Restorative Dentistry Department, Faculty of Oral and Dental Medicine, Cairo University, Egypt.
J Adv Res. 2016 Mar;7(2):263-9. doi: 10.1016/j.jare.2015.06.003. Epub 2015 Jun 20.
The reparability of dual-cured resin composite core buildup materials using a light-cured one following one week or three months storage, prior to repair was evaluated. Two different dual-cured resin composites; Cosmecore™ DC automix and Clearfil™ DC automix core buildup materials and a light-cured nanofilled resin composite; Filtek™ Z350 XT were used. Substrate specimens were prepared (n = 12/each substrate material) and stored in artificial saliva at 37 °C either for one week or three months. Afterward, all specimens were ground flat, etched using Scotchbond™ phosphoric acid etchant and received Single Bond Universal adhesive system according to the manufacturers' instructions. The light-cured nanofilled resin composite (Filtek™ Z350 XT) was used as a repair material buildup. To determine the cohesive strength of each solid substrate material, additional specimens from each core material (n = 12) were prepared and stored for the same periods. Five sticks (0.8 ± 0.01 mm(2)) were obtained from each specimen (30 sticks/group) for microtensile bond strength (μTBS) testing. Modes of failure were also determined. Two-way ANOVA revealed a significant effect for the core materials but not for the storage periods or their interaction. After one week, dual-cured resin composite core buildup materials (Cosmecore™ DC and Clearfil™ DC) achieved significantly higher repair μTBS than the light-cured nanofilled resin composite (Filtek™ Z350 XT). However, Clearfil™ DC revealed the highest value, then Cosmecore™ DC and Filtek™ Z350 XT, following storage for 3-month. Repair strength values recovered 64-86% of the cohesive strengths of solid substrate materials. The predominant mode of failure was the mixed type. Dual-cured resin composite core buildup materials revealed acceptable repair bond strength values even after 3-month storage.
研究了在修复前一周或三个月储存后，用光固化的单组分树脂复合材料修复双固化树脂复合核修复材料的可修复性。使用了两种不同的双固化树脂复合材料：Cosmecore™ DC 自混合和 Clearfil™ DC 自混合核修复材料以及光固化纳米复合树脂复合材料：Filtek™ Z350 XT。制备基底标本（每种基底材料 n = 12/）并在 37°C 的人工唾液中储存一周或三个月。之后，所有标本均磨平，用 Scotchbond™磷酸酸蚀剂蚀刻，并根据制造商的说明使用 Single Bond Universal 胶粘剂系统。用光固化纳米复合树脂复合材料（Filtek™ Z350 XT）作为修复材料。为了确定每个固体基底材料的内聚强度，从每种核材料（n = 12）中制备并储存了额外的标本。从每个标本中获得 5 个棒（0.8 ± 0.01mm²）（每组 30 个棒）进行微拉伸粘结强度（μTBS）测试。还确定了失效模式。双因素方差分析显示核材料有显著影响，但储存期或其相互作用没有显著影响。一周后，双固化树脂复合核修复材料（Cosmecore™ DC 和 Clearfil™ DC）的修复 μTBS 显著高于光固化纳米复合树脂（Filtek™ Z350 XT）。然而，Clearfil™ DC 表现出最高值，其次是 Cosmecore™ DC 和 Filtek™ Z350 XT，在储存 3 个月后。修复强度值恢复了固体基底材料内聚强度的 64-86%。主要失效模式为混合模式。即使在储存 3 个月后，双固化树脂复合核修复材料仍显示出可接受的修复粘结强度值。
