| Project/Area Number |
06454539
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Conservative dentistry
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| Research Institution | Osaka University |
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Principal Investigator |
TORII Mitsuo Osaka univ., Fac.of Dent., Associate Prof., 歯学部, 助教授 (30116066)
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| Co-Investigator(Kenkyū-buntansha) |
YOKOTA Wakao Osaka univ., Fac.of Dent., Instructor, 歯学部, 助手 (00230649)
YASUNAGA Tetsuya Osaka univ., Fac.of Dent., Instructor, 歯学部, 助手 (70182342)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥6,700,000 (Direct Cost: ¥6,700,000)
Fiscal Year 1995: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1994: ¥5,900,000 (Direct Cost: ¥5,900,000)
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| Keywords | Light-cured Composites / Dentin / Cytotoxicity |
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| Research Abstract |
A new cell culture chamber in which the resin is made to lie adjacent to the cells via the dentin by culturing cells derived from the pulp on the surface of the dentin disc was devised. This new method was compared to the direct contact method with regard to the effect of irradiation time, the presence or absence of bonding agent, and pH values of the medium. In the direct contact method, cytotoxicity decreased as the irradiation time increased, while in the indirect contact method, changes in irradiation time did not influence cytotoxicity. In the former method, concomitant use of the bonding material reduced cytotoxicity, but not in the latter method. It was also demonstrated that the inclusion of the dentin prevented a decrease in the pH value of the medium. These results suggest that dentin restricts the diffusion of the monomer into the pulp. It was also clearly observed that dentin with a thickness of 1.0mm or more or dentin from patients aged 50 or over decreased cytotoxicity. Dentin immediately under the outer caries dentin also decreased cytotoxicity. However, removal of the smeared layr did not result in a change in cytotoxicity. These results demonstrate that this new cytotoxicity method using dentin enables evaluation of the cytotoxicity of light-cured composite resins in a setting closer to the clinical situation.
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