Morphometric analysis of chronic inflammatory periapical lesions in root-filled teeth.

The cell distribution and the tissue composition of chronic inflammatory periapical lesions were analyzed from seventeen biopsies of root-filled maxillary canines and incisors. The specimens, which included the root tip, the soft granulation tissue, and portions of the surrounding alveolar bone, were subjected to a stereologic analysis based on morphometric point-counting procedures. Plasma cells and lymphocytes were found in large numbers (about 40 percent of the tissue volume) in areas close to the apical foramen. The number of fibroblasts and blast cells was comparatively low in this zone. Neutrophils, monocytes/macrophages, and mast cells accounted each for 1 to 2 percent of the infiltrated tissue volume. With increasing distance from the apex, the tissue examined harbored a decreasing number of inflammatory cells but an increased volume of noninfiltrated connective tissue. It was concluded that long-standing periapical lesions of root-filled teeth had many features in common with those of advanced inflammatory lesions of the marginal periodontium.