| Project/Area Number |
15592045
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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 |
補綴理工系歯学
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| Research Institution | Tokyo Medical and Dental University |
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Principal Investigator |
KODAMA Yoshinori Tokyo Medical and Dental University, Institute of Biomaterials and Bioengineering, Associate Professor, 生体材料工学研究所, 助教授 (00092403)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2004: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2003: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | Bis-GMA / Bisphenol A / Radical |
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| Research Abstract |
The aim of the present investigation was to confirm the safety of Bis-GMA monomer by removing bisphenol A (BPA) from the monomer paying attention of the radical scavenging ability of BPA.
1.Radical scavenging reaction with poly(methyl methacrylate) (PMMA)
The amount of radical remaining in PMMA was related to its glass transition temperature and the amount was adjustable with heating. Copolymers of methacrylate monomer with MMA was prepared to enhance the solubility of polymers in Bis-GMA. The radical scavenging reaction with these copolymers could not remove BPA completely.
2.Radical scavenging reaction with precursor of radical
Taking into account the solubility in Bis-GMA, low molecular weight precursors of radical, initiator system of visible light and heat polymerization, were used. Radical forming system by heat was not able to remove BPA successfully resulting in the heat polymerization of Bis-GMA. On the other hand, radical forming system by visible light irradiation was able to control both radical scavenging reaction and polymerization by adjusting the concentration of precursor of radical and the intensity of light irradiation.
3.Removal of BPA by chromatography
The main monomer component of Bis-GMA was purified by silica gel column chromatography treatment of commercial Bis-GMA product to examine the chemical reactivity of pure Bis-GMA. The addition of a precursor of radical, copolymer or initiator into pure Bis-GMA did not produce BPA, which indicated that dental products containing Bis-GMA never exert a harmful effect such as release of BPA once BPA was removed. It was also suggested in the process of the purification of Bis-GMA that BPA can be removed by adsorbents.
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