| Project/Area Number |
08680919
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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 |
Biomedical engineering/Biological material science
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| Research Institution | Hokkaido University |
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Principal Investigator |
YAMAMOTO Katsuyuki Hokkaido Univ., Graduate School of Eng., Professor, 大学院・工学研究科, 教授 (10088867)
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| Co-Investigator(Kenkyū-buntansha) |
MORIKAWA Hajime Asahikawa National College of Technology, Instructor, 助手 (20239635)
KUDO Nobuki Hokkaido Univ., Graduate School of Eng., Instructor, 大学院・工学研究科, 助手 (30271638)
SATOH Yoshiaki Hokkaido Univ., School of Dent., Instructor, 歯学部, 助手 (00250465)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1997: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1996: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | biomechanics / bone remodeling / orthodontics / alveolar bone / osteoclast / periodontal ligament / elastic properties / Young's modulus |
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| Research Abstract |
The purpose of this study is to clarify the causal relationship between mechanical stress and alveolar bone remodeling during orthodontic treatment. Material constants of the periodontal ligament (PDL) are indispensable parameters for stress analysis of a tooth and the surrounding tissues. However, few experimentally determined values have been reported. In this study, we developed a small compressive and tensile test machine in order to determine the material constants of the PDL.In tension tests, stress-strain curves did not significantly depend on strain rates. In contrast, compressive tests showed great dependence of the curves on strain rates. Tensile and compressive tangent moduli of the PDL were 0.37(]SY.+-。[)0.11 and 0.079(]SY.+-。[)0.017 MPa, respectively, under quasi-static conditions. Poisson's ratio of a compressed PDL specimen was significantly lower than that of a tensile specimen. Based on these material constants, we couducted stress analyzes using specimen-specific 2-D finite-element models which were constructed from morphological structure of tissue sections taken from a cat canine subjected to experimental orthodontic treatment The results clearly demonstrated that there is a close correlation between the appearance of osteoclasts and the principal stress distribution in the PDL.Most osteoclasts appeared at the specific sites where the compressive stress was about 4 kPa.
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