The following information describes the differences between round saline-filled and round silicone gel-filled breast implants.
Saline: A saline implant is filled with a salt water solution which is very close to the saline content naturally found in the human body.
Silicone: A silicone implant is filled with a safe moderately cohesive silicone gel that has been used in over 10 million women worldwide.
How is the Breast Implant Filled?
Saline: A saline implant is filled, by the operating surgeon, through a valve in the anterior surface of the implant. After the implant is filled, the valve is sealed with a small cover.
Silicone: The manufacturer fills a silicone gel implant. A patch cover, fused to the implant shell, is used to seal the posterior surface of the implant where it was filled.
Breast Implant Volume
Saline: Every saline implant must be filled to its specified minimum volume, but there is a volume range above this minimum that the manufacturer deems appropriate. For example, the minimum volume for a 300cc saline breast implant is 300cc; the recommended volume range may be 300cc – 325cc. The operating surgeon can choose to fill the implant to a volume within this range, or may sometimes choose to fill (overfill) the implant to a volume above this range. A saline implant provides more flexibility in terms of variable sizing.
Silicone: Each silicone implant exists as a specific volume and it is not adjustable. The manufacturer fills a 300cc silicone gel implant with 300cc of gel.
Let’s say a patient requires a 300cc on the right and 325cc on the left to achieve symmetry. If a saline implant is chosen, the surgeon could use the same size saline implant on both sides and just fill the right implant with 300cc and the left implant with 325cc. If a silicone gel implant is chosen, the surgeon would select a 300cc implant for the right side and a 325cc implant for the left side.
What Incision Length is Required?
Saline: A saline implant can be placed through the smallest incision because the implant is placed into the pocket when it is empty, and then filled once inside.
Silicone: Since the silicone gel implant is prefilled, it must be placed through a larger incision. An emphasis is also placed on using a larger incision to prevent unnecessary damage to the implant when it is being inserted.
Where Can the Incision be Made?
Saline: A saline implant can be placed through one of four incisions: periareolar, inframammary, axillary, and umbilical.
Silicone: A silicone gel implant can be placed through two (or three) incisions: periareolar and inframammary; some surgeons may choose to use an enlarged axillary incision. A silicone gel implant cannot be placed through a transumbilical approach.
Breast Implant Feel and Firmness
Saline: A saline breast implant feels less like natural breast tissue due to the liquid filling. If a saline implant is overfilled, the consistency (firmness) of the implant increases. Therefore, the feel and consistency of the saline implant will always depend upon the final fill volume.
Silicone: Silicone gel implants have a very consistent feel. The silicone gel implant feels softer and more natural than a saline implant; and the cohesive silicone gel implants feels more like natural breast tissue. In addition, because each silicone gel implant is filled in a similar fashion, the consistency and feel of the implants does not vary from size to size.
Breast Implant Rippling
Saline: Saline has an inherent tendency to cause rippling and wrinkling of the implant shell, which is often palpable beneath the tissues. In patients with less tissue covering (e.g. thin skin, minimal subcutaneous fat, and minimal breast tissue), a saline implant can be quite palpable, and might even be visible at times. Some wrinkling and rippling of the implant shell is palpable in almost every woman who has a saline implant. Although such rippling is frequently present, that does not mean that the rippling is problematic or bothersome. However, most women prefer not to have obvious rippling in their implants.
Silicone: Although the shell of a silicone gel implant does wrinkle and ripple, the thicker consistency of the gel matrix makes the ripples and wrinkles less palpable through the tissues. In many cases, women who have problematic rippling of their saline implants would likely be happier with silicone gel implants.
Breast Implant Interaction with the Breast Tissue
Saline: The saline solution is more likely to produce a “water hammer” interaction with the over lying tissues of the breast. A water (fluid) hammer is a pressure wave or surge that occurs when a fluid in motion is forced to stop or change direction suddenly. This may have a less than natural feel, and may place additional biomechanical stress on the breast-skin envelope.
Silicone: Silicone gel implants, have a more gentle interaction with the breast tissue. This can produce a softer more natural feel and may place less biomechanical stress on the breast-skin envelope.
Breast Implant Pocket Location
Saline: Since saline implants have a greater tendency to ripple, and because they often have a firmer consistency, they should be placed only a subpectoral pocket to maximize tissue covering and camouflage of the implant.
Silicone: Silicone gel implants are soft enough to be able to be placed in a subglandular or subpectoral position.
What Happens When a Breast Implant Fails?
Saline: When a saline implant fails, the saline solution leaks from the implant and is reabsorbed by the capsular tissue around the implant. The volume inside the breast therefore decreases, and the breast shrinks in size as the implant deflates. Saline implant failures are usually evident within a few days after the failure occurs.
Silicone: When a silicone gel implant fails, the thick cohesive gel does not rapidly escape from the implant. Any gel that does leak from the implant is not absorbed, and remains within the space between the implant shell and the capsule surrounding the implant. As a result, the volume inside the breast remains unchanged and the breast size remains stable. Since the breast size does not shrink, a gel implant failure may go unrecognized. The term “silent failure” has been used to describe a silicone gel failure.
How Does the Breast Implant Look on an X-ray?
Saline: Saline implants tend to be radiolucent. This means that x-rays penetrate the saline implant fairly easily, and they appear somewhat translucent on an x-ray film.
Silicone: Silicone gel implants are rather radiopaque. This means that x-rays do not travel easily through the implants, and they appear rather white on x-ray film.
The radiolucency of breast implants is not really clinically significant. The goal of mammography is to displace the breast tissue from over the implant so it can visualize without any implant overlap. Because of its radiopacity, extracapsular silicone gel migration can be seen on a plain xray.
Breast Implants are FDA Approved
Saline: Saline breast implants were FDA approved in 2000 for use in women 18 years of age or older. They may, however, be used in women of any age for breast reconstruction
Silicone: Silicone gel breast implants were approved in November 2006 for use in women 22 years of age or older. They may, however, be used in women of any age for breast reconstruction