Another alternative is to place the implant beneath the lactiferous glandular/adipose tissue region. Commonly called, “above the muscle placement” this location yields a more pronounced effect, but can also appear less natural.
Two basic material designs exist. They are, cohesive gel implants (silicone gel in a polymer shell), and saline component in a polymer shell. Each offers distinct advantages, and patient considerations. Silicone gel implants generally have a more natural feel, but, in the past have been reported to lead to complications in some
women, if they rupture. Saline implants (salt water) don’t have the same feel as silicone (but very similar), but if ruptured for any reason they will be easily absorbed without complications. Generally, silicone implants cost a bit more as well. In construction design, anatomical implants are made in a teardrop shape, offering a natural appearance that flows
http://sexuallubricants.org/sexual-lubricants/