| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2001: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2000: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1999: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Research Abstract |
Marginal adaptation of eight commercially available resin composites, Clearfil APX, Estelite, Estio LC, Litefil IIA, Prodigy, Progress, Silux Plus and Z-100, were detemiined by measurement of the contraction gap width in a cylindrical dentin cavity. The cavity walls were treated with the experimental dentin bonding system consisting of 05M EDTA, 35% glyceryl mono-methacrylate solution and Clearfil Photo Bond. Three composites, Clearfil APX, Estelite and Silux Plus, prevented the contraction gap formation completely. There was not significantly deference (p>0.O5) between the gap width and tensile bond strength to flat dentin surface of the eight composites.
The thixoiropy indexes [TI] of the eight composite pastes depending on a lime were detemiined by a cone and plate viscometry sensor system mounted in a Viscotester VT550.The composite pastes were stored, in 24+1C at least for 24 hours, and then transferred on the thermostatic plate senser at 37+1C. The TI at 10.68 s-1 of a shear rate correlated significantly (r2=0.822) with the measured gap width. Furthermore the yield strengths and thixotropy depending on a rotalive velocity of the eight composites were measured by a truncated cone and plate viscometry senser system mounted in a Rheosiress RS75.Condition of the composite pastes and plate senser were controlled as same as measuring of the TI. The TI of the eight composites correlated significantly (r2=0.757) with the measured gap width. The rheological properties of the composite pastes may predict the marginal adaptation of the polymerized composites in dentin cavity.
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