On July twenty-eight 2005, the FDA ended a 13 year ban on silicone-gel breast implants and issued a letter of approval to Mentor Corp allowing the reintroduction of these controversial implants into the medical marketplace. This move came about as Mentor Corp. persuaded the FDA that its newer silicone implants are less dangerous and even more durable than older versions. The company will employ these implants only under the following strict safety conditions approved per FDA guidelines.

- Prospective patients must sign a consent form acknowledging that they realize the risks of a silicone breast implant including the fact that they may break and require replacement or even removal.

- Mentor is only allowed to sell silicone breast implants to board-certified plastic surgeons that complete a successful practical training program to learn how to insert these implants in a way that minimizes the odds of tears and breakage.

- Mentor must make and maintain a registry to track the implant patient's long term results.

- Patients must be educated about the fact that if an implant breaks, the effect of the breakage occasionally does not cause immediate symptoms. Further, patients are advised to have an MRI after five years and two years thereafter to check for breakage.

- Mentor must conduct a 10 year study to determine the percentage of breast implants that will break in that time.

- The implant study must be audited by an independent committee.

- The FDA will review the results of the Mentor breast implant program in five years to verify that the implants are performing as expected.

Based on data from the American Society for Aesthetic Plastic Surgery, 334,052 breast augmentations were performed in the United States in 2004, mostly using salt water filled implants being sold without restriction. Consumer studies predict that if the silicone breast implants return to the market, 200,000 women will visit plastic surgeons to get them in the first year. Health concerns aside, silicone implants have a more "natural" appearance and consistency than the saline version, and are therefore preferred by consumers.

Silicone-gel breast implants were first introduced in 1962 and were banned in 1992 amid health fears. Research since then has shown no statistical correlation between silicone breast implants and cancer or even rare auto-immune diseases such as lupus. A select few women will swear that their health deteriorated from the moment they received their implants, however this is anecdotal evidence. When researchers do studies comparing a large group of women with implants to an equal-sized group without them, no difference between the 2 groups is observed in the number of women with tumors or autoimmune diseases.

The most common problem reported is formation of excess scar tissue around the breast implant due to a foreign-body reaction. If it's localized, it can cause traction and rippling effects in the appearance of the implant. If the scar tissue entirely encircles the implant the condition is called capsular contraction. These scars can mold the implant into an unnatural rounded shape, so that the implant patient appears to have a baseball stuck under the skin on her chest. This condition develops more frequently with smooth-walled silicone implants, though it occurs to a lesser extent with saline implants as well. Implants set behind the chest muscle have a much lower incidence of this problem. As the scar tissue tends to re-form, surgeons can every now and again break the scar tissue manually. However this is proscribed by the manufacturer, as it can break the implant and void the manufacturer's warranty. Typically, patients with breast implant contractures require follow-up surgery.

Surprisingly, the asthma drug Accolate has proven useful in preventing and even reversing capsular contraction, though months of drug treatment may be necessary.

Other possible complications include seroma (a collection of serous fluid), hematoma (blood), synmastia (breasts that pop up to be fused in the center), bottoming out (implant slides too far down the chest), double-fold (the implant's outline doesn't corresspond to the natural crease of the breast), deflation (the implant breaks), tissue necrosis (localized demise of tissue) and infection.