Frederick Kipping, an early investigator of silicone-oxygen compounds, mistakenly believed that the molecules he synthesized contained a silicon-oxygen double bond analogous to the carbon–oxygen double bond found in ketones.  Hence the name silicone was given to this family of compounds.

The term silicone is still widely used today.  We hear it used to describe materials such as elastomers, gels, fluids, and more.  The common feature in these materials is that they contain linear polymers comprised of repeating units of silicon and oxygen. These polymers are identified broadly as polysiloxanes.  Today polysiloxane polymers form the backbone of silicone materials used in the medical device industry. 

Silicone elastomers are crosslinked polysiloxanes which have been reinforced with fillers such as silicon dioxide.  Gels are unreinforced polysiloxanes which are crosslinked to varying degrees.  Silicone fluids are simply nonfunctional polysiloxanes. 

Despite the misnomer, I will use the term silicones when referring to polysiloxane-containing materials used today in the medical device industry.