| Project/Area Number |
01440078
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
補綴理工系歯学
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| Research Institution | Tokyo Medical and Dental University |
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Principal Investigator |
SATO Atsushige Tokyo, Faculty of Dentistry, Professor, 歯学部, 教授 (40045985)
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| Co-Investigator(Kenkyū-buntansha) |
SATO Kazuko Tokyo, Faculty of Dentistry, Research Associate, 歯学部, 助手 (50046083)
KUMEI Yasuhiro Tokyo, Faculty of Dentistry, Lecturer, 歯学部, 構師 (30161714)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥15,800,000 (Direct Cost: ¥15,800,000)
Fiscal Year 1990: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1989: ¥15,000,000 (Direct Cost: ¥15,000,000)
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| Keywords | Dental titanium alloy / Biological safety evaluation / Dissolved products in salive / Immunotoxicity / チタン合金 / 溶出試験 / 生体適合性 / インプラント材料 |
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| Research Abstract |
Dental materials are dissolved in the body fluid into trace amounts of components, which will make primary factors to bring side effects. Thus, it is important to clarify the dissolution kinetics and the toxicity of dissolved components. The metal elements in dissolution were quantitated by ICP and atomic absorption spectrophotometry. The potential hazards, particularly allergenicity and mutagenicity, of dental materials were investigated from the dose-response relationship on the dissolved products.
1. Dissolution of titanium alloy
The total amounts of titanium dissolved from 100 mg of powdered alloys, Ti6Al4V and Ti5A12.5Fe, were 1045 and 1016 ng, respectively during 14 weeks immersion in human saliva. The total amounts of aluminum dissolved from 100 mg of the alloys were 165 and 480 ng, respectively during 6 weeks immersion. The continuous trace amounts of dissolution was observed from each alloy, suggesting the possibility of genotoxicity and allergenicity.
2. Allergenicity of nickel and cadmium
The quantitation of the blood nickel and allergenicity was compared between mice of NiCl_2-water breeding and mice of subcutaneous nickel implantation.
1) The anti-nucleus antibody (ANA) was not induced by oral administration of nickel into ICR of BALB/c mice. The ANA was induced by oral administration of cadmium with a frequency of 17% of ICR mice.
2) The lymphocyte blast formation by LPS, Con-A and PHA was enhanced by oral administration of NiCl_2 into BALB/c mice. The blast formation by Con-A was increased by subcutaneous implantation of NiCl_2.
3) The relative frequency of mice spleen T cell versus B cell measured by flowcytometry was not different between the control and the nickel- or cadmium-administered mice.
4) The frequency of suppressor T cell and helper T cell was significantly decreased in the ICR mice of subcutaneous cadmium-implantation, as compared to the control.
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