Vascular reactions in the periodontal ligament incident to trauma from occlusion

Abstract The experiments were performed in 13 dogs; nine of the animals had initially a healthy periodontium and four had experimental periodontitis. Trauma from occlusion was created in all dogs according to a technique described previously. The dogs were sacrificed after 7, 14, 30 and 180 days of the experiment. Prior to sacrifice colloidal carbon was injected intravenously. The degree of vascular labelling and leucocyte infiltration as well as osteoclastic activity and the size of the marginal periodontal ligament were assessed in biopsy sections. The findings showed that dogs with a healthy periodontal lesion (Group A) differed in their reactions to a jiggling type of occlusal trauma when compared to dogs with an established periodontal lesion (Group B). Whereas the periodontal ligament in Group A had become adapted to the altered occlusion by the end of 6 months of experiment, that of Group B still showed increased vascular leakage, leucocyte migration and osteoclastic activity.