Analysis of Explanted Silicone/silica Composite Breast Implants

A study was conducted to examine the physical, mechanical, and chemical properties of composite (silicone/silica) breast implants as a function of implantation time. In the study the properties of SILASTCII gel-filled explants with in vivo duration times ranging from 4 months to 10 years were compared to lot-matched control (unimplanted) samples. Tensile strength properties were measured for both explant and control shells using identical testing protocols. The tensile strength properties of shells which were extracted with hexane to remove non-cross linked silicones were also measured. In addition, swelling measurements were used to determine the average molecular weight between cross-links (and/or entanglements). The tensile strength properties obtained from the present study were correlated with implantation time. The results of the study suggest that the silicone elastomer shells do not undergo appreciable degradation during in vivo aging.