The government ended a 14-year virtual ban on silicone-gel breast implants Friday despite lingering safety concerns, making the devices available to tens of thousands of women who have clamored for them.

The Food and Drug Administration approved the silicone-gel implants made by Inamed Corp., now part of Allergan Inc., and Mentor Corp., the two California companies said.

FDA planned a teleconference later Friday to announce a new product approval.

The action opens the implants to much wider use by women seeking to reconstruct or augment their breasts. Since 1992, the silicone implants had been available only as part of research studies.

Silicone-gel breast implants first went on the market in 1962, before the FDA required proof that all medical devices be safe and effective. Thirty years later, they were banned amid misgivings about their safety.

At the time, there were worries about a possible connection to a variety of diseases, including cancer and lupus. Alarming cases of ruptures added to the concern.

Since then, most studies have failed to find a link between silicone breast implants and disease.

The rupture issue persists: The implants do not last a lifetime, and eventually they must be removed or replaced, according to the FDA. A 2000 Institute of Medicine report found rupture rates as high as 77 percent.

Women whose silicone implants ruptured have reported years of pain, swelling, numbness and other symptoms that they blame on the devices. Leaked silicone gel can migrate throughout the body and form lumps. Implants also can cause infection and form hard, painful scar tissue that can distort the shape of a breast.

Some researchers also worry that platinum used to manufacture the implants can seep into the body and cause harm. The FDA says there is no evidence of that.

Proponents say silicone-gel implants look and feel more natural than do those filled with saline, or salt water. Those implants are sold without restrictions.

"It's a hugely positive piece of news for plastic surgeons and for patients and for the company — all three — because it really allows us to turn a page and to work with what we have believed for a long time is a better technology and better device," said Dr. Scott Spear, head of plastic surgery at Georgetown University Hospital and an Allergan consultant.

Last year, the FDA told both companies their implants could be approved once they met additional, undisclosed conditions. For Inamed, the decision went against a panel of advisers who narrowly recommended that the company's implants not receive FDA approval. They cited concerns about the long-term durability of the implants. The same advisers endorsed Mentor's implants.

In October 2003, FDA advisers recommended allowing implants to be sold again. The agency then overruled the recommendation.

Breast implants have grown in popularity for augmentation, despite their litigious history. Last year, 291,000 women had their breasts surgically enlarged in the United States, a 37 percent increase since 2000, according to the American Society of Plastic Surgeons.

The popularity of implants for reconstructive surgery shrank over the same five-year period by 29 percent, to 58,000 procedures, according to Society statistics. Last year, 39,000 women had their implants removed.

Overall, the use of breast implants has grown hugely since 1992, when the FDA instituted its de facto ban on silicone-gel implants.

Just three years later, Dow Corning Corp., once the major manufacturer of silicone breast and other implants, faced 19,000 lawsuits, forcing it into Chapter 11 bankruptcy in 1995. The company emerged from Chapter 11 in 2004, after setting aside $2.35 billion to settle claims.

"This is by far the most defective medical device ever approved by the FDA," said Dr. Sidney Wolfe, of Public Citizen. In 1988, the consumer group petitioned the FDA to ban the implants.

Allergan Inc. shares rose $1.76 or 1.6 percent in trading that was almost double its average volume to close at $112.50 on the New York Stock Exchange. Mentor Corp. shares increased $1.47 or 3.19 percent in higher than average volume to close at $47.58 on the New York Stock Exchange.