Sientra has halted U.S. sales of breast implants made by contract manufacturer Silimed, following suspension of sales by regulators in Brazil, the U.K., and other countries.

Santa Barbara, CA-based Sientra has posted a letter to surgeons on its website, asking that they stop implanting the devices until further notice. A German audit of Silimed's Brazilian factory found unidentified particles had contaminated some manufacturing surfaces.

"We have been in ongoing discussions with the United States Food and Drug Administration (FDA) regarding this matter and out of an abundance of caution, we are voluntarily recommending that you temporarily discontinue implanting all Sientra devices manufactured by Silimed," Sientra's CEO Hani Zeini wrote in the letter to surgeons. "We are also voluntarily placing on temporary hold, the sale in the United States of all Sientra devices manufactured by Silimed, and we ask that you set aside all such devices in a secure location and not use them until further notice."

Sientra's stock fell by more than 19% to $5.65 per share on Monday, but had recovered slightly today, reaching $6.64 by noon. Sientra did not ask surgeons to remove the implants, and noted that no injuries have been reported. Zeini said the company is conducting its own review.

An audit at Brazil-based Silimed has triggered the biggest breast implant scare since the 2010 Poly Implant Prothèse (PIP) debacle, which ultimately led to the jailing of that company's CEO, the shuttering of PIP, and stricter regulatory requirements in the European Union.

Silimed, which is the biggest maker of silicone implants in South America and claims to be the third largest implant manufacturer internationally, insists on its website that its products are safe, even as it voluntarily halts product sales.

Silimed makes 5000 types of implants used for everything from general surgery to bariatric surgery. Other countries such as Switzerland, Ireland and other EU member states, Australia, and New Zealand have also suspended sales of products made by Silimed.

The company had been the first South American firm to claim that its silicone breast implants had been approved by FDA.