Variability in the properties of silicone gel breast implants

Several generations of silicone gel breast implants have been produced by i mplant manufacturers. The primary material usually viewed as the base mater ial in the manufacture of implants is polydimethylsiloxane. Polymeric react ions are notorious for their variability and nonuniformity. The elastomer u sed in different types of implants can have vastly different properties. Fu rthermore, the material properties associated with a particular type of imp lant can vary considerably from one lot to the next. Considering the variou s designs, styles, and manufacturing techniques associated with silicone ge l implants, knowledge of the original properties of the implants before imp lantation is important in determining the effects of aging in vivo. This st udy was conducted to investigate differences in key mechanical and chemical properties of silicone gel breast implant materials. The two types of impl ants chosen for analysis were Silastic I and Silastic Il control implants. Material property data were determined for both types of controls and signi ficant differences were found in their values. Lot-to-lot variability was a lso investigated and found to be significant.