A U.S. advisory panel on Wednesday urged approval for Mentor Corp.‘s silicone breast implants, a recommendation that could end 13-year-old restrictions sparked by concerns about the health risks when silicone leaks.

The 7-2 endorsement from the Food and Drug Administration advisory panel was a surprise following the committee’s 5-4 rejection a day earlier of Inamed Corp.‘s silicone implants.

“They’re not the same device,” said panel member Stephen Li, president of Medical Device Testing and Innovations, noting that Mentor’s implants had an “extremely low rupture rate” and impressive testing on device fatigue.

“The statistics and the follow-up were excellent, and we didn’t have nearly the questions on this application as we did on (Inamed’s),” Li said.

Mentor shares rose 12 percent in after-hours trading, while Inamed shares fell 5 percent.

The FDA will consider the panel’s input as it decides whether to approve more widespread use of silicone implants. Concerns about potential links between leaking silicone and disabling diseases prompted officials to ban the devices for most women in 1992.

The agency typically follows its panels’ advice, but 15 months ago it overruled a recommendation for approval of an earlier Inamed bid for silicone breast implants.

Final FDA approval of Mentor’s implants “is by no means a slam dunk. ... The end result won’t be known for some time,” said Amit Hazan, an analyst at SunTrust Robinson Humphrey.

If the FDA decides to approve Mentor’s application, the company should monitor some women for implant ruptures for 10 years and meet other conditions, the panel said. Also, women considering implants should get consent forms detailing what is, and what is not, known about implant risks.

Many women and plastic surgeons say silicone implants look and feel more natural than saline breast implants - the only option for most U.S. women since 1992.

Implant makers also say today’s silicone implants are more durable than older versions, and the gel is stickier and less likely to migrate.

Studies have failed to find a connection between silicone implants and Rheumatoid Arthritis, lupus and other chronic diseases that many women tie to the devices.

But panel member Brent Blumenstein said he was concerned that some women studied by Mentor reported exhaustion, joint pain and other possible symptoms of chronic diseases.

“In short, there’s too much uncertainty,” he said.

Makers admit implants can cause pain and other local complications, and they can break and require new operations to replace them. Mentor said a study of about 400 women showed 1 percent of implants broke over three years. None of the ruptures caused problems, and were detected by MRI scans. Other research showed no ruptures before seven years, Mentor said.

The ruling in favor of Mentor was a shock to rival Inamed, said Dan Cohen, Inamed’s vice president of global government and corporate affairs.

“I am stunned and amazed by the bizarre decision by a small number of panel members who yesterday demanded longer-term data and today accepted shorter-term data,” Cohen said.

Inamed’s main study followed patients for three to four years, while Mentor’s main study tracked women for two to three years.

In the United States, only breast cancer survivors and others needing reconstruction or implant replacements can now receive silicone implants, through clinical trials.

After closing up 2.2 percent to $35.33 in regular trading on the New York Stock Exchange, Mentor shares gained 12 percent to $39.45 a share on the Inet electronic brokerage.

Inamed shares, which closed down 4.4 percent at $63.51 on Nasdaq, fell 5 percent to $60.30 after hours on Inet. Inamed is being acquired by Medicis Pharmaceutical Corp.