What is the Difference Between Saline and Silicone Gel Implants?

Saline and silicone gel are very different filler materials with different properties. Saline is called a non-coherent filler. A non-coherent filler does not resist a change in shape, whereas a coherent filler like silicone gel does resist a change in shape. In other words, if saline is placed into a round container and suddenly that container changes shape to square, the saline will quickly flow and assume the square shape. Not so with silicone. It will stay round, at least for a while, until it slowly moves to take the new shape of the square container.

Implants are silicone shells filled with either saline (salt water) or silicone gel (approved by the FDA November, 2006). There are two primary types of fillers used in breast implants: saline filled and silicone gel filled implants. Saline implants have a silicone shell filled with sterile saline (salt water) liquid. Silicone gel implants have a silicone shell filled with a viscous (cohesive) silicone gel. Saline implants are firmer than silicone gel implants. Silicone gel implants better resemble the texture and feel of natural breast tissue. Not all silicone gel implants are the same. Silicone can vary in its physical properties. Some implants are softer than others. Some are firmer, but hold their shape better (“Gummy” implants). You can read more about the different implants types here. Not every woman is a candidate for this type of implant. Both implant types are very safe, and each offers its own specific advantages. I will help you decide which kind is right for you.

Saline Implants

I want to get this one out of the way. Saline implants are very firm, far more so than silicone gel. Saline implants have far more rippling associated with them than do silicone gel filled implants. Some people request them because they believe that they are more “natural.”  Saline implants have a silicone shell (envelope, bag) just like all silicone gel filled implants do, so what is so natural about that? The next thing I hear from those requesting them is that they are “safer.” If a saline implant gets a leak, or ruptures, it is true that the saline will be absorbed by your body and you will excrete it. Your breast will deflate in a couple of days. Now, the soft tissue envelope (your breast) will begin to contract against this empty space so it is advisable to fill it with another implant fairly soon (a few weeks) before the breast contracts so much that it will be difficult to produce a similar appearing breast with a replacement implant, even of the same style and size as the implant you had prior to rupture.

These same people then express concern that if a silicone gel implant leaks, the gel will travel all over your body. The reality is that is not the case at all. Here is why: Whenever a foreign body such as a pacemaker, artificial joint, or breast implant is inserted into your body, the body responds to it by creating a scar tissue capsule around the foreign body, much like an oyster creates a pearl around a piece of sand placed inside. The scar capsule typically forms around a breast implant in about three weeks. Should a silicone gel filled implant rupture, and the gel comes out of the implant shell, this gel will remain trapped inside the pre-existing scar tissue capsule. The gel has no opportunity to travel anywhere. Silicone is inert anyway, which means that it will not react nor cause harm to the body and vice-versa. Lastly, at surgery, any silicone gel that is loose in the implant pocket is actually very easy to remove.

Another disadvantage of saline implants is that saline implants have a valve used to fill them during surgery (they arrive deflated from the manufacturer), which is another potential point of failure (leakage) not found in silicone gel implants, which arrive pre-filled from the manufacturer. My own personal feeling about them – in the vast majority of cases, breasts augmented with saline implants just do not feel natural. The exception would be a young person with at least a full B cup to start with good quality tissue. In these cases, saline implants will often produce a satisfactory result, but still never feel as soft and natural as the breast would with a silicone gel filled implant. And, think about this – as the breast ages, maybe following pregnancy and breast feeding, the breast tissues now atrophies. That same saline implant that gave an acceptable result will now not look and feel so natural anymore. So, you need to think about the future as well when selecting an implant. Am I biased towards silicone gel implants – absolutely. Having performed thousands of breast augmentations, I believe that there is no comparison between saline and silicone implants. That is why both my daughters have silicone gel implants, not saline. This is just my opinion, but I have a vast amount of patients who will agree with me.

The Ideal structured implant available that is filled with saline but has a series of baffles inside – like a series of implant shells one surrounding another. This reminds me of the Russian Matryoshka doll. It has not one, but two valves (double the point of failure). The purpose of the baffles is to control the flow of saline inside the implant to give it a similar feel to that of a silicone implant, but without any concern for loose silicone if ruptured. While this implant is superior in feel to that of a conventional saline implant, I do not find it to be as close to silicone as perhaps its manufacturer would like me to think it is. This implant only comes in one variety, and therefore there is no ability to customize the implant characteristics to the specific breast tissue characteristics and patient preferences like one can do with silicone gel implant. While I am sure you can achieve a reasonable result with this implant, I do not believe (my opinion here) that the results will be the same as with a silicone gel implant.

So, in summary, in my humble opinion, considering today’s choices in silicone gel implants, I do not believe that saline filled implants are optimal for anyone except a person who wants implants but is petrified of having a silicone gel filled implant inside their body. And that is an unjustified fear, but then again, you can only educate someone to try to resolve their issues. Should those fears persist, I know of no way to make them disappear. That is my only indication for a saline implant – unjustified fear of silicone.

