Histological Study of Long Junctional Epithelium

-Interaction of Epithelial and Connective Tissue Reattachment following Flap Surgery-

Abstract

The purpose of this study was to elucidate interaction of the long junctional epithelium and connective tissue attachment to the root surface after periodontal surgery.
Four beagle dogs were used. After a full-thickness mucoperiosteal flap was made, the buccal cortical bone of premolars was removed. Then, denuded dentin surfaces were produced to remove the cementum. The roots were divided into two groups. One group was produced by covering the exposed bone surface adjacent to the roots with polycarbonate membrane while in the other group it was not. The flap was repositioned and sutured. Animals were sacrificed 2, 4 and 8 weeks after surgery and periodontal tissues were histopathologically examined.
1. In the bone-covered group, the regenerative junctional epithelium (RJE) migrated apically along the denuded dentin surface at 4 to 8 weeks. New cementum formation was not observed.
2. In the non-bone-covered group, the RJE migrated apically at 4 weeks. New cementum formation was observed at the apical region of the denuded dentin surface. At week 8, cementogenesis extended coronally with coronal reduction of the RJE.