EFFECT OF ADHESIVE LAYER THICKNESS ON THE BOND STRENGTH OF A ZINC POLYCARBOXYLATE DENTAL CEMENT
EFFECT OF ADHESIVE LAYER THICKNESS ON THE BOND STRENGTH OF A ZINC POLYCARBOXYLATE DENTAL CEMENT
复制标题
DOI：
10.1016/0142-9612(95)98279-n
复制
发表时间：
1995-01-01
期刊：
影响因子：
14
通讯作者：
NICHOLSON, JW
中科院分区：
文献类型：
--
作者：
AKINMADE, AO;NICHOLSON, JW
本研究报告了不同厚度的商用聚羧酸锌牙科粘固剂对其在金属对金属单搭接接头中的粘附力的影响。厚度是在一个专门设计的设备外部控制，而不是通过列入等维玻璃球，如以前所做的。结果表明，粘结接头中水泥层的厚度对水泥的拉剪粘结强度和破坏形态均有影响。因此，这些结果证实了先前的发现，即聚羧酸锌层存在最佳厚度。对于所研究的特定水泥PolyF Plus（De Trey，Dentsply，Weybridge，Surrey，UK），粘合剂层的最佳厚度为205 μ m，发现其平均剪切粘结强度为4.03 MPa。使用应力分析，最大剪切和拉伸应力，τ（12（最大））和西格玛（11（最大）），也已获得。这些分析表明，当粘合剂层厚度低于100 μ m时，接头在水泥层和搭接接头之间的界面处失效。这是由于在具有薄粘合剂层的粘合接头中的高应力集中。另一方面，较厚的关节内的粘合剂层失败，因为在这些关节的拉伸应力的贡献更大。
This study reports the effect of varying the thickness of a commercial zinc polycarboxylate dental cement on its adhesion in a metal-to-metal single lap joint. The thickness was controlled externally in a specially designed apparatus, rather than by the inclusion of isodimensional glass spheres, as has been done previously. The results show that both the tensile shear bond strength and the mode of failure of the cement are influenced by the thickness of the cement layer in the bonded joints. Hence, these results confirm previous findings that there is an optimum thickness for the zinc polycarboxylate layer. They also show that failure is more likely to be cohesive with thicker layers.The optimum thickness of the adhesive layer was 205 mu m for the particular cement studied, PolyF Plus (De Trey, Dentsply, Weybridge, Surrey, UK), for which the average shear bond strength was found to be 4.03 MPa. Using stress analysis, the maximum shear and tensile stresses, tau(12(max)) and sigma(11(max)), have also been obtained. These analyses showed that joints failed at the interface between the cement layers and the lap joint at adhesive layer thicknesses of below 100 mu m. This resulted from the high stress concentrations in bonded joints with thin adhesive layers. On the other hand, thicker joints failed cohesively within the adhesive layer because of greater contributions from tensile stresses in these joints.