Strength, strain, energy, and toughness of silicone breast implant shells

Leakage and rupture are established problems associated with aging breast implant shells. The effects of time in the body on the mechanical properties of these shells were investigated. Tensile tests were performed on 573 specimens cut from 5 new and 40 used implant shells. Correlations were observed between shell condition, implantation time, and maximum stress. Maximum strain, which is easily measured, correlated stronger with both condition and implantation time than stress did, suggesting that maximum strain can be used as a convenient and representative measure of implant durability. Fold flaws do not appear to affect the tensile strength of shell material, but are often sites for pinholes that may lead to leakage and rupture