2002 Fiscal Year Final Research Report Summary
Developing and clinical application of a highly reliable dentin-bonding system.
| Project/Area Number |
12470404
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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 |
Conservative dentistry
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| Research Institution | Tokyo Medical and Dental University |
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Principal Investigator |
WATANABE Akihiko Tokyo Medical and Dental University, Institute of Biomaterials and Bioengineering, Assistant Professor, 生体材料工学研究所, 助手 (30126263)
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| Co-Investigator(Kenkyū-buntansha) |
MORIMOTO Nobuyuki Tokyo Medical and Dental University, Institute of Biomaterials and Bioengineering, Assistant Professor, 生体材料工学研究所, 助手 (00313263)
IWASAKI Yasuhiko Tokyo Medical and Dental University, Institute of Biomaterials and Bioengineering, Associate Professor, 生体材料工学研究所, 助教授 (90280990)
AKIYOSHI Kazunari Tokyo Medical and Dental University, Institute of Biomaterials and Bioengineering, Professor, 生体材料工学研究所, 教授 (90201285)
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| Project Period (FY) |
2000 – 2002
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| Keywords | Demineralized dentin / Hybrid layer / Wet bonding / Bonding mechanism / Blue laser / Scanning electron microscope / Scanning probe microscope / Transmission electron microscope |
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| Research Abstract |
After mechanical preparation of the tooth cavity with rotating instrument, the smear layer is formed on the dentin surface. Owing to the disturbance of resin adhesion to dentin, smear layer is always removedby an echant, The strong bonding to dentin can be achieved by the diffusion of resin molecules to the resulting demineralized dentin. Under some circumstances, the demineralized dentin was left surround the cavity wall after resin polymerization. The remaining demineralized dentin would be hydrolyzed and impairs the dentin bond durability greatly. For reducing the amount of residual demineralized dentin, the integrity of collagen structure should be preserved as possible. In addition, the thickness of demineralized dentin should be reduced as possible. Therefore, the milder echant should be used to leave more hydroxyapatite in the hybrid layer. The resin content in the hybrid layer is also important. It is suggested that the bond durability is attributed to the property of dentin substrate. However, few studies have reported on the effect of dentin substrate condition on bond durability. It is well accepted that the diffused resin could be polymerized and hybridized in the demineralized dentin layer. In this study, a reliable light-curing dentin bonding agent was established according to this concept. In wet bonding technique, the diffusion ability of resin to demineralized dentin can be increased by repeated priming procedure. The resin content was increased in the hybrid layer. A high quality adhesive layer was established. EDTA is known to remove the smear layer and demineralized the underneath sound dentin (thickness : 1μm〜2μm). Monomer in this layer is polymerized and hybridized with dentin. A blue laser with the wave-length of 473 nm, can be used to cure the resin monomer in the demineralized dentin layer. A reliable curing system for curing commercial dentin bonding agents was established.
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