Department of Restorative Dentistry, School of Dentistry, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil.
J Prosthodont. 2012 Feb;21(2):101-11. doi: 10.1111/j.1532-849X.2011.00794.x. Epub 2011 Nov 1.
To evaluate the microtensile bond strength and interfacial micromorphology of indirect composite restorations to dentin using three commercial resin cements after 24 hours and 30 days of water storage.
The medium dentin of third human molars was exposed (N = 30, n = 10 per group). Three commercial resin cements were used to cement indirect resin composite restorations to dentin: the auto-cured C&B Cement/All Bond 2, the dual-cured RelyX ARC/Adper Single Bond 2, and the self-adhesive dual-cured RelyX Unicem. Teeth were sectioned after water storage at 37°C (24 hours and 30 days) to obtain beams with a bonded area of 0.8 mm(2) . The specimens were tested in a universal testing machine at a 0.5 mm/min crosshead speed. Scanning electron microscopic fractographic and interfacial micromorphology analyses were performed. Data were analyzed using two-way ANOVA and Tukey's test (α= 0.05).
Mean bond strength (MPa) after 24 hours: C&B Cement 19.5 ± 3.8, RelyX ARC 40.8 ± 9.4, RelyX Unicem 31.3 ± 7.4; after 30 days: C&B Cement 24.5 ± 5.1, RelyX ARC 44.2 ± 8.5, RelyX Unicem 28.3 ± 7.1. The mean bond strengths of both dual-cure cements were significantly higher than that obtained with C&B Cement after 24 hours. A significant increase in the bond strength of C&B Cement was verified after 30 days, reaching values statistically equivalent to those produced by RelyX Unicem and RelyX ARC. The self-adhesive cement preserved the same level of bond strength after 30 days. Fractographic analysis revealed a prevalence of cohesive fractures in the hybrid layer for C&B Cement, mixed (cohesive in the cement, hybrid layer, and adhesive) for RelyX ARC, and cohesive in the cement for RelyX Unicem. No distinguishable hybrid layer or resin tags were observed in the interaction of RelyX Unicem with dentin.
The particular interaction of each cement with dentin results in specific bond strength and failure patterns that varied among groups in both evaluation times. Even though the self-adhesive cement tested exhibited no authentic hybrid layer, it was able to promote reliable adhesion with the underlying dentin.
评估三种商业树脂水门汀在 24 小时和 30 天浸水储存后对牙本质的间接复合树脂修复体的微拉伸粘结强度和界面微观形态。
暴露第三恒磨牙的中层牙本质（N = 30，每组 n = 10）。使用三种商业树脂水门汀粘结间接树脂复合修复体至牙本质：自固化 C&B 水门汀/All Bond 2、双固化 RelyX ARC/Adper Single Bond 2 和自粘结双固化 RelyX Unicem。在 37°C 下储存水后，将牙齿切割成具有粘结面积为 0.8 mm²的梁。以 0.5 mm/min 的十字头速度在万能试验机上测试试件。进行扫描电子显微镜断口和界面微观形态分析。使用双因素方差分析和 Tukey 检验（α= 0.05）对数据进行分析。
24 小时后平均粘结强度（MPa）：C&B 水门汀 19.5 ± 3.8，RelyX ARC 40.8 ± 9.4，RelyX Unicem 31.3 ± 7.4；30 天后：C&B 水门汀 24.5 ± 5.1，RelyX ARC 44.2 ± 8.5，RelyX Unicem 28.3 ± 7.1。两种双固化水门汀的平均粘结强度均显著高于 24 小时时 C&B 水门汀的粘结强度。C&B 水门汀的粘结强度在 30 天后显著增加，达到与 RelyX Unicem 和 RelyX ARC 相当的统计学水平。自粘结水门汀在 30 天后保持相同的粘结强度水平。断口分析显示，C&B 水门汀的混合层以混合性（水门汀、混合层和粘结剂中的粘结）为主，RelyX ARC 以混合性（粘结剂、混合层和粘结剂中的粘结）为主，RelyX Unicem 以粘结剂中的粘结性为主。在 RelyX Unicem 与牙本质的相互作用中，未观察到可识别的混合层或树脂标记。
每种水门汀与牙本质的特殊相互作用导致在两种评估时间内各组的粘结强度和失效模式存在差异。尽管所测试的自粘结水门汀没有真正的混合层，但它仍能与牙本质可靠地粘结。
