A breast implant is a sac ( implant shell ) of silicone elastomer (rubber). Saline, also called saltwater, is injected into the implant through a tube during surgery.
Breast implant shells have either a smooth or textured surface. Textured surfaces were originally developed in the hope that hard capsules would be less likely to form around them compared to the smooth surface of a breast implant. There appears to be no difference, however, in the likelihood of developing a hard capsule around either one of these implants.
Textured implants may be more easily felt or recognized than smooth implants. Smooth implants are less likely to be felt through the skin and tissue of the breast. Factors such as implant placement (subglandular implants are more palpable than submuscular), implant size (larger implants are generally more palpable), and the amount of skin/tissue coverage also influence how palpable an implant is.
Depending on the desired breast shape you wish to achieve, you may choose a round or a contoured (teardrop) implant shape. Generally, round implants provide more fullness in the top of the breast compared with similar sized contoured implants. Contoured implants are designed to offer a more anatomical shape. You should be aware that contoured implants placed submuscularly may assume a round shape after implantation.