| Project/Area Number |
14571848
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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 | OKAYAMA UNIVERSITY |
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Principal Investigator |
YOSHIDA Yasuhiro Okayama University, Graduate School of Medicine and Dentistry, Associate Professor, 大学院・医歯学総合研究科, 助教授 (90281162)
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| Co-Investigator(Kenkyū-buntansha) |
OKAZAKI Masayuki Hiroshima University, Graduate School of Biomedical Sciences, Professor, 大学院・医歯薬学総合研究科, 教授 (30107073)
SUZUKI Kazuomi Okayama University, Graduate School of Medicine and Dentistry, Professor, 大学院・医歯学総合研究科, 教授 (30050058)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥4,000,000 (Direct Cost: ¥4,000,000)
Fiscal Year 2003: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2002: ¥2,900,000 (Direct Cost: ¥2,900,000)
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| Keywords | adhesion / self-etch / primer / functional monomer / TEM / XPS / dentin / apatite |
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| Research Abstract |
Commonly, acidic monomers in self-etch primers/adhesives are esters originating from the reaction of a bivalent alcohol with methacrylic acid and phosphoric/carboxylic acid derivatives. Each self-etch adhesive contains its specific functional monomer that to a large extent determines its actual adhesive performance. Thus far however, the interaction of functional monomers, with dental tissues has seldom been characterized using chemical analytical techniques. We therefore characterized the adhesive interaction of three functional monomers chemically with synthetic hydroxyapatite using X-ray Photoelectron Spectroscopy and Atomic Absorption Spectrophotometry, and ultra-morphologically with dentin using Transmission Electron Microscopy. High-resolution microscopic analysis showed that all three self-etch adhesives hybridized dentin, indicating that their bonding mechanism at least in part depended on micro-mechanical interlocking of resin into a micro-porous surface. In contrast to etch-and-rinse adhesives that involve phosphoric-acid etching, the self-etch adhesives only partially demineralized dentin, leaving hydroxyapatite partially attached to collagen. Knowing that hydroxyapatite remains available for interaction, the main objective of this study was to characterize any potential chemical interaction the functional monomers may have with this residual hydroxyapatite. The monomer 10-methacryloxydecyl dihydrogen phosphate (10-MDP) readily adhered to hydroxyapatite. This bond appeared very stable, as confirmed by the low dissolution rate of its calcium salt in water. The bonding potential of 4-methacryloxyethyl trimellitic acid (4-MET) was substantially lower. The monomer 2-methacryloxyethyl phenyl hydrogen phosphate (phenyl-P) and its bond to hydroxyapatite appeared not very hydrolytically stable. Besides self-etching dentin, specific functional, monomers have an additional chemical bonding efficacy that is expected to contribute to adhesive performance.
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