CHANGES IN THE CYTOSKELETON OF CELLS WITHIN THE PERIODONTAL-LIGAMENT AND DENTAL-PULP OF THE RAT FIRST MOLAR TOOTH DURING AGING

The periodontal ligament and dental pulp connective tissues are foetal -like, and their process of ageing may therefore differ from other tis sues of mesenchymal origin. Several studies have already highlighted t he lack of age changes in the extracellular matrix (ECM), but more nee ds to be known about cellular changes. For this study, tissues from th e first molar teeth of Wistar rats aged 12 wk and 104 wk were compared by immunolocalisation of cytoskeletal components. Tissues from the fi rst molar were immunostained, employing a panel of 16 monoclonal antib odies against cytokeratins, vimentin, F-actin and tubulin. Within the pulp, labelling for vimentin in both odontoblasts and pulpal fibroblas ts and F-actin in the cell processes of odontoblasts was detected at b oth ages but with marked reduction in labelling in the older tissue. W ithin the periodontal ligament, vimentin labelling was weaker in the a ged tissue, especially nearer the cementum. More significantly, the fi broblasts of the aged periodontal ligament expressed cytokeratin 19. I n contrast to reports of little age change to the ECM, the cells of th e pulp, and particularly the periodontal ligament, show marked changes to their cytoskeletal components.