1993 Fiscal Year Final Research Report Summary
Development of the composite resin with less amount of the shrinkage
| Project/Area Number |
04807139
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
補綴理工系歯学
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| Research Institution | Nihon University |
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Principal Investigator |
NEMOTO Kimiya Nihon University, School, Professor of Dentistry at Matsudo, 松戸歯学部, 教授 (00050039)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Composite resin / Shrinkage / Volumetric shrinkage / Linear shrinkage / Curing rate / Filler / Filler content / Shrinkage stress |
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| Research Abstract |
In order to obtain information concerning which parameters control the shrinkage of the experimental filled resin during hardening, the volumetric shrinkage and the linear shrinkage of the experimental filled resin were investigated. The correlation between the shrinkage stress and these datas was discussed.
The volumetric shrinkage of the filled resin is dependent on the filler content. Contrary, the linear shrinkage is not 1/3 of the volumetric shrinkage even if the filler content was increased. However, when the length become shorter less than 5 mm, the linear shrinkage become larger and it's value become above 3 times, and approximates to 1/3 of the volumetric shrinkage. The magnitude of the linear shrinkage is different by the size and type of the cavity.
The shrinkage stress of the filled resin become larger until the filler content is 60 % even if the volumetric shrinkage become smaller. The volumetric shrinkage of the synthesized di-methacrylate monomer which the cyclopolimerization is possible is pretty similar to that of commercial dimethacrylate monomers.
Next, the effect of the lining cement on the shrinkage stress of the filled resin was investigated. The shrinkage stress become 1/2 of that obtained without a lining cement. The application of the lining cement, 0.5-1.5mm reduces the shrinkage stress.
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