Gummy implants, properly known as highly cohesive silicone gel implants, represent a significant advancement in breast augmentation technology. The informal name “gummy bear” comes from the unique, solid-like consistency of the silicone gel filler material. This specialized material is highly viscous, allowing the implant to hold its form, much like the candy from which it gets its nickname. This technology offers enhanced shape retention and a more predictable aesthetic outcome compared to earlier implant generations.
The Science of Form Stability
The distinguishing characteristic of a gummy implant is its “form stability,” a property achieved through advanced material science. Form stability refers to the implant’s ability to maintain a predetermined shape, regardless of external pressure or orientation. This is accomplished by using a silicone gel with a high degree of cross-linking in its molecular structure.
Silicone is a polymer, meaning it is made of long chains of repeating chemical units. The term “cross-linking” describes the bonds that link these long chains together. In gummy implants, the increased number of cross-links creates a dense, semi-solid gel that resists flow and deformation, similar to a soft, pliable solid. This high internal cohesiveness is what makes the implant viscous enough to resist collapsing or changing shape.
This high cohesiveness is evident when the implant’s outer shell is compromised. Unlike older silicone gels that could flow and migrate, the gel in a form-stable implant remains largely intact and contained within the implant pocket. The implant’s ability to maintain its dimensions and gel distribution, even when held upright or cut, is the practical demonstration of its form-stable design.
Key Differences from Traditional Implants
Gummy implants differ substantially from both saline and traditional, less-cohesive silicone implants in their physical behavior and aesthetic profile. The most notable difference lies in their response to rupture. Saline implants, which are filled with sterile saltwater, deflate immediately if the outer shell is breached, making a rupture obvious.
Traditional silicone gel implants contain a more fluid gel that could potentially migrate into the surrounding breast tissue upon rupture. In contrast, the highly cohesive gel in a gummy implant stays together and remains in its original shape and location, even with a tear in the shell. This containment minimizes the risk of gel migrating into the breast tissue.
Aesthetically, form stability allows manufacturers to create implants with a specific anatomical shape, often referred to as a “teardrop” profile. This shape mimics the natural slope of the breast, which is fuller at the bottom and tapers toward the top. Traditional round implants, whether saline or silicone, provide fullness more equally across the breast. The firmness resulting from the cohesive gel also reduces the likelihood of visible rippling or wrinkling, which can be a concern for patients with minimal natural breast tissue coverage.
Safety and Long-Term Integrity
The unique properties of form-stable implants introduce specific safety considerations that patients and surgeons must address. Because many gummy implants have a teardrop or anatomical shape, maintaining their precise orientation is necessary to achieve the desired aesthetic result. If a teardrop-shaped implant rotates within the breast pocket, it can lead to an unnatural or distorted appearance, requiring a corrective procedure.
To mitigate the risk of rotation, these implants often feature a textured outer surface that encourages surrounding tissue to adhere to the shell, helping to lock the implant into its correct position. The cohesive nature of the gel also means that a rupture of the outer shell may not cause any noticeable symptoms, a condition known as a “silent rupture.”
Due to the risk of silent rupture, regulatory bodies recommend routine medical imaging to monitor implant integrity. For asymptomatic patients, the recommendation is to undergo a Magnetic Resonance Imaging (MRI) scan five to six years after the initial surgery and then every two to three years thereafter. Furthermore, the introduction of these devices required mandatory long-term post-market surveillance studies to continually track their safety and performance over time.