Connective tissue reattachment as related to presence or absence of alveolar bone

The present study was designed to examine if alveolar bone, located adjacent to a root surface deprived of its periodontal ligament and cementum layer, can stimulate the reformation of a connective tissue attachment. The maxillary and mandibular incisors in 3 monkeys were extracted. Immediately after tooth extraction, the buccal root surfaces of the incisors from the left side of the jaws were planed by means of curettes to a level corresponding to half the root length. All teeth were then reimplanted into their original sockets. However, before tooth reimplantation, the buccal alveolar bone plate was removed in 2 of the monkeys to a level corresponding to half the depth of the sockets. The animals were sacrificed 6 months after the reimplantation procedure. The jaws were removed and histological sections of the experimental teeth and adjacent periodontal tissues were produced. The sections were analyzed in the microscope and subjected to histometric measurements. The results demonstrated that, irrespective of the presence or absence of alveolar bone, a fibrous reattachment failed to form on that part of the reimplanted teeth which had been deprived of their periodontal ligament. This indicates that alveolar bone located adjacent to a root surface may have limited influence on the biological conditions which determine whether periodontal healing results in connective tissue reattachment or new attachment.