| Project/Area Number |
11470413
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
補綴理工系歯学
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| Research Institution | Kanazawa University |
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Principal Investigator |
UEDA Takashi Kanazawa University Engineering Professor, 工学部, 教授 (60115996)
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| Co-Investigator(Kenkyū-buntansha) |
MAHFUZ Alfuda Assistant, 工学部, 助手 (90313692)
YAMADA Keiji Assistant, 工学部, 助手 (50242532)
HOSOKAWA Akira Assistant Professor, 工学部, 助教授 (40199493)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥11,300,000 (Direct Cost: ¥11,300,000)
Fiscal Year 2000: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1999: ¥10,400,000 (Direct Cost: ¥10,400,000)
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| Keywords | DENTAL TREATMENT / YAG LASER / TEETH / CAVITY / TEMPERATURE MEASUREMENT / TWO-COLOR PYROMETER / FINITE ELEMENT METHOD / 赤外線 / Z色温度計 |
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| Research Abstract |
The flush temperature of a dental hard tissue irradiated with pulsed YAG laser is measured using a two-color pyrometer with an optical fiber. This pyrometer consists of a chalcogenide optical fiber and a laminated infrared detector.
The influence of the laser power on the temperature of the dental tissue is investigated, and the relation between the laser power and the removal volume of the dental tissue is obtained. In order to examine the thermal damage on the dental tissue, hardness and bending strength of the tissue are measured after being heated electrically at various temperature. FEM thermal analysis is conducted to estimate the temperature distribution in a teeth and to discuss the influence of heat flux on the dental pulp. The result obtained are as follows. The appcarance of the tissue begins to change at about 200℃ and its hardness decreases with the increase of temperature. Its bending strength starts to decrease at about 50℃. Only the carious tissue can be removed from the cavity due to the large difference of energy absorptivity between the tissue and the carious one. It is possible to protect the dental pulp from thermal damage, because the temperature gradient in the teeth is very steep due to the small thermal conductivity of the dental tissue.
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