Grant-in-Aid for Scientific Research (B).
|Research Institution||TOKYO DENTAL COLLEGE|
SHIMONO Masaki Tokyo Dental College, Dept. of Dentistry, Professor, 歯学部, 教授 (00085771)
SUGAYA Tsutomu Hokkaido University, Dept. of Dentistry, Lecturer, 歯学部・付属病院, 講師 (10211301)
HASHIMOTO Sadamitsu Tokyo Dental College, Dept. of Dentistry, Lecturer, 歯学部, 講師 (10201708)
TAKATA Takashi Hiroshima University, Dept. of Dentistry, Assoc. Professor, 歯学部, 助教授 (10154783)
MAEDA Takeyasu Niiigata University, Dept. of Dentistry, Professor, 歯学部, 教授 (40183941)
YAMADA Sstoru Tokyo Dental College, Dept. of Dentistry, Professor, 歯学部, 教授 (20103351)
|Project Fiscal Year
1998 – 1999
Completed(Fiscal Year 1999)
|Budget Amount *help
¥12,600,000 (Direct Cost : ¥12,600,000)
Fiscal Year 1999 : ¥3,800,000 (Direct Cost : ¥3,800,000)
Fiscal Year 1998 : ¥8,800,000 (Direct Cost : ¥8,800,000)
|Keywords||periodontal ligament / root surface treatment / connective tissue attachment / epithelial attachment / cell proliferation / cell differentiation / reattachment / enamel matrix protein / 歯根膜 / 根面処理 / 再付着 / 結合組織性付着 / 上皮性付着 / 細胞増殖 / 細胞分化 / エナメル基質蛋白|
The aim of this comprehensive study is development of new root surface treatment method to acquire the connective tissue attachment, and it's clinical application in which after periodontal surgery. In this project, relationship between the dynamics of periodontal ligament cells and the new root surface treatment was clarified by various methods. Followings results were obtained.
(1) The mechanism of cell proliferation and differentiation in the periodontal ligament (Takata).
(2) The involvement of the nerve in the regeneration process of the periodontal tissue (Maeda).
(3) The mechanism of regeneration and homeostasis of the periodontal tissue (Shimono).
(4) The correlation between epithelial attachment and connective tissue attachment (Hashimoto).
(5) The regenerative change of the periodontal tissue by Growth factor application (Sugaya).
(6) The acquisition of connective tissue attachment by the enamel substrate protein (Yamada).
(7) The involvement of the microcirculation in the reattachm
ent of the periodontal tissue (Sekiguchi).
Proliferation activities were higher in the shallower subpopulations near the PDL surface. On the other hand, activities of alkaline phosphatase (ALP) and calcification were higher in the deeper subpopulations close to the root surface. Interestingly, the PDL subpopulation on the root surface showed the high activities both in ALP and proliferation. The experimental model established here could be an excellent tool for the discussion of new regenerative therapies using growth factors. The terminal Schwann cells migrated into tooth-related part, where the Ruffini endings were rarely observed in intact ligament, during degeneration process. Prior to regeneration of periodontal Ruffini endings, they moved to alveolus-related part. These data suggested that terminal Schwann cells play important roles in regeneration of periodontal Ruffini endings. The importance of Malassez epithelial rest or remnant in the maintenance of the periodontal ligament was indicated. In the internal lamina of the long-junctional epithelium, Integrin and Laminin-5 were indicated, and it suggested to be important for epithelial attachment. A significant increase of protein concentration and cell number in rhPDGF-BB groups and a significant increase of ALP activity in rhBMP-2 groups was observed. Thus, rhPDGF-BB and rhBMP-2 application to EDTA demineralized dentin surfaces promote the periodontal ligament cell responses respectively which ulimately would enhance periodontal regeneration. The application of the citric acid on the dentin can act as positive factor for cementum formation. The superficially decalcified dentin matrix treated with citric acid has the ability toinduce cementogenesis. Less