Effect of Rheological Properties of Resin Composite Pastes on Marginal Adaptation of the Restoration in Dentin Cavity

通过测量圆柱形牙本质洞内收缩缝隙宽度，测定了8种市售树脂复合体：Clearfi APX、Estite、Estio LC、Litefi IIA、Prodigy、Progress、Silux Plus和Z-100的边缘适合性。使用由05M EDTA、35%甲基丙烯酸甘油酯溶液和Clearfe Photo Bond组成的实验性牙本质粘结系统处理洞壁。三种复合材料Clearfi APX、ESTELITE和SILUX Plus完全防止了收缩间隙的形成。8种复合糊剂的间隙宽度和与牙本质平坦表面的拉伸粘结强度之间没有显著差异(p&gt；0.O5)。8种复合糊剂对石灰的触变指数[TI]由安装在粘度计VT550中的锥板式粘度传感器系统测定。复合糊剂在24+1℃下储存至少24小时，然后在37+1℃下转移到恒温平板传感器上。在切变率为10.68 S~(-1)时，TI值与林隙宽度呈显著正相关(R2=0.822)。此外，通过安装在Rheosiress RS75上的截锥板粘度计传感系统测量了8种复合材料的屈服强度和随转速变化的触变性。复合糊和板式传感器的条件控制与TI的测量相同。8种复合材料的TI值与测量的缝隙宽度显著相关(R2=0.757)。复合糊体的流变性可以预测聚合体在牙本质洞中的边缘适合性。

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.