The effect of excessive occlusal trauma upon periodontal healing after replantation of mature permanent incisors in monkeys.

The effect of excessive occlusal force upon periodontal healing after replantation of mature permanent incisors was studied in green Vervet monkeys. The extra-alveolar period before replantation was 120 min. Prior to replantation, the teeth were root filled with gutta percha. The material consisted of four groups. In the two control groups, either no splinting or splinting for 2 weeks was used. In the first experimental group, a stainless steel crown was cemented on the antagonist of the replanted tooth, thus elevating the bite 1--2 mm. In the second experimental group, an orthodontic band was cemented onto the replanted tooth, also elevating the bite slightly. All bite elevations were removed after 6 weeks. The animals were sacrificed 8 weeks after replantation and the replanted teeth were examined histometrically. Replacement resorption (ankylosis) was found with the same frequency and extent in all groups. However, a significant difference was found in the pattern of replacement resorption activity among the experimental groups. Thus, active replacement resorption was more common in the groups with no splinting or traumatic occlusion as compared to the splinted group. Furthermore, linear replacement resorption, a process which apparently removes established ankylosis areas, was significantly more frequent in the non-splinted groups than in the other groups. It is concluded that excessive occlusal forces cannot prevent or eliminate ankylosis in replanted teeth after prolonged extra-alveolar dry storage.