Goulart Marcelo, Borges Veleda Barbara, Damin Deisi, Bovi Ambrosano Glaucia Maria, Coelho de Souza Fabio Herrmann, Erhardt Maria Carolina Guilherme
Int J Esthet Dent. 2018;13(1):86-97.
The aim of this study was to evaluate the effect of preheating composite resins used as luting agents for indirect restorations on microtensile bond strength (µTBS) and adhesive interfaces.
Fifty sound extracted third molars were used. Ten experimental groups were formed with three different luting agents: one resin cement (RelyX ARC) and two composite resins (Venus and Z250 XT). The composite resins were tested both at room temperature and when preheated to 64°C. Restoration depth was tested using 2 or 4 mm-height indirect composite resin restorations, previously made on cylindrical molds. Adhesive and luting procedures were done under simulated pulpal pressure. After luting, the teeth were sectioned into beams with a cross-sectional area of 1 mm2 at the bonded interface, and tested in tension at 0.5 mm/min. The characteristics of the adhesive interfaces were observed under scanning electron microscopy (SEM). The µTBS data were analyzed using ANOVA and the Tukey test (α = 0.05).
When luting 2 mm restorations, the composite resin Z250 XT, preheated or at room temperature, achieved significantly higher µTBS than did RelyX ARC. At this depth, Venus did not differ from the resin cement, and with the 4 mm restorations, only preheated Venus presented significantly higher µTBS than RelyX ARC. Preheating the composite resin resulted in thinner luting interfaces, with a more intimate interaction between luting agent and adhesive layer.
Preheating composite resin for luting procedures may not improve µTBS, although it could be used to reduce material viscosity and improve restoration setting.
本研究旨在评估用作间接修复体粘结剂的复合树脂预热对微拉伸粘结强度（µTBS）和粘结界面的影响。
使用50颗完整拔除的第三磨牙。用三种不同的粘结剂形成10个实验组：一种树脂水门汀（RelyX ARC）和两种复合树脂（Venus和Z250 XT）。复合树脂在室温下以及预热至64°C时进行测试。使用先前在圆柱形模具上制作的2或4毫米高的间接复合树脂修复体测试修复深度。粘结和粘结程序在模拟牙髓压力下进行。粘结后，将牙齿在粘结界面处切成横截面积为1平方毫米的梁，并以0.5毫米/分钟的速度进行拉伸测试。在扫描电子显微镜（SEM）下观察粘结界面的特征。使用方差分析和Tukey检验（α = 0.05）分析µTBS数据。
粘结2毫米修复体时，预热或室温下的复合树脂Z250 XT的µTBS显著高于RelyX ARC。在此深度，Venus与树脂水门汀无差异，对于4毫米修复体，只有预热的Venus的µTBS显著高于RelyX ARC。复合树脂预热导致粘结界面更薄，粘结剂与粘结层之间的相互作用更紧密。
粘结程序中预热复合树脂可能不会提高µTBS，尽管它可用于降低材料粘度并改善修复体固化。
