Formation of new periodontal ligament around transplanted teeth with proliferating tissue in periodontal osseous defect under barrier membrane

Abstract

The present study evaluated whether transplanted proliferating tissue in periodontal osseous defects can form new periodontal ligament. A periodontal osseous defect was created in dogs by removing alveolar bone around the circumference of the premolar, and was covered with the membrane or without the membrane at control sites. After two weeks, the proliferating tissue in the periodontal osseous defect under the barrier membrane was excised, while at each control site, the connective tissue was dissected. The proliferating tissue and tooth were transplanted to holes drilled in the alveolar bone, while at the control sites, the connective tissue and tooth were transplanted. After one, two and four weeks, the dogs were sacrificed and examined histologically; a LightCycler was also used to measure the mRNA expression of vascular endothelial growth factor (VEGF) and alkaline phosphatase (ALP) in the transplanted tissues. VEGF and ALP mRNA expressions were significantly increased in the transplanted proliferating tissue compared with the connective tissue (control). The root transplanted bearing the proliferating tissue formed new periodontal ligaments, whereas connective tissue could be observed on the root surface in the controls. The results of this study show that transplanted proliferating tissue promotes the formation of new periodontal ligaments around the root.