Department of Endodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey.
J Endod. 2011 Jun;37(6):832-5. doi: 10.1016/j.joen.2011.03.006. Epub 2011 Apr 21.
The objective of this study was to investigate and compare the effect of different light-emitting diode (LED) polymerization modes on the bond strength of a methacrylate-based sealer used with Resilon or gutta-percha.
Forty extracted single-rooted teeth were sectioned off below the cementoenamel junction, and the root canals were instrumented by using rotary instruments to ISO #30/0.06 taper. The roots were randomly assigned into 1 of the following groups for root canal obturation: (1) RealSeal + Resilon and (2) RealSeal + gutta-percha. In each group, specimens were further subgrouped according to the LED polymerization mode used to cure RealSeal: (1) standard (20 seconds of maximum intensity) and (2) exponential (5 seconds of exponential power increase, followed by 15 seconds of maximum intensity). Specimens were stored in 100% humidity for 1 week at 37 °C. Push-out test was performed at a crosshead speed of 1 mm/min on 2-mm-thick root slices obtained from coronal to apical direction. Multivariate analysis of variance and Tukey tests were used for statistical analysis of the data (P=.05). Failure modes were examined under the scanning electron microscope.
The tested polymerization modes had no significant effect on the bond strength values (P > .05). RealSeal + gutta-percha yielded significantly greater bond strength than RealSeal + Resilon (P < .05). In all groups, the bond strength values decreased significantly from coronal to apical direction (P < .05). Adhesive failure at the sealer-dentin interface was the predominant fracture mode.
The exponential photopolymerization mode had no significant advantage over the standard regimen in terms of dentin bond strength.
本研究旨在探讨和比较不同发光二极管（LED）聚合模式对使用 Resilon 或牙胶尖的甲基丙烯酸酯基密封剂粘结强度的影响。
将 40 颗离体单根牙在牙釉牙骨质界以下截成段，采用 ISO #30/0.06 锥度的旋转器械对根管进行器械预备。将牙根随机分为以下 2 组进行根管充填：（1）RealSeal + Resilon 和（2）RealSeal + 牙胶尖。每组根据用于固化 RealSeal 的 LED 聚合模式进一步分为亚组：（1）标准（最大强度 20 秒）和（2）指数（5 秒指数功率增加，随后 15 秒最大强度）。标本在 37°C 下 100%湿度中储存 1 周。在 2mm 厚的根切片上，从冠向根向以 1mm/min 的十字头速度进行推出试验。采用多变量方差分析和 Tukey 检验对数据进行统计分析（P=.05）。用扫描电子显微镜检查失效模式。
测试的聚合模式对粘结强度值没有显著影响（P＞.05）。RealSeal + 牙胶尖的粘结强度明显大于 RealSeal + Resilon（P＜.05）。在所有组中，粘结强度值从冠向根向显著降低（P＜.05）。在密封剂-牙本质界面处发生的黏附性失效是主要的断裂模式。
指数光聚合模式在牙本质粘结强度方面没有比标准方案有显著优势。
