Bonfante Gerson, Kaizer Osvaldo Bazzan, Pegoraro Luiz Fernando, do Valle Accácio Lins
Department of Prosthodontics, School of Dentistry of Bauru, University of São Paulo.
Braz Oral Res. 2007 Apr-Jun;21(2):159-64. doi: 10.1590/s1806-83242007000200011.
Proper selection of the luting agent is fundamental to avoid failure due to lack of retention in post-retained crowns. The objective of this study was to investigate the tensile bond strength and failure mode of glass fiber posts luted with different cements. Glass fiber posts were luted in 40 mandibular premolars, divided into 4 groups (n = 10): Group 1--resin-modified glass ionomer RelyX Luting; Group 2--resin-modified glass ionomer Fuji Plus; Group 3--resin cement RelyX ARC; Group 4--resin cement Enforce. Specimens were assessed by tensile strength testing and light microscopy analysis for observation of failure mode. The tensile bond strength values of each group were compared by ANOVA and Tukey test. The significance level was set at 5%. The failure modes were described as percentages. The following tensile strength values were obtained: Group 1--247.6 N; Group 2--256.7 N; Group 3--502.1 N; Group 4--477.3 N. There was no statistically significant difference between Groups 1 and 2 or between Groups 3 and 4, yet the resin cements presented significantly higher tensile bond strength values than those presented by the glass ionomer cements. Group 1 displayed 70% of cohesive failures, whereas Groups 2, 3 and 4 exhibited 70% to 80% of adhesive failures at the dentin-cement interface. We concluded that resin cements and glass ionomer cements are able to provide clinically sufficient retention of glass fiber posts, and that glass ionomer cements may be especially indicated when the application of adhesive techniques is difficult.
正确选择粘结剂是避免桩核冠因固位不足而失败的根本。本研究的目的是调查用不同粘结剂粘结的玻璃纤维桩的拉伸粘结强度和失败模式。将玻璃纤维桩粘结在40颗下颌前磨牙中，分为4组（n = 10）：第1组——树脂改性玻璃离子水门汀RelyX Luting；第2组——树脂改性玻璃离子水门汀Fuji Plus；第3组——树脂粘结剂RelyX ARC；第4组——树脂粘结剂Enforce。通过拉伸强度测试和光学显微镜分析评估样本，以观察失败模式。通过方差分析和Tukey检验比较每组的拉伸粘结强度值。显著性水平设定为5%。将失败模式描述为百分比。获得以下拉伸强度值：第1组——247.6 N；第2组——256.7 N；第3组——502.1 N；第4组——477.3 N。第1组和第2组之间以及第3组和第4组之间没有统计学上的显著差异，但树脂粘结剂的拉伸粘结强度值明显高于玻璃离子水门汀的拉伸粘结强度值。第1组显示70%的内聚性失败，而第2、3和4组在牙本质-粘结剂界面处显示70%至80%的粘结性失败。我们得出结论，树脂粘结剂和玻璃离子水门汀能够在临床上为玻璃纤维桩提供足够的固位，并且当粘结技术应用困难时，玻璃离子水门汀可能特别适用。
