Lara Lucas, Rocha Mateus Garcia, Menezes Livia Rodrigues, Correr Américo Bortolazzo, Sinhoreti Mario Alexandre Coelho, Oliveira Dayane
Gen Dent. 2022 May-Jun;70(3):60-64.
The objective of this in vitro study was to evaluate the mechanical properties of different bulk-fill composite resins with or without a final layer of conventional composite resin. The null hypothesis was that the mechanical properties of the material would not change regardless of the addition of a layer of conventional composite. Bar-shaped specimens (25 × 2 × 2 mm) were made from 4 different bulk-fill composites (Filtek One Bulk Fill, Filtek Bulk Fill Flowable, Tetric EvoCeram Bulk Fill, and Tetric EvoCeram Bulk Fill Flow) with or without a final layer of a conventional composite of the same brand (Filtek Supreme for the Filtek materials and Tetric EvoCeram for the Tetric materials). Each specimen was light cured at 2 equidistant points using a multiwave curing light with a power output of 20 J/cm. All of the specimens were subjected to a 3-point bending test in a universal testing machine at a crosshead speed of 0.75 ± 0.25 mm/min and a load rate of 50 ± 16 N/min, and the flexural strength and elastic modulus were calculated. The mean flexural strength and elastic modulus values were analyzed using 1-way analysis of variance, and then the Tukey test was applied for multiple comparisons between groups (α = 0.05). When a final layer of a conventional composite of the same brand was added, the mean flexural strength of the Tetric groups slightly decreased, while that of the Filtek groups did not change. Application of a final layer of conventional composite resulted in a slight increase in the mean elastic modulus of the Filtek groups and either no change or a slight decrease in the Tetric groups. The addition of a final layer of conventional composite resin did not seem to improve the mechanical properties of any of the tested bulk-fill materials. The addition of a final layer of conventional composite resin can affect the mechanical properties of bulk-fill materials; however, it seems these effects are dependent on the type of conventional composite resin used for the final layer.
本体外研究的目的是评估不同的大块充填复合树脂在有无传统复合树脂终末层情况下的力学性能。无效假设是无论是否添加一层传统复合树脂，材料的力学性能都不会改变。棒状试件（25×2×2mm）由4种不同的大块充填复合材料制成（Filtek One Bulk Fill、Filtek Bulk Fill Flowable、Tetric EvoCeram Bulk Fill和Tetric EvoCeram Bulk Fill Flow），有无同一品牌的传统复合树脂终末层（Filtek材料用Filtek Supreme，Tetric材料用Tetric EvoCeram）。每个试件使用功率输出为20J/cm的多波固化灯在2个等距点进行光固化。所有试件在万能试验机上以0.75±0.25mm/min的十字头速度和50±16N/min的加载速率进行三点弯曲试验，并计算弯曲强度和弹性模量。使用单因素方差分析对平均弯曲强度和弹性模量值进行分析，然后应用Tukey检验进行组间多重比较（α = 0.05）。当添加同一品牌的传统复合树脂终末层时，Tetric组的平均弯曲强度略有下降，而Filtek组则没有变化。应用传统复合树脂终末层导致Filtek组的平均弹性模量略有增加，Tetric组则无变化或略有下降。添加传统复合树脂终末层似乎并未改善任何测试的大块充填材料的力学性能。添加传统复合树脂终末层会影响大块充填材料的力学性能；然而，这些影响似乎取决于用于终末层的传统复合树脂的类型。
