| Project/Area Number |
18592095
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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 |
Conservative dentistry
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| Research Institution | Kyushu Dental College |
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Principal Investigator |
CHEN Ker-Kong Kyushu Dental College, Dentistry, Assistant Professor (20207327)
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| Co-Investigator(Kenkyū-buntansha) |
TAJIMA Kiyoshi Kyushu Dental College, Assistant Professor (60155075)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥1,880,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥180,000)
Fiscal Year 2007: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2006: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | Tooth / Wedge-shaped defect / Finite element method / Cervical region / Abfraction / Stress Distribution / Model construction / Occlusion / アブフラクション / 応力解析 / ひずみ / 数値モデル / モデル妥当性 |
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| Research Abstract |
Abfraction is known to have great deal with the formation of wedge-shaped defect (WSD). The finite element method (FEM) studies have confirmed that the stress concentration area during loading is consistent with the frequently observed WSD region. However, those FEM results were obtained by using 2-D FE model instead of 3-D FE model because of the difficulties in constructing the complex anatomical morphology and occlusal surface. This study used 3-D FE model to investigate the stress distribution by focusing on the cervical region under various occlusal loading and to find out the resolution for WSD by FEM. The 3-D FE model was constructed by using micro CT images of maxillary premolar and its validity was also examined. Furthermore, the distribution of principal stress occurred at cervical region enamel from mesial, buccal to distal surfaces (cemento-enamel junction) was measured under loading (loading points: tip of lingual cusp, mesial marginal ridge and distal marginal ridge) in a direction parallel to tooth axis or in an inclination of 15, 30, 45 degrees to tooth axis. The results were as follows.
1) 3-D FE model was successfully reconstructed to reveal the tooth anatomical morphology by the use of micro CT images.
2) The analytical value of stress obtained from 3-D FE model was consistent with the value detected by strain gauge that attached on tooth cervical region. It is indicated that the 3-D FE model is suitable to replace tooth for further FEM investigation.
3) The principal tensile stress occurred around the cemento-enamel junction became larger with the increasing inclination of loading force. However, the tensile stress can be relieved by adjusting the number of loading points or loading ratio in those loading points. It is suggested that the appropriate contact patterns can not only relieve but also inhibit the formation of WSD.
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