Buttock implants come in a variety of shapes and sizes to best fit each patient's body type and desired goal. They are made of soft silicone, which provides a firm, smooth and natural feel. They are placed away from important nerves as well as the bony area on which you sit. The upper and outer regions of the butt become rounder and firmer once the implants are in place. The procedure takes about two hours and is performed under general anesthesia. Incisions are made inconspicuously in the depression between the buttocks.