Department of Restorative Dentistry, São José dos Campos School of Dentistry, UNESP- Univ Estadual Paulista, São Paulo, Brazil.
Oper Dent. 2013 Jul-Aug;38(4):447-55. doi: 10.2341/11-383-L. Epub 2012 Dec 5.
The aim of this study was to investigate the influence of Nd:YAG laser on the shear bond strength to enamel and dentin of total and self-etch adhesives when the laser was applied over the adhesives, before they were photopolymerized, in an attempt to create a new bonding layer by dentin-adhesive melting.
One-hundred twenty bovine incisors were ground to obtain flat surfaces. Specimens were divided into two substrate groups (n=60): substrate E (enamel) and substrate D (dentin). Each substrate group was subdivided into four groups (n=15), according to the surface treatment accomplished: X (Xeno III self-etching adhesive, control), XL (Xeno III + laser Nd:YAG irradiation at 140 mJ/10 Hz for 60 seconds + photopolymerization, experimental), S (acid etching + Single Bond conventional adhesive, Control), and SL (acid etching + Single Bond + laser Nd:YAG at 140 mJ/10 Hz for 60 seconds + photopolymerization, experimental). The bonding area was delimited with 3-mm-diameter adhesive tape for the bonding procedures. Cylinders of composite were fabricated on the bonding area using a Teflon matrix. The teeth were stored in water at 37°C/48 h and submitted to shear testing at a crosshead speed of 0.5 mm/min in a universal testing machine. Results were analyzed with three-way analysis of variance (ANOVA; substrate, adhesive, and treatment) and Tukey tests (α=0.05). ANOVA revealed significant differences for the substrate, adhesive system, and type of treatment: lased or unlased (p<0.05). The mean shear bond strength values (MPa) for the enamel groups were X=20.2 ± 5.61, XL=23.6 ± 4.92, S=20.8 ± 4.55, SL=22.1 ± 5.14 and for the dentin groups were X=14.1 ± 7.51, XL=22.2 ± 6.45, S=11.2 ± 5.77, SL=15.9 ± 3.61. For dentin, Xeno III self-etch adhesive showed significantly higher shear bond strength compared with Single Bond total-etch adhesive; Nd:YAG laser irradiation showed significantly higher shear bond strength compared with control (unlased).
Nd:YAG laser application prior to photopolymerization of adhesive systems significantly increased the bond strength to dentin.
本研究旨在探讨 Nd:YAG 激光对全酸蚀和自酸蚀粘结剂在粘结前应用于粘结剂表面（在光聚合之前）时对牙釉质和牙本质粘结强度的影响，试图通过牙本质-粘结剂的熔融来形成新的粘结层。
120 颗牛切牙被研磨以获得平面。标本分为两组（n=60）：基底 E（牙釉质）和基底 D（牙本质）。每个基底组根据完成的表面处理进一步分为四组（n=15）：X（Xeno III 自酸蚀粘结剂，对照）、XL（Xeno III + Nd:YAG 激光 140 mJ/10 Hz 照射 60 秒+光聚合，实验）、S（酸蚀+Single Bond 传统粘结剂，对照）和 SL（酸蚀+Single Bond + Nd:YAG 激光 140 mJ/10 Hz 照射 60 秒+光聚合，实验）。在粘结过程中，用 3-mm 直径的压敏胶带限定粘结区域。使用聚四氟乙烯基质在粘结区域上制造复合圆柱体。牙齿在 37°C/48 h 的水中储存，并在万能试验机上以 0.5mm/min 的十字头速度进行剪切测试。使用三因素方差分析（ANOVA；基底、粘结剂和处理）和 Tukey 检验（α=0.05）对结果进行分析。ANOVA 显示了基底、粘结系统和处理类型（激光或非激光）的显著差异（p<0.05）。牙釉质组的平均剪切粘结强度值（MPa）为 X=20.2±5.61、XL=23.6±4.92、S=20.8±4.55、SL=22.1±5.14，牙本质组为 X=14.1±7.51、XL=22.2±6.45、S=11.2±5.77、SL=15.9±3.61。对于牙本质，Xeno III 自酸蚀粘结剂的剪切粘结强度明显高于全酸蚀粘结剂 Single Bond；Nd:YAG 激光照射的剪切粘结强度明显高于对照（非激光照射）。
在粘结剂光聚合之前应用 Nd:YAG 激光显著提高了对牙本质的粘结强度。
