| Project/Area Number |
06454534
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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 | HOKKAIDO UNIVERSITY |
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Principal Investigator |
TANAKA Toru Hokkaido Univ., School of Dentistry, Instructor, 歯学部, 助手 (90179771)
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| Co-Investigator(Kenkyū-buntansha) |
UNO Shigeru Hokkaido Univ., Dental Hospital, Lecturer, 歯学部・附属病院, 講師 (00168733)
NOZAWA Toshihiko Hokkaido Univ., Dental Hospital, Instructor, 歯学部・附属病院, 助手 (20261315)
YOSHIMURA Manabu Hokkaido Univ., School of Dentistry, Instructor, 歯学部, 助手 (20191645)
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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 |
¥4,900,000 (Direct Cost: ¥4,900,000)
Fiscal Year 1995: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1994: ¥3,800,000 (Direct Cost: ¥3,800,000)
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| Keywords | Reduced rate / Composite resin / Uncured monomer / Marginal adaptation / Knoop hardness / 機械的強度 / 内部硬さ |
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| Research Abstract |
The effects of the polymerization of the resin composite at the reduced rate were investigated on marginal adaptation in the dentinal cavities and diametral tensile strength. Besides the degree of cure was evaluated by the internal hardness and elution of uncured monomers on. A light source which enabled to change the light intensity was intended for the aim.
To summarize :
1.Polymerization at 9 V for 120 seconds resulted in a good marginal adaptation in the dentinal cavities restored with three light-cured resin composites, Palfique Estelite, Z-100, Lite-fil II A.
2.The specimens polymerized at 9 V for 120 seconds showed a desirable hardness since this irradiation condition produced comparative Knoop hardness to the ordinal condition, 12 V for 60, used clinically.
3.The diametral tensile strengths of the specimens polymerized at 9 V for 120 seconds did not differed to those cured at 12 V for 60 seconds.
4.Uncured monomers of HEMA,TEGDMA and Bis-GMA were eluted from the irradiated resin specimens, Lite-fil II A.
5.When the specimens were polymerized at the 8 V,the uncured monomers released decreased with an increase in irradiation time.
6.For TEGDMA and Bis-GMA the eluted values did not differ whether polymerization was performed at the reduced rate, 8V,or at the ordinal voltage, 12 V.
7.Polymerization at the reduced rate possibly produces a resin composite restoration well adapted with desirable mechanical properties.
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