| Project/Area Number |
09672089
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
矯正・小児・社会系歯学
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
YAWAKA Yasutaka Hokkaido Univ., School of Dent., Inst., 歯学部, 助手 (60230603)
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| Co-Investigator(Kenkyū-buntansha) |
KAGA Masayuki Hokkaido Univ., School of Dent., Asso. Pro., 歯学部, 助教授 (70125300)
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| Project Period (FY) |
1997 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1999: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1998: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1997: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | human deciduous teeth / apical periodontitis / pathologlcal root resorption / cementum deposition / cultured osteoclasts / tartrate-resistant acid phosphatase (TRAP) / enbedding / histologicai observation / 走査型電子顕微鏡 / 酒石産耐性酸フォスファターゼ(TRAP) / 酒石酸耐性酸フォスファターゼ活性反応 / 吸収窩 / 破歯細胞 / 光学顕微鏡 / 透過型電子顕微鏡 |
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| Research Abstract |
The purpose of this study was to examine a different root resorption process on the root dentin with apical periodontitis or on sound root dentin.
1. The region of the root apex with severe apical periodontitis in human deciduous teeth was observed by light and transmission electron microscopy. Root dentin and original cementum had a severe irregular caved surface due to pathological root resorption. Cementum had partial!y deposited on the caved dentin and original cementum surfaces. The structure of deposited cementum was very different from that of the original cementum. It was thought that partial repair mechanisms such as cementum deposition are affected by the surrounding environment of the root.
2. Root dentin slices were prepared from human deciduous teeth with apical periodontitis (group p) or sound human deciduous teeth (group n, control). Cell suspension of bone marrow from the femur of mice in α MEM was seeded on the dentin slices and incubated. After incubation, specimens wer
… More
e removed and fixed, and then observed for tartrate-resistant acid phosphatase (TRAP) activity. The number of TRAP-positive cells on the dentin was calculated by light microscopic observation. TRAP-positive cells were observed in all dentin slices. There were no significant differences between group p and group n on the number of TRAP-positive cells by Mann-Whitney test. The results suggested that root dentin with apical periodontitis was resorbed by cultured osteoclasts It was thought that enviromental factors in root circumferences had a greater effect than does the condition of root dentin on pathological root resorption.
3. The root dentin slices of group p and group n were embedded in rats subcutaneous tissue. The dentin slices of both groups were surrounded by fibrous connective tissue are inflammatory cells and partially resorbed by multinuclear giant cells. However, the resorption was slight. There were no differences between the both groups on the condition of the dentin slices. It was thought that the condition of root dentin had few effect on pathological root resorption.
Therefore, it was suggested that enviromental factors in root circumferences had a great effect on patholagical root resorption. Less
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