Project/Area Number |
01480447
|
Research Category |
Grant-in-Aid for General Scientific Research (B)
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Allocation Type | Single-year Grants |
Research Field |
補綴理工系歯学
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Research Institution | Kyoto University |
Principal Investigator |
TANI Yoshiaki Kyoto University, Research Center for Biomedical Engineering, Professor, 生体医療工学研究センター・生体材料学研究部門, 教授 (90026881)
|
Co-Investigator(Kenkyū-buntansha) |
TOGAYA Toshihiro Kyoto University, Research Center for Biomedical Engineering, Assistant Professo, 生体医療工学研究センター・生体工学研究部門, 助手 (50127106)
TSUTSUMI Sadami Kyoto University, Research Center for Biomedical Engineering, Associate Professo, 生体医療工学研究センター・人工臓器学研究部門, 助教授 (00028739)
|
Project Period (FY) |
1989 – 1990
|
Project Status |
Completed (Fiscal Year 1990)
|
Budget Amount *help |
¥6,700,000 (Direct Cost: ¥6,700,000)
Fiscal Year 1990: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1989: ¥5,100,000 (Direct Cost: ¥5,100,000)
|
Keywords | Laser Irradiation / Dentin / Smear Layer / Treatment of Dentin / Bonding / Pretreatment for Bonding / レーザー / 象牙質前処理 |
Research Abstract |
Various adhesion promoters have been developed and are in wide use. However, the treatment of the dentin as an adherent is a more important issue. A variety of procedures have been proposed for the treatment of the smear layer produced by cutting the dentin surface ; but, in view of dentin permeability and protection of the dental pulp, any method of pretreatment that is likely to cause decalcification of the peritubular dentin, and opening and expansion of the dentinal tubules, should be avoided. We investigated the possibility of treating the smear layer by laser irradiation. The surface of the smear layer was irradiated with a laser, and the changes were observed under a scanning electron microscope. A CO_2 gas laser (Satelec Lasersat CO_2) was used in defocus. The results showed that the laser induced changes in the smear layer. The smear layer on the intertubular dentin was satisfactorily treated, with the tubular orifices closed at the energy densities of 30-50 J/cm^2. Next, we determined the temperature rise in the pulp by CO_2 laser irradiation. The temperature rise by laser irradiation at the energy density of 60 J/cm^2 in defocus showed below 6^゚C if the thickness of the remaining dentin to the pulp from the cavity floor was more thicker than 1 mm.
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