This study evaluated the effects of Erbium-doped yttrium aluminium garnet (Er:YAG) laser settings and dentin bonding agents on ultramorphological characteristics of resin–laser–irradiated dentin interfaces and dentin bond strength (BS) of these adhesive systems. Additionally, dentin depth affected by Er:YAG laser irradiations was measured. The experiments were performed on occlusal dentin surfaces of third molars that were flattened with 600-grit SiC sandpaper. Treated-dentin with laser settings (250 mJ/4 Hz and 160 mJ/10 Hz) were the experimental groups, while SiC abraded dentin was the control. These three dentin treatments and three adhesives (two self-etchings and one etch-&-rinse adhesive) formed nine groups for the ultramorphology of laser-ablated dentin-adhesives interfacial analysis, using a transmission electron microscope (TEM). For BS (n = 8), the same nine groups were tested with addition of the two evaluation times (24 h after sample preparation or 1 year). The depths of Er:YAG laser effects into the dentin were measured using a TEM (n = 10). Ablated-dentin depth and BS data were analyzed by one- and three-way ANOVA, respectively, and Tukey's test (α = 0.05). Hybrid layer formation was only observed for controls, while for laser-treated dentin, adhesives were bonded to dentin with resin tags formation. Laser settings reduced the BS for all adhesives at 24 h, while at 1 year, etch-&-rinse adhesive presented the highest BS, regardless treatment (control or laser settings). Dentin depth affected by laser settings was similar. The laser irradiation altered the bonding mechanism of the adhesives to dentin and reduced the BS for self-etching adhesives. Etch-&-rinse adhesive yielded the highest BS at 1 year. Laser settings similarly affected the dentin in depth.

中文翻译：

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Er:YAG 激光照射设置对牙本质粘附界面超形态和牙本质粘合强度的影响

本研究评估了掺铒钇铝石榴石 (Er:YAG) 激光设置和牙本质粘合剂对树脂-激光照射牙本质界面的超形态特征和这些粘合系统的牙本质粘合强度 (BS) 的影响。此外，测量了受 Er:YAG 激光照射影响的牙本质深度。实验是在用 600-grit SiC 砂纸磨平的第三磨牙的咬合牙本质表面上进行的。用激光设置（250 mJ/4 Hz 和 160 mJ/10 Hz）处理的牙本质是实验组，而 SiC 磨蚀牙本质是对照组。这三种牙本质处理和三种粘合剂（两种自蚀刻和一种蚀刻和冲洗粘合剂）形成了九组，用于使用透射电子显微镜 (TEM) 进行激光烧蚀牙本质粘合剂界面分析的超形态学。n  = 8），相同的九组进行了测试，增加了两个评估时间（样品制备后 24 小时或 1 年）。使用 TEM ( n  = 10)测量 Er:YAG 激光对牙本质的影响深度。消融牙本质深度和 BS 数据分别通过单因素和三因素 ANOVA 和 Tukey 检验 ( α = 0.05)。仅在对照中观察到混合层的形成，而对于激光处理的牙本质，粘合剂通过树脂标签形成与牙本质结合。激光设置在 24 小时降低了所有粘合剂的 BS，而在 1 年时，无论处理（控制或激光设置），蚀刻和冲洗粘合剂的 BS 均最高。受激光设置影响的牙本质深度相似。激光照射改变了粘合剂与牙本质的粘合机制，并降低了自蚀刻粘合剂的 BS。蚀刻和冲洗粘合剂在 1 年时产生最高的 BS。激光设置同样影响牙本质的深度。