De Goes Mario Fernando, Giannini Marcelo, Foxton Richard Mark, Nikaido Toru, Tagami Junji
Department of Restorative Dentistry, Piracicaba School of Dentistry, State University of Campinas, Piracicaba, SP, Brazil.
J Prosthet Dent. 2007 Apr;97(4):223-8. doi: 10.1016/j.prosdent.2007.02.014.
Since bonding agent effectiveness is usually evaluated on coronal substrates, available knowledge for judging the effectiveness of bonds to root dentin is insufficient.
The objective of this study was to evaluate the bond strength of 2 adhesive systems to crown, cervical finish line, and post space dentin.
Twenty bovine maxillary incisors were used in this study. Teeth were sectioned along the cemento-enamel junction using a low-speed diamond blade to separate the crowns and roots. Then the crowns and roots were each divided into 2 groups, according to the 2 adhesive systems tested (n=10). The facial enamel surfaces of the crowns were abraded with 600-grit silicon carbide paper to expose flat, midcoronal dentin surfaces. Drills and a diamond rotary cutting instrument were used in a low-speed handpiece to prepare post spaces in the root canals. The same diamond rotary instrument was used to prepare horizontally flat surfaces in the cervical areas, similar to the horizontal aspect of a shoulder finish line. Composite resin was placed incrementally into the post spaces, over the flat cervical shoulder areas, and on the coronal dentin. Bonded beam specimens (0.5 mm(2) of cross-sectional area) derived from crown, cervical finish line, and post space dentin, were prepared for microtensile bond testing and tested in tension. Data were analyzed using 2-way ANOVA and Tukey post hoc test (alpha=.05). Failure patterns of tested specimens were analyzed using scanning electron microscopy.
The mean tensile bond strength values (SD) (MPa) were: Single Bond-crown: 29.8 (4.0); Single Bond-finish line: 18.7 (4.3); Single Bond-post space: 17.0 (4.8); Clearfil SE Bond-crown: 30.1 (6.4); Clearfil SE Bond-finish line: 30.4 (5.3); and Clearfil SE Bond-post space: 17.0 (4.2). Bond strengths to post space dentin were lower than those to coronal dentin for both adhesives (P<.001). However, no significant difference was observed between coronal and finish line dentin for Clearfil SE Bond.
Bond strength was reduced when adhesives were used in bonding to post space dentin. Cervical finish line sites bonded using Clearfil SE Bond adhesive yielded bond strength similar to that of coronal dentin sites.
由于粘结剂的有效性通常是在牙冠基底上进行评估的，因此判断粘结剂与牙根牙本质粘结有效性的现有知识不足。
本研究的目的是评估两种粘结系统与牙冠、颈部边缘线及桩道牙本质的粘结强度。
本研究使用了20颗牛上颌切牙。使用低速金刚石锯片沿牙骨质-釉质界将牙齿切割，分离牙冠和牙根。然后，根据所测试的两种粘结系统，将牙冠和牙根各分为2组（每组n = 10）。用600目碳化硅砂纸打磨牙冠的唇面釉质，以暴露平坦的牙冠中部牙本质表面。使用低速手机中的钻头和金刚石旋转切割器械在根管内制备桩道。使用相同的金刚石旋转器械在颈部区域制备水平平坦表面，类似于肩台边缘线的水平方向。将复合树脂分层放置在桩道、平坦的颈部肩台区域及牙冠牙本质上。制备来自牙冠、颈部边缘线及桩道牙本质的粘结梁试件（横截面积0.5 mm²），用于微拉伸粘结测试并进行拉伸试验。数据采用双向方差分析和Tukey事后检验进行分析（α = 0.05）。使用扫描电子显微镜分析测试试件的断裂模式。
平均拉伸粘结强度值（标准差）（MPa）为：Single Bond粘结牙冠：29.8（4.0）；Single Bond粘结边缘线：18.7（4.3）；Single Bond粘结桩道：17.0（4.8）；Clearfil SE Bond粘结牙冠：30.1（6.4）；Clearfil SE Bond粘结边缘线：30.4（5.3）；Clearfil SE Bond粘结桩道：17.0（4.2）。两种粘结剂与桩道牙本质的粘结强度均低于与牙冠牙本质的粘结强度（P < 0.001）。然而，对于Clearfil SE Bond粘结剂，牙冠和边缘线牙本质之间未观察到显著差异。
当粘结剂用于粘结桩道牙本质时，粘结强度降低。使用Clearfil SE Bond粘结剂粘结的颈部边缘线部位的粘结强度与牙冠牙本质部位相似。
