Tantbirojn D, Cheng Y S, Versluis A, Hodges J S, Douglas W H
Minnesota Dental Research Center for Biomaterials and Biomechanics, Department of Oral Science, University of Minnesota School of Dentistry, Minneapolis 55455, USA.
J Dent Res. 2000 Jan;79(1):41-8. doi: 10.1177/00220345000790010601.
This study addresses the anticipated problem of discriminating among high-performing dentin adhesives. The simplicity of the nominal shear bond test, despite being heavily criticized, has made it a routine procedure for the determination of bonding efficacy. A fracture mechanics approach has been suggested as a better assessment of bonding efficacy (Versluis et al., 1997). However, experimental complexity is a major limitation. It is hypothesized that a new, simplified interfacial fracture toughness test (Lin, 1994) will evaluate bonding agents differently if compared with the traditional shear bond test. Therefore, the objective of this study was to compare the performances of six dentin bonding agents subjected to the interfacial fracture toughness test (critical plane strain energy release rate) or to the nominal shear bond test (shear bond strength). Their performances were also characterized by scanning electron micrography of the fracture surfaces for evidence of dentin cohesive failure. Statistical analyses showed only marginal differences between these determinants of the two tests. However, when the analysis was applied only to the materials that had 100% frequency of dentin cohesive failure in shear testing, which also had high bonding efficacy, the difference in adhesive strengths between the two tests became significant. The reliability of the nominal shear test is questioned when dentin cohesive failure occurs, which usually is associated with high bonding efficacy. Since it is expected that bonding efficacy will increase further, the interfacial fracture toughness test is the preferred methodology to distinguish among high-performing dentin adhesives.
本研究探讨了区分高性能牙本质粘结剂这一预期问题。名义剪切粘结试验尽管备受批评，但其操作简单，已成为测定粘结效果的常规方法。有人提出采用断裂力学方法能更好地评估粘结效果（Versluis等人，1997年）。然而，实验复杂性是一个主要限制因素。据推测，一种新的、简化的界面断裂韧性试验（Lin，1994年）与传统的剪切粘结试验相比，对粘结剂的评估会有所不同。因此，本研究的目的是比较六种牙本质粘结剂在界面断裂韧性试验（临界平面应变能释放率）或名义剪切粘结试验（剪切粘结强度）中的性能表现。还通过对断裂表面进行扫描电子显微镜观察，以确定牙本质内聚性破坏的证据，从而对它们的性能进行表征。统计分析表明，这两种试验的这些决定因素之间仅存在微小差异。然而，当仅对在剪切试验中牙本质内聚性破坏频率为100%且粘结效果也较高的材料进行分析时，两种试验的粘结强度差异变得显著。当出现牙本质内聚性破坏时，名义剪切试验的可靠性受到质疑，而这种破坏通常与高粘结效果相关。由于预计粘结效果会进一步提高，界面断裂韧性试验是区分高性能牙本质粘结剂的首选方法。
