J Adhes Dent. 2019;21(1):59-66. doi: 10.3290/j.jad.a41986.
To evaluate the effects of double application of self-etch adhesives on their microtensile bond strength (μTBS) to dentin, as well as the hardness (H) of resin-dentin interfacial structures.
Midcoronal dentin surfaces (n = 45) were polished with 180-grit SiC paper and randomly allocated to 9 groups based on three adhesives - Scotchbond Universal Adhesive (SB), G Premio Bond (GP), and Clearfil Megabond 2 (MB) - and three application modes: single application (S), double application with light curing after each application (DL), and double application with light curing only at the end (D). Following composite-resin build up and water storage (37°C; 24 h), μTBS were obtained. The hardness of adhesive, resin-dentin interface and dentin were evaluated by nanoindentation. The μTBS and H data were analyzed by two-way ANOVA to demonstrate the effects of adhesive and application mode as well as their interaction, followed by Tukey's test (α = 0.05). Fracture modes were determined using a stereomicroscope.
μTBS and H were significantly affected by the adhesives and their application modes (p ˂ 0.001). Double application significantly increased the µTBS and H of adhesive and resin-dentin interface (p ˂ 0.05). SB and MB showed significantly higher µTBS than GP (p ˂ 0.05).
Double applications during bonding of dentin having clinically relevant smear layers were beneficial for three contemporary self-etch adhesives. The improvement in bonding performance is believed to be the result of increased chemical interaction, better solvent removal, and improved resin infiltration, leading to improved mechanical properties of the resin-dentin interface or thicker adhesive layers providing improved stress distribution.
评估自酸蚀黏结剂双层涂布对牙本质微拉伸黏结强度（μTBS）和树脂-牙本质界面硬度（H）的影响。
用 180 号碳化硅砂纸对中切牙釉牙骨质界牙本质表面进行机械抛光，然后根据三种黏结剂（Scotchbond Universal Adhesive [SB]、G Premio Bond [GP]和 Clearfil Megabond 2 [MB]）和三种涂布方式（单次涂布 S、两次涂布且两次涂布后均光固化 DL、两次涂布仅最后一次光固化 D）将 45 个样本随机分组。复合树脂堆积完成后在 37°C 水中储存 24 小时，然后测试 μTBS。纳米压痕法用于评估黏结剂、树脂-牙本质界面和牙本质的硬度。采用双因素方差分析比较黏结剂和涂布方式及其交互作用对 μTBS 和 H 的影响，然后采用 Tukey 检验（α=0.05）进行多重比较。用体视显微镜观察并确定断裂模式。
黏结剂和涂布方式对 μTBS 和 H 均有显著影响（p ˂ 0.001）。双层涂布显著提高了黏结剂和树脂-牙本质界面的 μTBS 和 H（p ˂ 0.05）。SB 和 MB 的 μTBS 显著高于 GP（p ˂ 0.05）。
在有临床相关玷污层的牙本质黏结时双层涂布三种当代自酸蚀黏结剂是有益的。黏结性能的提高可能归因于化学性黏结增强、更好的溶剂去除以及树脂渗透增加，从而改善了树脂-牙本质界面的机械性能或增加了黏结剂厚度，进而改善了应力分布。
