The difference between Saline and Silicone Implants?
by Dr. Ahmed Maki on Oct 24th, 2016
Breast augmentation has been performed for over a century. During that time we have been presented with two options; silicone versus saline implants.
While silicone implants have had 4 different generations of implants created, the main changes have been to the shell of the implant and the silicone gel itself.
The silicone implant invented in 1961 by Dow Corning researchers Thomas Cronin, Frank Gerow and Tom Biggs became the foundation for the first generation of breast implants. The early devices had a seamed rubber shell filled with a viscous form of silicone gel. They were firm to the touch and had a teardrop shape. During the several years Dow Corning made these implants they refined their design, creating a thinner, seamless shell.
Next, the 2nd generation implants hit the market. The first generation implants were plagued with high capsular contracture rates and an unnatural feel. Thus, the new 2nd generation implants had a thinner shell and also a more liquid silicone consistency. These implants not only had a tendency to rupture, but also were found to leak silicone through their shells. These were the devices most often involved in the lawsuits that led to the fourteen-year ban by the FDA.
The main change to the 3rd generation implants in the 1980s was in the shell itself which was created more durable to prevent silicone leakage.
And then 1992 arrived. Overcome by hysteria of the media and a less than accurate scientific report that was released, the FDA surrendered to the pressure from a variety of groups and banned silicone implants for cosmetic usage limiting them only to reconstructive and revision patients. In late 2006, after considerable additional study, the FDA re-approved the devices for all women over the age of 22, finding no evidence that they cause disease.
During this time period, saline implants were the only available options to patients interested in cosmetic breast augmentation. Although saline implants have been generally shown to have decreased capsular contracture rates, they are fraught with multiple issues. Rippling rates were significantly higher as patients began complaining that they not only could see the implant itself but could also see the wave effect of the saline in the implant. Furthermore, saline implants had a much higher rupture/deflation rate requiring reoperation. Typically saline implants also dictated that the surgeon would need to use a sub-pectoral space under the muscle to place the implant. This placement is complicated with issues such as blunting of the implant, distortion with flexing and also probable lateralization of the implant due to the contraction of the muscle over time. Placement of an implant under the muscle tends to mimic the actual muscle itself versus breast tissue. However, with saline implants the added coverage of the muscle over the implant is often necessary to prevent the rippling issues commonly seen.
The silicone implants today can be considered modified third generation implants or 4th generation depending on the report. The key difference is the highly cohesive nature of the silicone. The gel used is a much thicker more cohesive gel substance which prevents extravasation of the silicone if there were a rupture. Often times with these implants it is necessary to perform an MRI to determine rupture due to extreme cohesive nature of the gel. This type of implant has a extremely low rupture rate ( some reports less than 2% over 10 years), and if they do rupture it is often termed a "silent rupture" where there isn't much if any distortion of the implant. This is in extreme contrast to a saline rupture which when ruptured results in complete deflation and flattening of the chest wall.
Often times people may report that with saline implants the size of the initial incision may be created smaller. This, however, should be considered of minimal consequence due to added technological devices such as the Keller Funnel which insures the smallest 3 cm incisions are created even with silicone breast augmentation. Trans-umbilical breast augmentation (TUBA) is the only current approach to breast augmentation that requires the use of a saline implant.