Cosmetic Surgery Blog

Currently, there are two types of breast implants approved for sale in the United States, the saline-filled implant and the silicone-filled implant. However, clinical studies on a newer type of silicone-filled implant are now underway. This implant, which contains a type of silicone that is almost solid, is called a high-strength silicone gel implant and is available only as an investigational device at this time.

Silicone-filled implants have evolved over the years, from shells filled with a silicone the consistency of thin oil to current models that are filled with a silicone gel that is described as a soft solid. These more solid implants are being called cohesive implants or high-strength gel implants. They have also been nicknamed “gummy bear” implants, because the gel filler has the consistency of the candies by that name.

Unfortunately, the word “cohesive,” which means the ability to stick together, is also being used to describe the silicone-filled implants already on the market. All silicone gel used in today’s implants is cohesive to some degree. It is not a runny liquid, but ranges from a thickness like that of egg whites to that of jelly. If they are cut, the silicone oozes a bit, but does not flow out like the saline used in saline-filled implants.

High-strength cohesive implants are thick enough to hold their shape if a piece is cut away or even if the outer shell is completely removed. To give a comparison, if the thickness in the currently approved models is the consistency of grape jelly, the newer models are the consistency of really firm Jell-O®.

Both saline and silicone implants have an outer shell of silicone elastomer, a tough, plastic-like substance. Saline implants are filled with sterile salt water, which is absorbed harmlessly by the body if the implant ruptures. When silicone-filled implants rupture, silicone is released in the anatomical pocket that contains the implant, but the rupture can go undetected for several years.

The rationale behind creating a more solid silicone-filled implant is that the contents will stay in place inside the shell even in the event that the shell is ruptured. Another benefit is that these implants should last longer and feel more natural. They also hold their shape and position better when inserted.

The disadvantage of the firmer, high-strength silicone-filled implants (gummy bear implants) is that they require slightly larger incisions for insertion, which means bigger breast augmentation scar. Usually, they are inserted through an incision under the breast (inframammary incision), but can be inserted through an incision around the areola of the nipple. A transaxillary (armpit) incision is not recommended with these breast implants. Breast augmentation surgery complications with cohesive gel implants are similar to those seen with other types of implant.

Three implant makers are conducting clinical trials of “gummy bear” implants in the United States. They are Allergan, Mentor, and Silimed. Allergan and Mentor make the two brands of saline- and silicone-filled implants that are currently approved for U.S. sales. Silimed, a Brazilian company, is the third largest maker of breast implants in the world. Although the three brands of implants are basically similar, there are differences.

At this time, the only way to get high-strength silicone gel implants (gummy bear implants) in the United States is to be enrolled in a clinical trial. To be eligible, you must be a woman who is otherwise suitable for breast augmentation. You have to agree to return to your surgeon’s office regularly for tests and other follow-up procedures, which include regular magnetic resonance imaging (MRI) and other screening tests. You may also be asked to fill out questionnaires on a regular basis and have photographs of your breasts taken.

If you are accepted into a clinical trial, you will still have to pay for your breast augmentation surgery, but some costs for follow-up visits are covered by the implant manufacturer in return for your taking part in the study. You may also be paid for each follow-up visit.

“Gummy bear” implants are probably still a few years away from being approved for sale.