Simply Breast Implants breast augmentation

Cohesive Silicone Gel Breast Implants

All About Cohesive Gel Implants

How have silicone gel breast implants changed over the years?

The first silicone gel implants (developed in the early 60's) had a seamed rubber shell with a very thick silicone gel filler. They were anatomical in shape and very firm compared to the silicone gel breast implants on the market today.

In the 1970's, breast implants were redesigned. The shells of these implants were much thinner, contained no seams, and the silicone gel filler was much thinner. There were problems with these implants as well. Because the shells were so much thinner, they were much more prone to rupture. In addition, the thin shells allowed silicone to seep through the shell. During one of my office visits to my plastic surgeon, Dr. Tom DeWire, I had the opportunity to hold one of these older generation silicone breast implants. I specifically remember him telling me to "be careful" with it. I can only assume that he was concerned that rough handling would result in the implant rupturing. The thin shell was very apparent as I held it in my hands, and the implant itself felt greasy and slimy, presumably from the amount of silicone bleeding through the shell.


Ruptured Silicone Gel Breast Implant

Custom “piggyback” Georgiade Surgitek implant (placed 1978), consisting of a smaller (100 mL) anterior contoured single-lumen silicone gel-filled implant (in a state of uncollapsed rupture) (thick arrow), shown here maintaining its original contoured shape, attached directly to a larger (185 mL) posterior single-lumen silicone gel-filled implant, shown here ruptured with the attached fragments of its shell laid out symmetrically (thin arrows).1


The 1980's were the dawn of yet a newer generation of silicone breast implants. Manufacturers made thicker shells which rendered the implants more durable and did a much better job of controlling gel bleed through the shell.

In the 90's, shells were again made thicker, and the silicone gel used inside the implants was even more cohesive.

Today, all silicone is cohesive, meaning that even if the shell ruptures, the silicone will not spill out. The video below shows how the newer silicone gel implants. When cut into, the gel stays in in the shell and does not spill out. This is not a gummy bear breast implant, which is even more cohesive.


What are the differences in silicone gel cohesiveness?

All silicone is cohesive, with the most cohesive being high-strength silicone implants, commonly referred to as gummy bear implants. However, the lesser cohesive silicone gel implants of today are sill cohesive, though not to the same degree as high strength. Still, when cut in half, the silicone gel does not spill out of the implant. Those days are long gone.

Mentor breast implants have three grades of cohesiveness that applies to their silicone gel breast implants.

Cohesive I™ The standard cohesive level gel used in Mentor® Breast Implants. This is the softest gel.

Cohesive II™ A slightly firmer gel for surgeons wanting a firmer feeling implant.

Cohesive III™ Mentor's most cohesive gel, providing shape retention with a pleasing level of firmness for optimal aesthetic results. This gel is used in Mentor® MemoryShape™ silicone gel breast implants.

Natrelle® has their own levels of cohesiveness as follows.

Natrelle® TruForm™ 1 have a round shape and are filled with the softest cohesive gel.

Natrelle® TruForm™ 2 and 3(previously referred to as Highly Cohesive Soft Touch and Highly Cohesive" are either round or shaped and are filled with a highly cohesive (firmer) gel. Natrelle® TruForm™ 2 and 3 implants are considered form stable as there is no migration of the gel, allowing the implant to retain its shape. The TruForm™ 3 gel is used in "gummy bear" breast implants.

The video below shows a "regular" (non-gummy bear silicone implant) cut in half with a scalpel. As you can see, the gel does not spill out.

Don't cohesive silicone breast implants require longer incisions?

Yes, slightly longer incisions are necessary for all types of silicone breast implants, but with the use of the Keller Funnel, incisions are now able to be made shorter then previously thought. Unlike saline breast implants, which are inflatable, silicone implants cannot be rolled up, inserted into the pocket, and then filled with silicone gel. Since all silicone gel breast implants are prefilled, they require a slightly longer incision, particularly when the Keller Funnel is not used.

Don't cohesive silicone gel breast implants have a higher rate of capsular contracture?

Years ago, silicone breast implants definitely had higher capsular contracture rates than saline breast implants, which many surgeons and researchers believe was largely due to the amount of gel bleed older generations of silicone implants. Gel bleed isn't nearly as much of an issue as it was decades ago.

One thing that does put one at risk for capsular contracture with silicone implants is the insertion of the implant. Because the implant has to be "worked" into the pocket (see video below), there is more chance of bacteria and/or skin particles (flakes) entering the pocket. This can cause an inflammatory reaction in the pocket, which can lead to capsular contracture.