- the shell (the outside layer, sometimes called the envelope or lumen)
- the filler (inserted into the shell)
- the patch (covers the hole where the filler is inserted into the shell)
Typically the shell is made of a single layer ("single lumen"), but some implants have a double layer — a shell within a shell ("double lumen").
Silicone Shells for Both Saline and Silicone Implants
Both silicone and saline breast implants have an outer shell made of silicone-rubber material. But when someone refers to a "silicone breast implant," they mean the filler of the implant, not the shell. Thera are two types of implants:
- saline filled, silicone-rubber shell
- silicone gel-filled, silicone-rubber shell
Generally, the silicone-rubber shell is made of:
- Cured long strands of silicones
- Approximately 20 percent finely powdered silica tightly bound to the silicone polymers
- Small amounts of other materials
- Saline Filled Breast Implants
Saline implants are filled with a sterile saline solution — the same type of salt water used in general surgery and for other internal purposes.
There are several types of saline-filled breast implants. These types vary depending on whether saline is prefilled before breast surgery or is filled during surgery, and whether the volume of the implant is adjustable.
Common saline implants:
- Single lumen ("lumen" is the outside shell) — prefilled at the factory to a fixed volume. There are no valves for filling during surgery or for adjusting after surgery.
- Single lumen — filled with a fixed volume of saline during surgery through a valve. After surgery there are no adjustments to the implant volume.
- Single lumen — filled during surgery. After surgery, the volume of the implant can be adjusted by adding or extracting saline through a valve in the implant.
Silicone Gel-Filled Breast Implants
Silicone breast implants came on the market in 1962, but the FDA stopped sales of these implants in 1992 due to safety concerns. After a thorough investigation, the FDA re-approved silicone-gel filled implants in 2006.
These implants are now approved for women of all ages who need breast reconstruction and for women age 22 and older for breast augmentation. The reasoning behind the age restriction is that a woman's breast tissue is still developing into her 20s, and the powers-that-be at the FDA feel that women age 22 and older are more able to make informed, educated decisions than their younger counterparts.
The filler in silicone gel-filled breast implants is composed of silicone oil, cured large silicone, a small amount of uncured silicones and other materials. Silicone is a very safe compound and has been widely used in a number of medical applications for many decades.
There are several types of silicone-filled breast implants:
- Single lumen — prefilled by the manufacturer to a specific volume of silicone gel.
- Double lumen — the inner lumen is prefilled by the manufacturer to a specific volume of silicone gel. The outer lumen is filled during the breast augmentation procedure with a fixed volume of silicone gel using a valve in the implant.
- Double lumen — the outer lumen is prefilled at the manufacturer with a fixed volume of silicone gel, while the inner lumen is filled during the procedure through a valve in the implant. This third type allows for adjustments to the filler volume after surgery.
- The fourth type of silicone implant may appear to have no shell — looks and feels like a semi-solid rubber gel.
Source:
http://www.yourplasticsurgeryguide.com/breast-implants/implants-anatomy.htm
