两种充填方式对不同光固化复合树脂充填体内孔隙的影响

目的 探讨光固化复合树脂的稠度及充填方式对充填体内孔隙的影响,以期为复合树脂的临床应用提供参考.方法 6位操作者将3种复合树脂(树脂A:Prodigy;树脂B:Tetric EvoCeram;树脂C:Tetric Ceram HB)以器械充填和注射充填的方式充填入模拟I类洞中,将充填体纵向片切成0.5 mm厚的切片,测定切片内孔隙数量;并测试未进行充填的复合树脂内的固有孔隙数量.结果 未充填的复合树脂内固有孔隙数量极少(≤5个);稠度居中的树脂B的孔隙数量器械充填和注射充填分别为(1137.1±365.0)和(566.1±206.4)个]远多于稠度最大的树脂C分别为(193.1±35.8)和(156.3±33.0)个]和稠度最小的树脂A分别为(241.0±116.1)和(195.8±28.7)个,P<0.05).树脂B器械充填的孔隙数量明显多于注射充填(P<0.05),而树脂A和C两种充填方式的孔隙数量差异均无统计学意义(P>0.05).结论 复合树脂充填体内的孔隙基本是在充填过程中形成的,孔隙数量与复合树脂稠度无线性关系;并非所有复合树脂用注射充填均能显著减少充填体内孔隙数量.

Evaluation of porosity in the restorations of light-cured resin composite

Objective To investigate the influenee of the consistency of resin composite and insertion techniques on the homogeneity of the Class I restorations.Methods Standardized Class I cavities were prepared in polymethyl methyacrylate(PMMA) blocks and restored with three resin composites (Prodigy,Tetric EvoCeram and Tetric Ceram HB)using either a packing or an injection technique by six operators.Then the restorations were sectioned longitudinally and inspected for the presence of porosities and voids with microscope.The consistence of the three resins was tested using an area method.Results There is little porosity in original resin.After insertion,large numbers of porosities were observed in restorations,with Tetric EvoCeram presented much more porosities(1137.1±365.0 for packing and 566.1 ±206.4 for injection)than Prodigy(241.0±116.1,195.8±28.7)and Tetric Ceram HB(193.1±35.8,156.3±33.0).Tetric Ceram HB showed the highest consistency,followed by Tetric EvoCeram and Prodigy.No linear correlation was found between the consistency of the composite and the porosity of their restorations.For Tetric EvoCeram.the restorations inserted with packing showed significant more porosity than that with injection.Contrastively,the restorations of Prodigy or Tetric Ceram HB presented no apparent difference for the two filling techniques.Conclusions The porosity in restoration was primarily created during the insertion.There was no linear correlation between the consistency of the composite and the porosity of their restorations.The porosity of composite resin is material-brand dependent.The influence of filling techniques on the porosity of restoration is depending on the composite used.