High-Strength Silicone Gel Breast Implants

Posted June 08, 2012 in Breast Augmentation, Breast Implant Options, Home, Uncategorized

The next generation of breast implants is still searching for its generic name. They have been called cohesive gels, gummy bears, highly-cohesive gels, form-stable, memory-gels and the latest entry is, high-strength silicone gel. Whatever the final name, the main difference between these new silicone gel breast implants, and their predecessors is the stuff inside. While “new stuff inside” already sounds like marketing, it’s not very descriptive when compared to the current terminology. Let me see if I can explain how we got here.

Sientra High-Strength Silicone Gel Breast Implant

The "New Stuff Inside" is Sientra's High-Strength Silicone Gel.
Left - Implant is cut in half. Since the gel does not flow, there is no leaking.
Center - Pressure on the shell causes the gel to evert, but it still acts like a solid.
Right - Pressure is released and the implant returns to its original shape. Still no leaking.

Cohesive Silicone Gel Breast Implants

When the concept first hit the market they were termed cohesive silicone gel breast implants, with emphasis on the cohesive gel. Most silicone gel breast implants have two components: a solid outer shell, and a soft center.

The Breast Implant Shell

In the most basic terms, the shell of a breast implant is designed to contain the filler. The shell of saline filled breast implants and silicone gel filled breast implants are very similar. Both are made of tough, yet flexible, silicone elastomers. The main difference being that saline breast implant shells have a valve built into them to allow the plastic surgeon to fill them during surgery. Silicone gel filled breast implants are filled and sealed at the factory, so no valve is necessary.

Breast Implant Fillers

There are currently two FDA approved fillers for breast implants in the United States: Saline and Silicone. Until recently, the terms saline implants and silicone implants were the only two terms we needed to describe a woman’s options for breast implants.

Saline Breast Implants

The saline in saline breast implants has not changed. It remains a sterile, physiologic solution of 0.9% NaCl in water. This is ideal as it is about the same saltiness as our bodies. Under normal circumstances, the saline stays inside the implant. However, saline was chosen as a safe filler just in case a leak develops.

Saline is used intravenously to hydrate us in cases where we are unable to drink. The same saline is used, right out of the IV bag to fill breast implants. The fill volume can be adjusted during the surgery. If the saline ever leaks, it simply hydrates the body. The additional fluid is quickly absorbed and circulates just like we drank it. There is no reaction to saline, but unfortunately, the implant deflates and will need to be replaced.

Silicone Breast Implants

Silicone breast implants are filled with silicone gel, a clear viscous fluid. The modern medical grade silicone gel used to fill breast implants does not flow like water, but is still classified as a liquid. New silicone filled breast implants are more like solids in that they can be made in specific shapes and will hold these shapes. This is the property that makes them unique, and this is where the generic name games begin.

Cohesive Silicone Gel Breast Implants

The first attempt at differentiating the new breast implants was to add the word cohesive in front of silicone gel breast implants. Cohesive means to adhere or stick together, which describes the way the gel resists flow and even though soft, lacks the ability to flow associated with liquids. It was an excellent choice except for one thing. All silicone gel is cohesive, even liquid forms of silicone tends to stick to itself. Instead of this term being reserved for the next generation breast implants, every company making silicone breast implants started emphasizing that silicone is cohesive.

Highly-Cohesive Silicone Gel Breast Implants

The next attempt was to add the word highly in front of cohesive silicone gel breast implants. The point being that the gel in highly cohesive silicone gel breast implants was more than just sticky. It stuck together like a solid. Again, a good word, but hard to strictly apply to only the new breast implants without confusion.

Gummy Bear Breast Implants

Derived from the analogy of slicing a Gummi-Bear candy, the new implants have also been dubbed Gummy Bear Breast Implants. The implants are soft, like fresh Gummi-Bears, and when cut in half, they act like solids. It is a good analogy, because the comparison is familiar. While people do not have experience with gummy bear breast implants, most do have experience with Gummi-Bear candy. The term has proliferated on the Internet; however, the manufacturers do not like it. Probably, this is because their lawyers tell them they can’t use it. Instead, each manufacturer has come up with their own term that describes the Gummi-Bear phenomenon.

Form-Stable Silicone Breast Implants

I first heard the term Form-Stable Silicone Breast Implants in association with Allergan’s 410 series. The term form-stable is used to describe the ability of the breast implant to maintain its shape. Unlike liquid filled implants, form-stable breast implants resist being deformed. If a form-stable breast implant is compressed, it will change shape; however, when the pressure is released, the implant returns to it original form. An extreme example of this is illustrated above. Even without the shell, the contents of a form-stable breast implant will return to its original shape.

Memory Gel Breast Implants

Mentor markets their entire line of silicone breast implants as Memory Gel Breast Implants. This includes the original, more liquid like, silicone gel filled implants, as well as their contour profile gel (CPG) models. The idea being that the implants have memory. Not the type of memory associated with what happened during summer vacation, but the engineering term of shape memory associated with plastic deformation. Essentially, it’s the same thing as form-stable.

High-Strength Silicone Gel Breast Implants

The new kid on the block, Sientra, is taking a swing at it with the term High-Strength Silicone Gel Breast Implants. The emphasis here is not so much on shape, although they were the first US manufacturer to get FDA approval for their shaped breast implants. The emphasis is on the strength of the bonds inside the silicone that allow the gel to maintain its shape. The pictures above illustrate what happens to even the most severely damaged breast implant when it is compressed. The gel is liquid enough to deform to pressure, but it high strength silicone gel has memory, making it form-stable.

What’s in a Name?

In the words of Gertrude Stein, “A rose is a rose is a rose.” When is comes to breast implants, however, many names apply. If you are considering Breast Augmentation, it is important to understand these differences. While terms like form-stable, memory-gel, highly cohesive and high-strength silicone gel are helpful, gummy bear is still the most accessible word for most people.

Maybe you have a better word to describe these new breast implants? Hopefully, after reading this you have a better feel for what we Plastic Surgeons are saying. If you have questions about gummy-bear breast implants, be certain to tune in to KRON4 at 11:00 AM on Monday, June 11, 2012, for my live show and call in with your questions. I can also be reached at my office for consultations at (925) 943-6353.