Potentiality of periodontal tissue regeneration on periodontal defect.

1986 Fiscal Year Final Research Report Summary

• Project/Area Number: 60570895
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Conservative dentistry
• Research Institution: KAGOSHIMA University
• Principal Investigator: YOKOTA Makoto KAGOSHIMA University of Dental School, 歯学部, 助教授 (40107298)
• Co-Investigator(Kenkyū-buntansha): HAMADA Atsuko KAGOSHIMA University of Dental School, 歯学部, 助手 (20180937) ; KUROKI Kiyoshi KAGOSHIMA University of Dental School, 歯学部, 助手 (80170108) ; NAKAYAMA Kiyotaka KAGOSHIMA University of Dental School, 歯学部, 助手 (20164361)
• Project Period (FY): 1985 – 1986
• Keywords: periodontal ligament / root resorption / new cementum / クエン酸

Research Abstract

In order to find how width of the periodontal defects occuring from ankylosis and root resorption, the two type of surgical defect on root surfaces were produced. 6 beagle dogs (1-2 years old) were used for study.
First type of defect was around the middle of the root facially. : U-shaped incision was made at the mucogingival line and the flap was raised on the coronal site. The periodontal tissue were completely removed in a squared area 2 2mm, 4 4mm, 6 6mm from the root surfaces. Second type of defect was at cirvical site : Incision was made at the gingival sulcus, and all of the periodontal tissue were completely removed in a square 6 6mm from the cirvical root surface, and citric acid was applicated.
The flap on the both type of defects were closed at original level. The dogs were sacrificed 2 and 3 months and it was examined a histologically. The first type of the 2 2mm squared defects were completely regenerated by the periodontal tissue. Periodontal regeneration of 4 4mm and 6 6mm squared defects were shown incompletely. Alveolar bone didn't regenerate throughout the defects. New cementum wasn't seen only at the part of a defect border. The connective tissue fibers lying parallel to the root surfaces at the no cementum site. But ankylosis and active root resorption wasn't seen at any size of defect. On the other hand, in the both type of cirvical defects (citric acid and just planed part) remoted from the influence of periodontal ligament and junctional epithelium didn't enhance new fibrous attachment and new cementum formation. And active root resorption was the predominant features of healing root surfaces facing gingival tissue. Our proposal were as follows. 1) Ankylosis and active root resorption wasn't occured in the defects removed the periodontal tissue. 2) Active resorption on the cirvical defect showed a high incidense as compared with the middle of the root surface defect.