Silicone implants

Silicone gel-filled implants provide a much more natural feel to the breast, and are the implant choice for the vast majority (99%) of my patients. In November 2006, after fifteen years of intensive study by many researchers, the U.S. Food and Drug Administration (FDA) had re-approved silicone breast implants for breast augmentation surgery. I am proud to offer patients the option of silicone gel-filled breast implants, since they yield a much softer and more natural feeling breast than when saline-filled breast implants are chosen.

A silicone implant feels much closer to human breast tissue, whereas a saline implant is firmer than breast tissue. Due to the cohesive nature of silicone gel, such an implant has far less rippling and wrinkling than does a saline implant. This is especially important for women with thin tissue, as irregularities in the implant contour will be painfully obvious with respect to the look and feel of the augmented breast. Remember this important concept for later: the more tissue you can put in front of an implant, the less visible and palpable the implant will be.

With the recent July 2019 recall of textured surface breast implants (both saline and silicone gel filled), the only silicone gel filled implants (Allergan Natrelle) available are round, smooth implants. What about teardrop shaped smooth implants? No such thing. The textured surface anchors the implant to the surrounding tissues and prevents movement of the implant within the breast implant pocket. Without such adherence, the teardrop implant would rotate within the pocket, making your breast continually change shape – not a very desirable thing! If a round implant rotates, and it will, the shape of the breast remains constant. You will not even be aware of the implant rotating, if it should do so.

OK, so now we have round smooth implants? What is the variety? Well, there are several parameters to consider, even among a single manufacturer’s portfolio of implants. I like the Allergan Natrelle line of implants. I have used others, and they are all good, but I have used the Allergan implants since 1994. Allergan Natrelle offers the greatest amount of implant options when you consider size, profile, and gel type. They have the most options of gel type (three). More on that in the topic Silicone Gel Breast Implants – Options.

With currently available choices of breast implants in the United States, there is a trade-off. There are two important characteristics that patients in particular pay attention to. The first is softness and the second is shape. The ability for an implant to hold its shape when placed in the vertical position (which is the position the implant will be when you are upright) is called “form stability”. Softer implants tend to possess less form stability, and those implants with greater form stability tend to be firmer. With three choices of gels, you can have one that is very soft but with poor form stability, one that is firm but has excellent form stability, or one in-between. There is no “best” implant here. There are times that I prefer one of these over the other two. Sometimes I feel a patient will do best with one of the three choices, and sometimes I believe that any of the three will give great results. It all depends upon the patients preferences and their tissues and breast architecture. The article  Silicone Breast Implants: What You Need To Know will dispel some of the myths about silicone gel implants.

A Word About Silicone and Safety

In 1991, due to unfounded concerns that silicone breast implants were responsible for certain autoimmune diseases such as rheumatoid arthritis, lupus and scleroderma, the FDA director, David Kessler, MD (a pediatrician), created a moratorium on silicone breast implants pending further study. What this meant was that silicone gel filled breast implants would not be available in the United States for general use in women except under special organized multicenter investigational studies. The use of these implants did continue, however, in other parts of the world. In November, 2006, the FDA gave clearance to the use of silicone gel filled implants. Silicone breast implants became the most studied medical devices in history. The results of these studies concluded that silicone breast implants are safe and are not related to breast cancer or connective tissue disorders.

The best information regarding the safety of breast implants is obtained from epidemiological studies between two groups of women who have and do not have implants. With this type of study, one can then draw an accurate conclusion as to whether certain disease processes occur more frequently in those women with (or without) implants. These studies are much more scientifically meaningful in terms of drawing an accurate conclusion than case reports of individual or small groups of women.

The best summary of these studies that I am aware of can be found in Appendix 2 and Appendix 3 of The Best Breast 2, written by John and Terrye Tebbetts, where the key epidemiological studies are individually summarized by Dr. Tebbetts. (Dr. Tebbetts is my mentor who in 1994 taught me the principles and technique of performing a breast augmentation with a 24 hour recovery). I encourage you to read his book and familiarize with the concepts presented – this way we will be “on the same page” at consultation time. These epidemiological studies conclude the following:

• There is no connection between breast implants and breast cancer.
• Women with breast implants who do get breast cancer are not delayed in their diagnosis of breast cancer and are not diagnosed at a further stage of breast cancer than women without implants.
• There is no proven connection between breast implants and connective tissue disorders such as lupus and scleroderma.

There is an association between textured surface implants (both saline and silicone gel filled) and a rare, low grade malignancy called Anaplastic Large Cell Lymphoma (ALCL). This is not breast cancer, but rather an easily curable, low grade malignancy of the natural scar tissue that forms around every breast implant or implantable device inside the body. At this point, I am NOT using textured implants; I only use smooth surface implants, so this is not a concern. You can read more about ALCL here.

There is also an entity called Breast Implant Illness (BII). I call it an “entity”, because its existence has not been proven. There are some women with breast implants who believe that their implants are responsible for chronic fatigue, headaches and other vague symptoms. To date, I have not seen a single patient that I was convinced had BII. You can read more about BII here.