Mannocci F, Sherriff M, Ferrari M, Watson T F
University of Siena, Italy.
Am J Dent. 2001 Aug;14(4):200-4.
To evaluate the bond strength of two dentin-bonding systems to root canal dentin.
Six central incisors, extracted for periodontal reasons, were endodontically treated, no obturation of the root canal space was performed. The teeth were cut parallel to their long axis. One half of each tooth was randomly assigned to one of two experimental groups. The teeth of the first group were treated with All-Bond 2 dental adhesive and those of the second group with Panavia F. The root canal dentin was conditioned as suggested by the manufacturers and, after the application of the dental adhesives, a layer of resin-based composite was polymerized over the adhesive layer. After the composite had completely set, the sections were prepared for microtensile test and kept in a wet environment at a relative humidity of 90 +/- 2% measured with a digital relative humidity meter and at a temperature of 22 degrees C for 24 hrs. The specimens were sectioned perpendicularly to the bonded interface, into slabs 1.5 mm thick (10 sections for each experimental group). The slabs were then trimmed by super fine diamond burs for the microtensile bond test with the narrowest region located at the respective bonded interface. The thickness of the slab was then exactly established by three measurements performed in three points of each slab by a digital micrometer. The specimens were then subjected to a tensile force at a crosshead speed of 0.2 mm/min. The test was observed using a confocal microscope and the failure modes were noted. The load at failure was registered and the bonded area was measured using a confocal microscope at a magnification of x25 in conjunction with an image-processing program. The failure data were analyzed using the Wilcoxon-Gehan test with exact non-parametric inference.
The mean value at failure was the same for the two experimental groups (17.1 MPa). There was no statistically significant difference between Panavia F and All-Bond 2 (P> 0.8671). Most of the specimens showed a debonding of the adhesive from the hybrid layer. The results showed that the bond strength of the two bonding systems tested to the dentin of the root canal are slightly lower than to those obtained with the latest adhesive systems, in the coronal dentin.
评估两种牙本质粘结系统与根管牙本质的粘结强度。
因牙周原因拔除的6颗中切牙，进行根管治疗，未对根管腔进行充填。将牙齿沿其长轴平行切割。每颗牙齿的一半随机分配到两个实验组之一。第一组牙齿用全粘结2型牙科粘结剂处理，第二组牙齿用帕纳维亚F处理。按照制造商的建议对根管牙本质进行预处理，在应用牙科粘结剂后，在粘结剂层上聚合一层树脂基复合材料。复合材料完全固化后，制备切片用于微拉伸试验，并在相对湿度为90±2%（用数字相对湿度计测量）、温度为22℃的潮湿环境中保存24小时。将标本垂直于粘结界面切成1.5毫米厚的薄片（每个实验组10个切片）。然后用超细金刚石车针修整薄片，用于微拉伸粘结试验，最窄区域位于各自的粘结界面处。然后通过在每个薄片的三个点进行三次测量，用数字千分尺精确确定薄片的厚度。然后以0.2毫米/分钟的十字头速度对标本施加拉力。使用共聚焦显微镜观察试验并记录失效模式。记录失效时的载荷，并使用共聚焦显微镜在25倍放大倍数下结合图像处理程序测量粘结面积。使用具有精确非参数推断的威尔科克森 - 盖汉检验分析失效数据。
两个实验组的失效平均值相同（17.1兆帕）。帕纳维亚F和全粘结2型之间无统计学显著差异（P>0.8671）。大多数标本显示粘结剂与混合层脱粘。结果表明，测试的两种粘结系统与根管牙本质相比，粘结强度略低于与最新粘结系统在冠部牙本质中获得的粘结强度。
