冷热循环对硅橡胶软衬拉伸强度的影响

目的：研究冷热循环对2种不同方式固化的硅橡胶软衬拉伸强度的影响。方法：选用Sofreliner MS自凝硅橡胶软衬、Silagum硅橡胶软衬,分别与α-RESIN热凝基托树脂块进行粘接制作圆柱形试件各30个。37℃蒸馏水浸泡24h作为对照组,余试件分别冷热循环5 000、10 000、20 000、30 000次后各取出6个进行拉伸强度测定,观察断裂模式。结果：Sofreliner MS软衬、Silagum软衬各组间拉伸强度没有统计学差异（P〈0.05）;Silagum硅橡胶软衬各组拉伸强度均显著大于Sofreliner MS自凝硅橡胶软衬（P〈0.05）。结论：冷热循环30 000次对本实验条件下的2种硅橡胶软衬拉伸强度没有影响。

Effect of Thermocycling on Tensile Bonding Strength of Two Silicon Soft Denture Liners

Objective： To investigate the effect of thermocycling on the tensile bond strength of two silicone denture liners solidified by different way.Methods： Sofreliner MS polyvinyl siloxane soft denture liner and Silagum automix comfort soft relining were investigated.Thirty specimens of each material were made by processing the denture liner against two α-RESIN polymerdizd PMMA blocks.Each material had six specimens stored in water at 37℃ for 24 hours as the control group.The other specimens were thermocycled for 5 000,10 000,20 000,30 000 cycles.All specimens were placed under tension until failure in a universal testing machine and the fracture mode was observed with stereomicroscope.Results： There had no significant differences of tensile bond strength between each group of Sofreliner MS and Silagum（P0.05）.The tensile bond strength of each group of heat-curing silicone liner material tested in this study was higher than each group of the self-curing silicone liner material tested（P0.05）.Conclusion： Thermocycled for 30 000 cycles,the tensile bond strength of the two silicon soft denture liners we choose had no change.