Repair processes in the cervical region of replanted and transplanted teeth in monkeys

The repair processes in the cervical region of replanted teeth where the periodontal ligament was injured by either extensive drying or removal was studied. These repair processes were related to various clinical factors, such as splinting, traumatic occlusion and exactness of repositioning. Permanent incisors were extracted, root filled extraorally and allotted to the following experimental groups: (1) PDL injured by drying, no splinting; (2) PDL injured by drying, splinting for 2 weeks; (3) PDL injured by drying, replanted tooth in traumatic occlusion; (4) PDL injured by drying, no splinting, non-exact repositioning of the replanted tooth; (5) PDL removed, no splinting. The animals were sacrificed 8 weeks after replantation and the replanted teeth examined histometrically. The different groups demonstrated area with normal periodontal ligament extending from 0.4 to 1 mm apically from the crestal margin, where the greatest extent was found in teeth with non-exact repositioning. The possible role of the gingiva in these repair processes is discussed.