Abstract: Abstract：　Objective　 To study the effects of different liquid immersion on the tensile strength of silicone rubber soft lining materials. Methods　 A total of 54 experimental specimens were prepared by bonding Vertex thermosetting resin base material with Molloplst B thermal silicone rubber soft lining material (group A) and Up & Up self-setting silicone rubber soft lining material (group B) respectively. A1-9, B1-9 were used in each group with 6 specimens, A1B1 group as experimental control group, no treatment; A2-5 and B2-5 were soaked in 37 ℃ constant temperature artificial saliva for 1d, 7d, 30d and 90d, A6-9 and B6-9 were immersed in denture cleaner at room temperature for 1 day, 7 days, 30 days and 90 days, respectively. The tensile strength of all specimens was tested and the fracture surface was observed. Results　 There was no significant change in the tensile strength of the tested samples in artificial saliva soaking group (P> 0.05). The tensile strength of Up & Up self-setting specimen immersed in denture cleaner decreased at 90 days, and compared with the experimental group, the difference was statistically significant (p <0.05). The strength of the thermosetting silicone rubber soft lining material was higher than that of the self-coagulated silicone rubber soft lining material (P <0.01) Conclusions　Artificial tacil soaking has no significant effect on the strength of silicone rubber soft lining material. Denture cleaner soaking 90d makes Up & Up self-shearing silicone rubber soft lining tensile strength reduced. The tensile strength of thermosetting silicone rubber soft lining material is higher than silicone rubber soft lining material.

Key words: Key words：　silicone rubber, soft lining, tensile strength