Round implants are filled with silicone gel that feels like natural breast tissue. In case the implant leaks, the gel remains within the implant shell or it may escape into the breast implant pocket. Leaking implants will not collapse. The implants do not rotate out of place. You will be given your implants serial number after your surgery. This is your guarantee against any manufacturing defects. These implants can last 10 years or more with proper care.