The outer solid silicone shell is the same as used in the saline-filled bag, but since they are pre-filled at the factory, no valve is necessary. These implants are filled with a silicone gel and are more natural (like normal breast tissue) in feel, touch, and consistency. They, in general, cause less rippling and are softer and more “real.” In November, 2006, after 15 years of controlled clinical trials supervised by the FDA, they found that silicone-filled breast implants were safe and effective for use in breast reconstruction and enhancement. They were released for general use in the population. Disadvantages include the need for slightly longer incisions (1-1.5 cm), more difficult to detect rupture, higher cost, and age limits (22 years of age as opposed to 18 for saline-filled).
Cohesive Gel Implant
Cohesive gel implants are silicone implants that are filled with a thicker silicone gel that holds its shape and form like a “gummy bear.” These shaped implants are designed with a focus upon a natural look and maintaining their shape in an upright position which decreases the incidence of folding of the implant shell or rippling. If you cut into a standard gel implant, the liquid silicone gel escapes from the implant shell. In contrast, when you cut into a cohesive gel implant, the implant itself maintains its shape and integrity.
The saline implant has an exterior sack made of solid silicone. Sterile saline solution, similar to that of the salt-water solution administered for intravenous fluids, is used to fill the bag at the time of surgery. For the past 15 years, this has been the most commonly-used type of breast implant. Advantages of this type of implant include the use of a natural body-filler solution in case of rupture and eventual leakage, as well as a reduced cost to the patient. Greater flexibility in filling for correction of asymmetry of breast size in the same patient is thought to be easier by some surgeons. A slightly small skin incision could be used in many patients. There are two main disadvantages of saline breast implants when compared to those filled with silicone. Because these implants are filled with a liquid (salt water), they have a higher incidence of visible and palpable ripples on their edges. They are in essence “water balloons.” They also have a significantly higher rate of deflation than the gel-filled implants. Saline-filled implants seem to work best when they are placed submuscularly, filled to manufacturer’s recommendations, and used in patients with a thicker amount of breast tissue.