[Ultrastructure of the ligamental surface of the rat alveolar process]

The ultrastructural study of the alveolar bone surface of adult rat molars has shown the presence of resting, developing and resorbing areas. Intermediary, tight and gap junctions were observed between the cell processes of osteoblasts and osteocytes. In developing zones, the progressive differentiation of bone lacunae was followed. In resting zones, fibroblast-like cells with large intercellular spaces were observed. The ultrastructure of the osteocytes and the organic periosteocytic space was variable. The osteoclastic resorption showed an initial mineral attack followed by a collagen breakdown. Some observations suggested a relationship between the osteocytes and the origin of the osteoclast.