Health authorities in the US have lifted a 14-year-long ban on silicone breast implants.
Research has concluded that silicone is not a cancer risk
Despite lingering safety concerns, two firms will be allowed to sell implants to women reconstructing or enlarging their breasts.
Each company will be required to study the effect of the implants on 40,000 women for 10 years.
Silicone breast implants were banned for most American women in 1992 after complaints that the devices leaked.
There were accusations that leaking silicone made some women ill.
But the Food and Drug Administration said independent studies had found no evidence that silicone implants caused cancer or other diseases.
However, it said there was still a risk of complications such as breast pain and implant rupture.
Patients and surgeons who advocate silicone breast implants say they look and feel more natural than those filled with salt water.
But since 1992 they have only been available to women through research programmes.
Concerns over the potential lifespan of the implants still lingers though, with the FDA warning that many silicone implants will eventually need to be removed or replaced.
"It's a hugely positive piece of news for plastic surgeons and for patients... 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," Dr Scott Spear, head of plastic surgery at Georgetown University Hospital told the Associated Press.