The current generation of silicone breast implants is more advanced than other previous silicone implants. Whereas older silicone implants may have been filled with a liquid silicone that could slowly leak out of a rupture in the implant shell in fashion similar to molasses, the newer silicone implants are filled with a cohesive silicone gel. This cohesive silicone tends not to flow out like a liquid but actually tends to stay within the shell even when the shell has a defect. In fact, one manufacturer has a photograph of their silicone implant that has been cut in half. This photograph shows the cut half of the implant with the cohesive silicone still within the half in a fashion similar to gelatin.
It may therefor be more difficult to determine if there is a rupture or leak in the shell of a silicone implant. The FDA recommends an MRI at 3 years to evaluate the implant, however, unless the implant coincidentally has a rupture at that time, this study will not provide lifetime information about whether the implant is intact.
More likely is that when a woman is performing her monthly self breast exam, she may feel that there is an abnormal change in the feel of the implant and/or its shell. If that is the case then an examination by her plastic surgeon followed by a mammogram, ultrasound or MRI as necessary may be necessary to determine if the implant has ruptured. A small rent in the surface of the implant may not be detectable by physical examination alone until it enlarges.