The Canadian government has reversed a partial ban placed more than 13 years ago over health concerns linked to silicone breast implants.
Health Canada has granted licenses to two U.S. companies, Mentor Corp. and Inamed Corp., a unit of Allergan Inc. to market their implants in Canada, following conditional approval from the U.S. Food and Drug Administration (FDA).
Under the conditions set by Health Canada the manufacturers must continue to provide data for at least 10 years from an ongoing clinical trial and must also agree to launch another large and long-term study, involving tens of thousands of women in Canada and elsewhere, to see if there are rare side-effects that would only become apparent once large numbers of women have received the devices.
Health Canada also wants the companies to study the condition of "retrieved" implants when, at some point in the future, women have them extracted or replaced.
The manufacturers have had to agree with the conditions and develop new product labelling after holding focus group sessions with Canadian doctors and women who have the devices implanted.
In 1993 a virtual ban on the implants was imposed until new clinical studies were carried out on their safety.
This meant that only Saline-filled breast implants were generally available in Canada unless suitable alternative procedures were not available.
Health Canada's says however that consumers should be aware that the licensing of a medical device does not mean the device is risk-free, but rather that the device has the potential to provide benefits, and the risks have been reduced as much as possible.
Between 1995 and 2004, reviews in Britain and the United States have concluded there is no evidence of silicone implants causing auto-immune diseases or other systemic illnesses exists and two studies have since shown that women undergoing cosmetic breast augmentation did not appear to have an increased long-term risk of cancer, and that breast implants did not appear to directly increase mortality.
The U.S.-based National Research Center for Women and Families has repeatedly lobbied against the implants in the United States, and says Canada is making an ill-advised decision and women's health will be jeopardized.
Diana Zuckerman, speaking for the organisation, says possible silicone leaks could spread to other organs and could cost Canada's public health system millions of dollars in future.
Plastic surgeons have however applauded the decision and say the product is by far superior to the saline version.
The licensing decision followed a review by a panel of scientific experts as well as public hearings into the issue.