The Food and Drug Administration's approval of silicone gel-filled breast implants offers a new choice for women considering cosmetic surgery to enhance their breasts (breast augmentation). Until now, only breast implants filled with salt water (saline) were available to women desiring breast augmentation.

Silicone gel-filled breast implants — once commonly used for breast augmentation — were banned from the market in 1992. Claims linking the gel-filled breast implants to autoimmune and connective tissue diseases led the Food and Drug Administration (FDA) to institute the ban on silicone gel-filled breast implants until sufficient safety data could be compiled.

But now the FDA supports the safety of silicone gel-filled breast implants for women undergoing breast augmentation. So if you're considering this cosmetic surgery, you now have a choice between saline-filled and silicone gel-filled breast implants. How do you choose? Your doctor can help. So can being fully informed about your choices. Here Craig Johnson, M.D., a plastic surgeon at Mayo Clinic in Rochester, Minn., explains some of the differences between these two types of breast implants.

Silicone gel-filled breast implants are available to women of any age for breast reconstruction or women age 22 and older for breast augmentation. This includes primary surgery to put breast implants into place and also revision surgery to correct or improve prior implant placement.

Why the age restriction on silicone gel-filled implants for breast augmentation? One reason is because a woman's breast tissue continues to develop into her early 20s. But the age restriction is a bit arbitrary. FDA officials selected an age at which they felt women could make a fully informed decision about getting breast implants.

Saline-filled breast implants are available for women of any age for breast reconstruction. Like their silicone gel-filled counterparts, saline-filled breast implants carry an age restriction for use in breast augmentation. But in this case, you have to be at least age 18, not 22, to get saline-filled breast implants for breast augmentation.

FDA officials say the age restrictions for saline-filled and silicone gel-filled breast implants differ because the two types of breast implants carry different risks.

Each type of breast implant is filled with a different material. Saline-filled breast implants consist of a silicone shell that's either pre-filled with saline or filled with saline at the time of implant surgery. Silicone gel implants also consist of a silicone outer shell, but they're filled with a silicone gel rather than saline.

Silicone gel has a viscosity — a thick, sticky fluid consistency — that closely mimics human fat, which is a large component of female breast tissue. Saline, on the other hand, isn't compressible and gives a more firm impression.

Some women claim that silicone gel-filled breast implants look and feel more like natural breast tissue. Saline-filled implants have been criticized for feeling hard or unnatural — although changes to surgical techniques for placing saline-filled implants have minimized these complaints.

If you're thinking about getting breast implants, it's important to become fully informed about what it means to have breast implants. Before you make your decision, consider the following:

• Breast implants aren't lifelong devices. Odds are you'll eventually need additional surgery to replace or remove your breast implants. The operation to exchange old implants for new ones is relatively straightforward and requires less recovery time than does the initial surgery.
• Changes to your breasts can't be undone once you get breast implants. You might experience wrinkling, dimpling, puckering or other cosmetic changes to your breasts as a result of getting breast implants.
• Screening for breast cancer with routine mammograms may be more challenging. Additional images offering special views of your breast are often necessary. The images also may be harder to interpret because cancers can be obscured by the implant itself. You might have to visit a specialized facility experienced in mammography for women with breast implants. Your doctor might also recommend additional imaging tests — such as ultrasound or magnetic resonance imaging (MRI) — to check for signs of breast cancer.
• Breast implants sometimes interfere with a woman's ability to breast-feed. You may experience decreased milk production or you may not produce any milk at all.

Both saline-filled and silicone gel-filled breast implants have risks, including:

• Implant rupture
• Need for additional breast surgery
• Scar tissue that hardens around and distorts the breast implant (capsular contracture)
• Breast pain
• Decreased nipple or breast sensation

If you have saline-filled implants, implant deflation may be a concern. If you have silicone gel-filled implants, a rupture could mean that silicone gel leaks outside of the implant's silicone shell into the pocket where the implant was placed. However, there's no evidence that such free gel poses any threats — which is one of the reasons the FDA re-approved the use of silicone gel-filled implants.

If your breast implants are saline-filled, a rupture will likely be obvious. Your breast implant will become deflated, changing in size and shape as the saline solution leaks outside the shell of the implant.

With silicone gel-filled implants, a rupture may cause subtle changes in the size, shape or contour of your breast. Your surgeon may notice signs of a rupture during a physical exam. However, you run the risk of a "silent rupture." When this happens, you might not have any signs that the implant has ruptured. If the question of a failed implant is raised, the best way to detect it is through an MRI.

Women who get silicone gel-filled breast implants are encouraged to have regular MRI exams to check for signs of implant rupture — the first MRI three years after implant surgery and then a follow-up MRI every two years after that. Another point to consider: The cost of MRI screening may not be covered by insurance.

If your implant ruptures, you'll need surgery to remove the ruptured implant. This is a fairly straightforward procedure, which can be done through the small incisions made during your initial surgery.

The FDA is requiring the two companies that manufacture the approved breast implants to conduct extensive follow-up studies. Over a 10-year period, each company will conduct a large-scale post-approval study comparing the silicone gel-filled implants with saline implants. Investigators will look for evidence of continued safety and effectiveness of these products.

Platinum is used in the silicone shell and the gel filling for silicone gel-filled breast implants. Based on the available evidence, the FDA considers the platinum in these breast implants safe. The agency will continue to monitor these products for safety.

Another type of silicone gel-filled breast implant — called a "gummy bear" implant — is in development. The gummy bear implant consists of a more cohesive silicone gel, which helps the implant better keep its shape over time. Currently, these breast implants are available only to women enrolled in clinical studies to test the product's safety and effectiveness. If these implants make it through the clinical trial phase, they could one day be available to other women.

If you're thinking about getting breast implants, be sure to consult a board-certified plastic surgeon. Get both verbal and printed information on saline-filled and silicone gel-filled breast implants. Based on your body type, your surgeon may recommend one type of implant over another for optimal cosmetic results. Either type of breast implant is safe, but ultimately the decision is up to you.