The purpose of this study was to evaluate the effects on a trial silicone material （KRS-C1, GC Corp.） of deposition of three kinds of stain: coffee, powdered green tea, and curry. The test pieces were immersed in water as a control and these three stains for 4 weeks. Color changes of test pieces were evaluated by colorimeter at the baseline and 4 weeks later. There was no difference of brightness or color between before and at 4 weeks in the control group. However, although there were no differences in brightness, the test pieces dipped into coffee, powdered green tea and curry became yellow-green. It is suggested that this trial product might become stained with long-term use.
