1. Implant Filler: The first main difference is of course that saline implants are filled with a salt water solution while silicone implants are filled with a silicone gel. The saline implants are filled at the time of surgery with IV fluid (saline) to the appropriate volume according to the manufacturer’s recommended fill range. This does allow for some minor volume adjustments from one side to the other to compensate for small differences in breast size. In contrast silicone implants come pre-filled from the manufacturer with silicone gel. Size adjustments are not possible. Both types of implants do, however, have silicone in the implant shell.
2. Implant Feel: Silicone implants tend to be softer and have a more “natural” or “realistic” feel than saline implants. Saline implants although soft, tend to feel a little more like a water balloon.
3. Implant Appearance: Because they are filled with saline, saline implants tend maintain their rounded shape more. Often this can be noticed because of a characteristic round curve and round fullness to the upper breast. Silicone implants in contrast are filled with a silicone gel that moves within the implant as the forces of gravity and position change. Their shape changes somewhat to more closely match how natural breast tissues move.
4. Implant Cost: Saline implants are less expensive than silicone implants. The difference is a few hundred dollars.
5. Implant Rupture: All breast implants are mechanical devices and as such over the course of a lifetime they may leak. Fortunately, most implants sold in the U.S. carry a lifetime replacement warranty. When saline implants leak they slowly deflate over the course of a few days. The saline that was in the implants is harmlessly absorbed by the body. Typically, a woman will suspect that an implant may be getting smaller and within a few hours it may be clearly smaller. In a few days it may be nearly flat. Silicone implants are of course filled with silicone. Older implants are filled with liquid silicone while the newer gel implants are filled with a cohesive silicone gel. This gel does not flow like a liquid would. Rather the cohesive gel will maintain its shape even with a minor surface rupture. As time progresses (days, weeks or months), the rupture will enlarge and then the implant shape will begin to distort. At that point, an MRI or sometimes a mammogram or ultrasound may indicate that the implant has ruptured and requires replacement. Silicone implants generally do not deflate and flatten the same way that saline implants do.