Silicone gel breast implants have been available in the United States for decades – going back to a time when medical devices didn’t require approval by the Food and Drug Administration (FDA). In 1992, after evaluating existing research on the safety and efficacy of silicone implants, the FDA took them off the general use market because it found that the manufacturers had not done adequate research to show that the products were reasonably safe.
See also Mammography
While many things about screening mammograms are uncertain, there's at least one thing that is certain: baseline mammograms shouldn't be recommended as a routine part of health care for women. There is complete agreement about this, even among organizations that disagree on almost every other aspect of mammography.