A Food and Drug Administration report released Wednesday showed that silicone-gel-filled breast implants are safe, as the agency defended its 2006 decision to put them back on the market. But the longer a woman keeps them, the more likely she will experience complications. One in five women getting breast augmentation had to have them removed within 10 years. Silicone was banned in 1992 in response to fears of a possible relationship between the breast implants and cancer and various autoimmune diseases, such as lupus. When the FDA decided to put the silicone-gel-filled implant back on the market in 2006, consumer groups were outraged.