastic bone resorption and inhibition of compl ete bone repair in bone remodeling during experimental apical periodon titis.