Saline vs. Silicone – Similarities
Both saline and silicone implants are approved by the FDA for breast augmentation. Both are available in a wide variety of sizes and shapes, and both are available with either a rough or smooth surface texture.
Both saline and silicone gel implants have the same outer shell made of solid silicone plastic. The shell itself has not been a source of controversy. Silicone in all forms, from liquid to solid, is one of the most biologically inert substances known. The filler material used in silicone implants today is a cohesive gel that has a jello-like consistency compared to the viscous liquid form used in earlier generation implants (Figure 10 – legend: A current generation silicone implant that is cut in half shows that the filler material is a semi-solid).
Both implant types are safe. Although there have been claims in the past that there is a relationship between silicone gel filler material and certain rare connective tissue disorders, this has never been proven. The latest studies continue to refute this notion. In fact, the Institute of Medicine, a Washington agency, has concluded long ago that silicone implants do not cause any disease. Their findings have been published in an informative brochure called Information for Women about the Safety of Silicone Breast Implants. A copy can be obtained from the National Academies Press at 800-624-6242 or online at www.nap.edu. Another website that addresses the safety of implants and has other useful information is www.breastimplantsafety.org. Additional information is available from the implant manufacturers at www.mentorcorp.com and www.allergan.com.
Saline and silicone implants of the same size and shape will look exactly the same once implanted. There is no difference between the implant types in this regard. This is an extremely important point to emphasize because many are under the mistaken notion that silicone looks more natural.
Both implant types eventually need to be surgically replaced, usually after ten years or so. This means that multiple replacements will be necessary over one’s lifetime, with more in women who are very young at the time of the initial procedure.
Neither type of implant imposes any restrictions on activity once healing is complete.
Saline vs. Silicone – Differences
The advantages of saline implants are that they do not contain silicone gel and do not require any special tests for long term monitoring. A disadvantage is they are sometimes easier to feel on the side and bottom of the breasts, most commonly in very thin women with scant amounts of breast tissue to begin with. They may also cause visible wrinkles in this same type of individual. Also, saline implants can deflate prematurely after only a few years in about 5 percent, a harmless but inconvenient event that requires implant replacement.
The key advantage of silicone implants is that they feel more natural to the touch, sometimes being completely undetectable due to the nature of the filler material. The main disadvantage is that they require special tests such as an MRI scan in order to monitor shell integrity as the years pass. These scans are not typically covered by insurance.
Older model implants with a liquid silicone filler have rarely been associated with migration of microscopic amounts of silicone into the lymph nodes in the armpit. This does not cause health problems but may require a surgical biopsy to confirm the benign nature of the condition. Silicone implants now filled with cohesive gel are presumed less likely to develop this problem as they age.
Silicone implants usually require a slightly larger incision for insertion. The armpit incision option is generally not possible with silicone implants. Empty saline implants can be easily passed prior to inflation through the narrow channel that lies between this incision and the breast whereas prefilled silicone implants cannot.
Saline implants seem to have a better prospect for lasting beyond ten years compared to silicone implants. Clinical experience has shown that saline implants can last as long as twenty years or more with no change in the aesthetics or consistency of the breasts whereas silicone implants have more of a tendency to develop capsular contracture (breast hardening - see below) or silent rupture as they age beyond ten years.
Saline implants cost less than silicone implants. However, there are additional charges in the case of premature deflations that make them more expensive overall should that occur.
Silicone implants do not completely prevent wrinkles in very thin women with scant amounts of breast tissue. Sometimes they can also exhibit wrinkles, although the tendency is far less than with saline implants. Occasionally silicone implants can exhibit a conspicuous bump or knuckle due to an implant fold, something which does not occur with saline implants. A summary of difference between the two types of implants is shown in the Table.
Round vs. Shaped Implants
There are many implant shapes available today for both saline and silicone implants. These are grouped into two broad categories: round and shaped. The latter are also termed “anatomic” or “tear-drop” types. Shaped implants are commonly used in breast reconstruction after mastectomy, a quite different scenario. The vast majority of plastic surgeons today use round implants for aesthetic breast augmentation. Round implants in the upright position behave like shaped implants in that the filler material migrates to the bottom of the implant, leaving less at the top. While lying down the filler material is evenly distributed and resembles a natural breast shape in that position. A problem unique to shaped implants stems from their asymmetric shape. If they rotate inside the pocket both shape and symmetry can be adversely affected. Definitive correction requires surgery to exchange them for round implants if this occurs. Another drawback of shaped implants is that they can look unnatural when lying down because the volume is not distributed evenly. It is for these reasons that round implants are recommended as the best choice for breast augmentation.
Smooth vs. Rough Surface Implants
Breast implants can have either a rough (textured) or smooth surface. Studies are only weakly suggestive that a textured surface may decrease the chance of capsular contracture. Supportive evidence for this applies primarily to implants positioned in front of the muscle, a choice associated with significant disadvantages and not widely practiced today. Textured implants, particularly saline types, tend to wrinkle more than smooth ones. Given the greater surface resistance of textured silicone implants a longer incision is often required for their insertion. Smooth implants are preferred for breast augmentation when all of these issues are taken into consideration.
Regular vs. High Profile Implants
Breast implants are available in several profiles that determine how much forward projection they have. Implants with equivalent volumes will have a smaller diameter as the profile, or projection, increases. Most patients are best served with moderate (regular) profile implants. Patients that either have a narrow chest, a small breast base diameter (or both) and seek a maximum implant volume are good candidates for a moderate-plus (intermediate height) profile implant. Moderate-plus profile implants are filled tighter than moderate profile implants of the same volume and tend to wrinkle less as a result. They are therefore also a good choice in very thin patients with little breast tissue. High profile implants have a very round, bullet shape and are rarely used.