After a 13-year ban, silicone-gel-filled breast implants are another step closer to returning to the market.

Following the recommendations of an advisory panel, the Food and Drug Administration (search) told Mentor Corp. on Thursday that its implants can be approved under certain conditions.

"We are very encouraged by this communication from the FDA, and view this letter as a positive sign for women and their surgeons that another option will soon be available," said Joshua H. Levine (search), president of the company based in Santa Barbara, Calif.

The implants were banned because of health concerns. But, on April 13 an FDA advisory committee voted 7-2 to recommend allowing them back on the market under certain conditions.

Among those conditions were ensuring that women understand the devices may break silently inside their bodies; recommending that women get regular MRI exams to check for such breaks; allowing only specially training plastic surgeons to perform implant insertions; and requiring new studies to prove how long implants last.

The FDA said it is not allowed to reveal the contents of its letter to Mentor (search). But the company said the conditions outlined in the letter generally are consistent with the advisory panel's recommendations.

The FDA's confirmation of its intent to approve the implants occurred even though the Senate Health, Education, Labor and Pensions Committee is investigating the advisory committee's recommendation from three months ago.

"Various complaints were made to the HELP Committee in April 2005 alleging that there were conflicts of interest among FDA advisory panel members that may have caused the panel to reach recommendations to approve Mentor's application for silicone breast implants," said committee spokesman Craig Orfield.

Also Thursday, a group of seven female senators led by Sens. Dianne Feinstein, D-Calif. and Olympia Snowe, R-Maine, urged the FDA to consider women's safety before the agency makes a final decision.

The FDA advisers voted in favor of allowing the Mentor implants back on the market just a day after turning down a request from a competitor, Inamed Corp.

Women who have sought the return of the product say silicone-gel implants look and feel more natural than the salt water-filled implants sold without restriction.

But other women told the advisory panel about silicone oozing out of their bodies and of years of pain and other symptoms, which they blame on faulty implants.

Diana Zuckerman, president of the National Research Center for Women and Families, who has argued that the devices are not proven safe, called the action "shocking."

Silicone-gel breast implants first went on the market in 1962, before the FDA required proof that all medical devices be safe and effective.

The implants largely have been exonerated of concerns that they might cause serious or chronic illnesses such as cancer or lupus. But aside from the risk of breakage, they can cause infection and painful scar tissue.

About 264,000 breast enlargements and 63,000 breast reconstructions were performed in the United States last year.