| Project/Area Number |
61570960
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
外科・放射線系歯学
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| Research Institution | Nihon Univeraity |
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Principal Investigator |
KOJI HASHIMOtTo Nihon unversity School of Dentistry, Lecturer, 歯学部, 講師 (90139197)
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| Co-Investigator(Kenkyū-buntansha) |
KEIICHI TOGAWA Nihon Unversity School of Dentistry, Assistant, 歯学部, 助手 (70180122)
舘野 誠 日本大学, 歯学部, 助手 (70139202)
MAKOTO TATENO Nihon Uversity School of Dentistry, Assistant, 歯学部, 助手 (80151702)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1987: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1986: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | Nationwide Surcey / Dental Radiology / Populaton Dose / 集団実効線量当量 / リスク / 歯科医療 / X線撮影 / 職業別電話帳 |
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| Research Abstract |
We carried a nation wide survey in the frequency of dental radiography and the exposure factors by the cooperation with dental clinics,dental departments of general hospitals,and dental colleges of whole Japan in 1987. The total number of dental rediography in Japan were estimated and the estimation of population dose was performed.
The results were as follows: 1.The total number of intra-oral radiography taken in whole Japan was estimated about 9100x104 and panoramic rediography was about 1140x104 in 1987. 2.Almost every dental clinics had taken the dental x-rays under the condition of 60kV and 10mA. 3.More than 85% of the dental x-ray units which were surveyed had open-end cylindrical cones. And the effective dose related to the malignant significant dose (MSD) and the effective dose equivalent recommended by the International Commission on Radiological protection (ICRP) were calculated using the corresponded weighting factors and the organ tissus doses from the phantom mesturement.
The resultant annual population doses per person were 98 ngy from intra-oral radiography (IOR) and 6.4 nGy from orthopantomography (OPR) for GSD, 8.5 uGy from IOR,and 2.3 ugy from OPR for CMD,7,5 uGy from IOR and 2.1 uGy from OPR for LSD,and 7.1 uGy from IOR and 1.3 uGy from OPR for MSD,respectively.The population risks of Japanese were estimated to be 0.17 for the genetic effects,2.3 for the fatal leukemia and 16.7 for fatal malignant diseases. The annual collective dose equivalents were about 2370 man SV from dental intra-oral radiography and 470 man SC from orthopantomography,with a total of 2840 man SV.
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