Periodontal ligament and cementum are important parts of the tooth-supporting apparatus. However, the mechanism behind the ability of the periodontal ligament to produce cementum and to maintain a non-calcified fibrous tissue between the root of a tooth and the alveolar bone is not fully understood. A part of the calvarial periosteum seems to share developmental similarities with the periodontal ligament with regard to cell types and morphology. The aim of this study was to compare the ability of two types of allogeneic periosteum to form a periodontal ligament-like structure around allogeneic transplanted teeth in alveolar bone.
Materials and Methods:
Teeth for transplantation were extracted from adult beagle dogs. The crown, cementum and periodontal ligament of the extracted teeth were removed. Periosteum was obtained from the calvaria and tibia in three-month-old beagle dogs. The roots were wrapped with the calvarial periosteum (CP group), tibia periosteum (TP group), or surgical collagen sheets (SC group) and were transplanted into surgically created bone cavities in edentulous sites. Roots only were transplanted as a control group. The transplanted teeth were completely covered with a submerged barrier membrane.
Histomorphometrical analysis was performed at 24 weeks after surgery. New cementum formation was not observed in any of the groups. More substantial connective tissue adhesion occurred around the transplanted roots of the CP group as compared with the TP, SC, and control groups.
The calvarial periosteum seems to possess the same competency as periodontal ligament tissue with regard to the maintenance of non-calcified tissue between tooth and alveolar bone. However, cementum formation may be a unique ability of the periodontal ligament.
periosteum, periodontal ligament, cell differentiation, cement formation, neural-crest derived mesenchyme, non-calcified tissue