Histologic and autoradiographic evaluation of long term gingival wound sites in adult rats

Eight Sprague-Dawley male rats were injured at the gingival papillae mesial to the maxillary left first molars. Groups of these rats and controls were sacrificed 9 and 12 months after injury. Prior to sacrifice, all animals received 0.5μc of tritiated thymidine per gram body weight by intraperitoneal injection. Jaws were dissected out and prepared for histologic and autoradiographic analysis. Measurements at the wound and respective control sites indicated accelerated gingival recession at the sites of injury. Labeling indices, however, were similar at both areas examined. Within the limits of the experiment, the observations suggest similar functional demands at both sites regardless of the position of the marginal gingiva, but do not determine the reason for accelerated gingival recession at the wound sites with time.