Department of Orthodontics and Pediatric Dentistry, School of Dentistry, Univ of São Paulo, São Paulo, SP, Brazil.
Braz Oral Res. 2012 Nov-Dec;26(6):511-5. doi: 10.1590/s1806-83242012005000023. Epub 2012 Sep 27.
The aim of this in vitro study was to compare the degradation of resin-dentin bonds of an etch-and-rinse adhesive system to primary and permanent teeth. Flat superficial coronal dentin surfaces from 5 primary second molars and 5 permanent third molars were etched with phosphoric acid and bonded with an adhesive system (Adper Single Bond 2, 3M ESPE). Blocks of resin composite (Z250, 3M ESPE) were built up and the teeth sectioned to produce bonded sticks with a 0.8 mm² cross-sectional area. The sticks of each tooth were randomly divided and assigned to be subjected to microtensile testing immediately (24 h) or after aging by water storage (6 months). Data were analyzed by two-way repeated measures ANOVA and Tukey post hoc test (α = 0.05). Failure mode was evaluated using a stereomicroscope (400×). Microtensile values significantly decreased after the 6 months aging, independent of the dentin substrate. In 24 h, the values obtained to primary dentin were lower compared with permanent dentin. This difference was not maintained after aging. Adhesive/mixed failure was predominant in all experimental groups. In conclusion, degradation of resin-dentin bonds of the etch-and-rinse adhesive system occurred after 6 months of water storage; however, the reduction in bond strength values was higher for permanent teeth.
本体外研究旨在比较一种自酸蚀粘结系统对乳牙和恒牙牙本质粘结的降解作用。从 5 颗乳第二磨牙和 5 颗恒第三磨牙的表面浅层冠部牙本质上制取平面，用磷酸酸蚀并用粘结系统（Adper Single Bond 2，3M ESPE）粘结。复合树脂块（Z250，3M ESPE）构建完成后，将牙齿切割成具有 0.8mm² 截面积的粘结棒。将每个牙的粘结棒随机分组，分别进行微拉伸测试（24 小时）或老化后水储存（6 个月）。数据采用双向重复测量方差分析和 Tukey 事后检验（α = 0.05）进行分析。使用立体显微镜（400×）评估失效模式。6 个月老化后，微拉伸值显著降低，与牙本质基底无关。在 24 小时时，与恒牙本质相比，乳牙本质获得的数值较低。这种差异在老化后并未保持。所有实验组中主要的失效模式均为粘结/混合性失效。总之，自酸蚀粘结系统的牙本质粘结降解在水储存 6 个月后发生，但对恒牙的粘结强度值降低更为明显。
