Silicone breast implants are a widely used type of implant for both cosmetic and reconstructive surgery. Many plastic surgeons report that patients choose silicone consistently over saline. The most commonly mentioned difference between silicone and saline is how the implants feel to the touch. Saline is usually detectable since it has a very different consistency than the surrounding breast tissue. In addition, the implant shell must be filled until it is quite firm to achieve the best look. In contrast, many patients find that silicone closely imitates the feel of a natural breast.
The biggest visible difference between silicone and saline is often noticeable during movement rather than at rest. Certain breast positions may cause the edges of a saline implant to become visible or make the surface ripple. Some patients are better candidates for silicone than saline. A cosmetic surgeon may recommend silicone for women with too little breast tissue, inadequate chest muscle or thin skin to help ensure that the edges of the implant are not readily visible through the skin.
Background of Silicone Implants
Silicone breast implants have been in use in the United States since their invention in the 1960s. They became a popular cosmetic enhancement in the 1980s. In 1992, the FDA restricted the use of silicone implants to clinical trials to fully evaluate the safety of the devices. After 14 years of data had been collected, the FDA re-approved the use of silicone for cosmetic surgery patients in 2006. The manufacturers are still participating in ongoing safety studies per FDA requirements. Currently, patients must be at least 22 years of age to receive a silicone implant for cosmetic augmentation (the minimum age is 18 for saline implants). This age limit may be changed in the future as more safety data is gathered regarding silicone.
About Available Silicone Implant Brands
The models used in the United States are generally the MemoryGel from Mentor and the Natrelle (previously called Inamed) from Allergan. Both implants have a similar construction with several layers of silicone elastomer enveloping the gel inside. The goal of using multiple shells is to reduce the risk of the gel bleeding through into surrounding tissue over the life of the implant or in the event of implant failure.
The implant shells are available in smooth and textured surface options. There is some evidence to suggest that the textured surface promotes better tissue adherence and reduces the risk of capsular contracture over the short term. Larger, longer term studies are needed to confirm these results and see if this purported benefit lasts throughout the life of the implant.
Silicone Filler Options
Each manufacturer has its own proprietary formula for the cohesive gel filler. Both brands have a similar weight, feel and appearance per cc of volume. There are some slight variations in implant shape due to differences in available diameter and profile (how far out the implant projects from the chest). Patients can select their preferred gel type from varying levels of cohesiveness depending on how soft they want their silicone implants to be.
Not all implant sizes and shapes are available in both cohesive I (softer) and cohesive II (firmer) types. Firmer implants require a larger incision since they can’t be compressed and manipulated as easily. The cohesive III implants are the fifth generation “gummy bear” implants that are still undergoing clinical trial testing. They are available to a few patients at this time through participating surgeons. At this time, only the cohesive III silicone implants are made in an anatomical shape similar to teardrop saline implants. All other silicone implants approved for use in the United States are round.
Silicone Implant Placement
Silicone implants can be placed either over the muscle or under the muscle. Each approach has pros and cons. Submuscular placement for silicone implants is often a longer and more complex procedure. It may cause more discomfort and require a longer recovery period. However, the implants will generally look and feel more natural in this position. Under the muscle placement is also associated with lower rates of capsular contracture and greater ease in obtaining clear mammogram images. Over the muscle placement is a faster surgery. It also provides easier access to the implant if revision is required. However, the need for revision surgery may be greater with this type of placement since a higher number of complications may arise.