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:

Annex B:

• Shell integrity testing for elongation
• tensile set
• tear resistance
• strength of joints
• seams and seals

Annex C:

Valve competence

Annex C:

Injection site competence

Annex D:

Silicone gel cohesion

Annex E:

Impact resistance

Annex E:

Static rupture resistance

Annex H: 

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.