1997 Volume 39 Issue 2 Pages 167-183
The purpose of this ultrastrctural study inves-tigated regenerative connective tissue attachment by guided tissue regeneration in mongrel dogs.
On the buccal aspect of the mesial roots of premolars, bony defects were created by removing buccal bone to a level of about 5mm in depth from the cemento-enamel junction. In order to inhibit bone growth, defects were filled with rubber base impression materials before suturing. Four weeks later, the mucoperiosteal flaps were elevated again and the impression materials were carefully removed. Scaling and root planing were performed, and then sterilized and well-adjusted expanded polytetrafluoroethylene membranes were applied to cover the bony defects and fixed firmly with sling sutures. Flaps were then closed with interrupted sutures. The membranes were removed 6 weeks later. Untreated teeth were used as controls. Observation periods were 14, 22 and 30 weeks after the membrane application. At the end of each observation period, animals were sacrificed for specimen preparation. Light microscope, transmis-sion electron microscope and scanning electron microscope were utilized for the histological obser-vations.
Different amounts of dentin were scraped by scaling and root planing. New cementum were formed in these spaces in all the specimens. At the dentino-cemental junction, the intrinsic collagen fibers of cementum were intermingled with the matrix fibrils of dentin.
Collagen bundles inserted into new cementum could be divided into 3 groups by their origin. The bundles at the coronal third region originated from the gingival connective tissue. Those at the middle region originated from both the gingival connective tissue and the periodontal ligament. Those at the apical third region originated from the periodontal ligament.
These results indicated that the tissue regenerat-ed by GTR had specific connective tissue attach-ment which included newly formed cementum.
