Anatomy

A typical breast implant, whether silicone or saline filled, is composed of three parts: the shell or the envelope, the filler, and the patch.

The shell, also called the envelope or the lumen is almost always made up of a thick layer of a silicon-rubber material. This is the part that contains the filler. The shell may have a smooth or a textured surface, depending on the desires of the patient, the technique of the surgeon, or the shape of the implant chosen to be the most suitable for the client. Breast implants with textured surfaces are more commonly used all over the world, partially because of an FDA study which showed that the use of textured breast implants reduced the risk for a capsular contracture, a condition where the muscles around the implant shorten and tighten inward, squeezing the implant.

The filler, on the other hand, can either be made up of silicone or saline. Silicone is a synthetic plastic that comes in a fluid, gel, or a solid, rubber-like form. Silicone breast implants have been in use since the 1960's because they offered a firmer consistency which closely resembled the consistency of natural breast tissue. Another type of filler is saline, which is basically a liquid which has the same components as the liquid present in the human body. Saline implants are more flexible and may be smooth or textured. They may also vary in volume and shell thickness. Saline implants are the most commonly-used implants in the US.

Saline implants are filled by the surgeon at the time of the surgery, although prefilled saline implants are also available. However, there are no prefilled saline implants which are approved by the FDA at this time. A rupture in saline implants is considered less dangerous than a rupture of silicone-filled implants, since the spilled liquid can easily be absorbed by the body.

Lastly, the patch covers the opening where the silicone was inserted into the shell. Saline implants come with a valve, which are a permanent fixture in all inflatable implants. The three types of valves are the leaf valve, the kink valve and the diaphragm valve. The leaf valve has a high degree of user trauma, which is why most manufacturers no longer use this type of valve in their implants. Valves are usually found on the front portion of the implant.