Ai H, Nagai M
School of Stomatology, China Medical University, 143 Nanjing Street, Heping District, Shenyang 110002, China.
Dent Mater J. 2000 Jun;19(2):153-63. doi: 10.4012/dmj.19.153.
We investigated how the thickness of an adhesive layer between two Co-Cr alloy plates affected the mode I fracture toughness of dental adhesive resin by varying the type of resin using a double cantilever beam (DCB) test. Two typical adhesive resins (PV and SB) were used. The adhesive layers of the DCB test specimens were 20, 100 and 200 microns thick. The fracture modes of PV differed with the thickness of the adhesive layer, such as interface fracture at 20 microns thickness, and similar cohesive fracture at 100 and 200 microns thickness. In the case of SB, crack-propagating areas were observed as cohesive fractures in all test specimens with different adhesive layer thickness, and the surfaces of these areas became remarkably rougher as the thickness of the adhesive layer increased. The fracture toughness of PV was not affected by the differences in thickness between the 100 and 200 microns adhesive layers, but there was a notable decrease in fracture toughness when the adhesive layer decreased to a thickness of 20 microns. That of SB showed a tendency to increase as the adhesive layer became thicker.
我们通过使用双悬臂梁（DCB）试验改变树脂类型，研究了两块钴铬合金板之间粘合剂层的厚度如何影响牙科粘合剂树脂的I型断裂韧性。使用了两种典型的粘合剂树脂（PV和SB）。DCB试验样品的粘合剂层厚度分别为20、100和200微米。PV的断裂模式随粘合剂层厚度而不同，例如20微米厚度时为界面断裂，100和200微米厚度时为类似的内聚断裂。对于SB，在所有具有不同粘合剂层厚度的试验样品中，裂纹扩展区域均观察为内聚断裂，并且随着粘合剂层厚度增加，这些区域的表面变得明显更粗糙。PV的断裂韧性不受100和200微米粘合剂层之间厚度差异的影响，但当粘合剂层厚度减小到20微米时，断裂韧性显著降低。SB的断裂韧性显示出随着粘合剂层变厚而增加的趋势。
