Cellular dynamics on the pressure side of the rat periodontium following experimental tooth movement

Publisher Website
Google Scholar
Abstract
The maxillary right first rat molar was moved in a lateral direction with a continuous force of approximately 20 g for 2 d with the aim to study the cellular response following hyalinization of the periodontal membrane. Twenty‐four animals were flash‐labeled and subgroups of 3 animals were sacrificed 1 h, 1, 2, 3, 4, 5, 6, and 7 d after removal of the orthodontic appliance. In a second series comprising 14 animals, 9 animals received the isotope injections at the removal of the orthodontic appliance, and were sacrificed after 12 h, 1, 2, 3, 4, 5, 6, 7, and 9 d. In the other 5 animals injections were given 3 d after removal of the orthodontic appliance, and these animals were sacrificed 1, 2, 3, 4, and 5 d after the injection. The radioactive index of the flash‐labeled animals were characterized by a bimodal shape. The first increase in labeling was ascribed to the reaction of cells around the hyalinized areas and the second increase to cells invading the hyalinized tissue. In most cells of the second series the labeling intensity decreased with increasing time between injection and sacrifice, but in other cells the isotope remained more undiluted. Osteoclasts with labeled nuclei were observed 1, 2, 3, 4, 6, and 7 d after injection. The number of labeled osteoblasts and fibroblasts increased initially whereas the number of labeled cementoblasts decreased.