Objectives:To morphologically evaluate the permeability of different commercial dental adhesives using scanning electron microscopy.Methods:Seven adhesive systems were evaluated: one three-step system (Scotchbond Multi-Purpose - MP); one two-step self-etching primer system (Clearfil SE Bond – SE); three two-step etch-and-rinse systems (Single Bond 2 – SB; Excite – EX; One-Step – OS); and two single-step self-etching adhesives (Adper Prompt – AP; One-Up Bond F – OU). The mixture of primer and bond agents of the Clearfil SE Bond system (SE-PB) was also tested. The adhesives were poured into a brass mold (5.8 mm x 0.8 mm) and light-cured for 80 s at 650 mW/cm2. After a 24 h desiccation process, the specimens were immersed in a 50% ammoniac silver nitrate solution for tracer permeation. Afterwards, they were sectioned in ultra-fine slices, carbon-coated, and analyzed under backscattered electrons in a scanning electron microscopy.Results:MP and SE showed slight and superficial tracer permeation. In EX, SB, and OS, permeation extended beyond the inner superficies of the specimens. SE-PB did not mix well, and most of the tracer was precipitated into the primer agent. In AP and OU, “water-trees” were observed all over the specimens.Conclusions:Different materials showed distinct permeability in aqueous solution. The extent of tracer permeation varied according to the composition of each material and it was more evident in the more hydrophilic and solvated ones.
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机译：目的：通过扫描电子显微镜对形态不同的商品牙科用胶粘剂的渗透性进行形态学评估。一个两步自蚀刻底漆系统（Clearfil SE Bond – SE）;三个三步蚀刻和冲洗系统（单键2 – SB;激发– EX;一步– OS）;以及两种单步自蚀刻胶粘剂（Adper Prompt – AP;单面粘结F – OU）。还测试了Clearfil SE键合系统（SE-PB）的底漆和键合剂的混合物。将粘合剂倒入黄铜模具（5.8 mm x 0.8 mm）中，并以650 mW / cm2的光固化80 s。经过24小时的干燥过程，将样品浸入50％的氨水硝酸银溶液中以示踪剂渗透。然后，将它们切成超细切片，涂碳，并在扫描电子显微镜下在反向散射电子下进行分析。结果：MP和SE显示出轻微的表面示踪剂渗透。在EX，SB和OS中，渗透范围扩展到样本的内部表面。 SE-PB混合不好，大多数示踪剂沉淀到底漆中。在AP和OU中，在整个标本中都观察到“水树”。结论：不同的材料在水溶液中显示出明显的渗透性。示踪剂渗透的程度随每种物质的组成而变化，在亲水性和溶剂化程度更高的物质中更明显。
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