The two main categories of breast implants are silicone gel or saline-filled implants. Silicone gel implants have been popular since the early 1960s, and they have gone through multiple generations of improvements since that time. Silicone gel implants have undergone rigorous studies which have shown they are safe and do not cause breast cancer nor connective tissue disorders.
The main advantage of silicone implants is that they feel more natural than saline implants. Gel implants are less prone to rippling than saline, which makes them particularly advantageous for thin patients. The current 5th generation of silicone implants are cohesive, meaning that the gel is viscous enough that even if the implant ruptures the gel tends to remain in the same place, a little like jelly. Previous generations, the silicone was more like thick maple syrup.
Saline (ie. saltwater) implants have a long record of safety too and are less expensive than silicone gel implants. They are generally placed when they are empty and filled once they are inside the breast pocket, so that the access incisions may be even smaller. When a saline implant leaks, most of the saline from the implant is rapidly and harmlessly absorbed by the body. The deflation is usually obvious, and the patient returns for removal and replacement of the saline implant. This may be done under local anaesthesia if the patient is an appropriate candidate. The primary disadvantage of saline implants is that they don’t look or feel as natural as the silicone gel implants. This is a particularly important issue for women who are thin or have decreased elasticity of their skin.