Background. Zirconia, with its excellent mechanical properties, has become a popular choice for esthetic and durable restorations due to the increasing demand of patients. It has overcome most of the limitations of all ceramic restorations. However, bonding to zirconia remains a challenge. Objectives. This study is aimed at assessing the effect of surface treatment with alkaline agents at two different temperatures on microshear bond strength (μSBS) of zirconia to composite resin. Materials and Methods. This in vitro, experimental study was conducted on zirconia blocks measuring  mm. The blocks were sandblasted with alumina powder and randomly assigned to 5 groups ( each). The blocks in groups 1 and 2 underwent surface treatment with sodium hydroxide (NaOH) and groups 3 and 4 with zirconium hydroxide (Zr(OH)4) at room temperature and 70°C. Group 5 served as the control group and did not receive any surface treatment. After the application of bonding agent and its light-curing, composite cylinders in plastic tubes were bonded to the surface of each block and cured. After incubation, they underwent μSBS test. Data were analyzed by one-way ANOVA and Tukey’s test (). Results. The μSBS was significantly higher in all intervention groups than that in the control group (). The μSBS in Zr(OH)4 groups was significantly higher than that in NaOH groups (). The mean μSBS of heated groups was slightly, but not significantly, higher than the corresponding room temperature groups (). Conclusion. Surface treatment of zirconia with NaOH and Zr(OH)4 alkaline agents can increase its μSBS to composite resin; Zr(OH)4 was significantly more effective than NAOH for this purpose, but heating did not have a significant effect on μSBS.

中文翻译：

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两种不同温度碱剂表面处理对氧化锆与复合树脂微剪切粘结强度的影响

背景。由于患者需求的不断增长，氧化锆以其优异的机械性能已成为美观和耐用修复体的流行选择。它克服了所有陶瓷修复体的大部分局限性。然而，与氧化锆的粘合仍然是一个挑战。目标。本研究旨在评估在两种不同温度下用碱性剂进行表面处理对氧化锆与复合树脂的微剪切粘合强度（μSBS）的影响。材料和方法。这项体外实验研究是对氧化锆块进行测量 毫米。这些块用氧化铝粉喷砂并随机分配到 5 组（每个）。第 1 组和第 2 组的块体在室温和 70°C 下用氢氧化钠 (NaOH) 进行表面处理，第 3 组和第 4 组的块体用氢氧化锆 (Zr(OH)4) 进行表面处理。第5组作为对照组，不接受任何表面处理。在施加粘合剂并光固化后，将塑料管中的复合圆柱体粘合到每个块的表面并固化。孵化后，他们进行μSBS测试。通过单向方差分析和 Tukey 检验对数据进行分析（）。 结果。所有干预组的 μ SBS 均显着高于对照组（）。 Zr(OH )4组的μSBS显着高于NaOH组(）。加热组的平均μ SBS 略高于相应的室温组，但不显着（）。 结论。用NaOH和Zr(OH)4碱性剂对氧化锆进行表面处理，可以提高其对复合树脂的μSBS；对于此目的，Zr(OH)4 明显比 NAOH 更有效，但加热对μSBS没有显着影响。