吸水对充填复合树脂抗弯性能的影响

目的：研究吸水对充填复合树脂抗弯强度和弹性模量的影响。方法将混合型前牙充填复合树脂(GDA)和通用型充填复合树脂(GCK)根据ISO FDIS 4049：1999标准制备为大小(25±2)mm ×(2±0.1)mm ×(2±0.1)mm的柱状试件,分为GDA1,GDA30,GDA90,GDA150,GCK1,GCK30,GCK90,GCK150共8组,每组13个样本。分别放入(37±1)oC的去离子水中浸泡1天、30天、90天、150天。利用三点弯曲实验测量并计算试件的三点抗弯强度和挠曲弹性模量。在体视显微镜和扫描电子显微镜下观察断面形貌。结果 GDA30和GCK30组分别与GDA1和GCK1组相比,抗弯强度的差异均无统计学意义。 GDA90及GDA150组的抗弯强度随浸水时间延长而逐渐降低,差异具有统计学意义；GCK90及GCK150组与GCK1组抗弯强度的差异具有统计学意义,但GCK90及GCK150组之间抗弯强度的差异无统计学意义。 GDA及GCK不同浸水时间的各组之间,其弹性模量的差异无统计学意义。结论在浸水150天的有限时间内,吸水会使充填复合树脂GDA和GCK的抗弯强度降低,但不会影响其弹性模量。

Effects of water on the flexural strength and modulus of elasticity of resin-matrix composites

Objective To investigate the effect of water on the flexural strength and modulus of elasticity of two types of resin-matrix composites. Methods An anterior composite ( GDA ) and a posterior composite ( GCK ) were evaluated. A total of 104 specimens (25 ± 2)mm × (2 ± 0. 1)mm × (2 ± 0. 1)mm were prepared according to ISO 4049. Flexural strength and modulus of elasticity of the specimens were measured by three-point bending test during 150 days of water storage at 37℃. The data were analyzed by one-way ANOVA and Tukey’s post hoc test. Results Statistically different flexural strength was observed between GDA1 and GDA90 , GDA90 and GDA150 , GCK1 and GCK90 , as well as GCK1 and GCK150 . The modulus of elasticity was not significantly different. Conclusion The flexural strength of GDA and GCK decreased during the 150 days water storage, but their modulus of elasticity did not change.