silastic

As a proper noun Silastic

is a type of flexible, inert silicone rubber, used especially in prosthetic medicine to make devices such as shunts to control hydrocephalus, artificial heart valves and breast implants.

As a noun silicone is

any of a class of inert, semi-inorganic polymeric compounds (polysiloxanes), that have a wide range of thermal stability and extreme water repellence, used in a very wide range of industrial applications, and in prosthetic replacements for body parts.

As a proper noun Silastic

is a type of flexible, inert silicone rubber, used especially in prosthetic medicine to make devices such as shunts to control hydrocephalus, artificial heart valves and breast implants.

As a noun silicon is

a nonmetallic element (symbol Si) with an atomic number of 14 and atomic weight of 28.0855.