There are two primary testing standards for breast implant testing: ISO 14607 and FDA Guidance.
The FDA Guidance Saline, Silicones Gel and Alternative Breast Implants calls for more robust fatigue testing than that described in EN ISO 14607 Non-active surgical implants -- Mammary implants -- Particular requirements.
The ISO Standard recommends a lateral shear of the implant for 2x106 cycles. This is carried out with the implant compressed between two plates at a preset thickness. The amount displacement is given as 40mm in total, the frequency is given at 3.3Hz.
However, the FDA Guidance does not advise using compression plates, but rather a shape which mimics "real life" situations more closely. Also, the compressive load should be monitored along with the displacement, one of which is constant. This system generates a curve depicting the number of cycles to failure, called an endurance load. This should be a minimum of 6.5 x 106 cycles. Additional testing should be used to establish the failure point.
MET has a complete programme for breast implant design validation which can be followed by the FDA or ISO route.
ISO 14607 - Non-active surgical implants - Mammary implants - Particular requirements.
Our test program includes:
- Shell integrity testing for elongation
- tensile set
- tear resistance
- strength of joints
- seams and seals
Injection site competence
Silicone gel cohesion
Static rupture resistance
Silicone release assessment
Incubators are set up for long-term silicone release tests with sensitive analysis of the bathing fluid in order to give confidence with regards to the long-term performance of the implants.
This is supported by our fatigue test rig, which can apply mechanical stress at 3.3Hz to nine implants at a time.