Evolving the Saline Implant
Saline-filled breast implants were initially developed as a tissue expander. It was later realised that this saline-filled device could also be used as an implant itself. This effectively made it a direct alternative to the silicone implant.
The advantage of saline implants is that they can be inserted through a smaller incision. This is because the volume can be adjusted during surgery to fine-tune any volume asymmetry a patient has.
A disadvantage, however, is they felt more like a water balloon in comparison to the silicone breast implant which was more viscous and more like natural breast tissue. However, in patients with sufficient soft tissue coverage over the implants, the difference between saline and silicone implants was minimal.
The body of each Implant is built as a two-component prosthetic, filled either with saline or silicone gel. They are surrounded by a layer called the “shell” which in essence is a solid silicone form that protects the core of the silicone gel implant. To clarify, silicone gel is a mixture of semi-inorganic polymeric molecules. In other words, it feels and looks like an oily fluid. To give an example, you can see silicone in the lubricants they use with most medical devices.
Evolving the Silicone Implant
The first generation of silicone-filled implants were teardrop shaped. They had several Dacron fixation patches to help maintain their proper position and avoid movement or spinning.
The main problem experienced with these original breast implants was a relatively high contracture rate. This was believed to be due to the quality of both the shells and the gel. As a result, the second-generation silicone implants were developed in the 1970s.
The second generation implant had a thinner, seamless shell, no Dacron patches and were filled with a less viscous silicone gel for a more natural feel. Their general design was also changed from a shaped to a round implant. Unfortunately, these thinner shells led to complications, namely, there were leaks and ruptures throughout the breast. This was because of the thinner shell and lower viscosity of the silicone gel itself.
Thus in the 1980’s, the third generation of silicone implants was developed. These implants focused on increasing the strength of the implant shell, decreasing its permeability to silicone molecules, and to reduce the risk of implant rupture.
This was done by altering the shell into a multi-layered silicone elastomer. With every generation, they came up with new solutions to fix the problems that arose in the last. The 4th and 5th generation are what we see being used today as the standard for breast enhancements.