Hello,
For any case that require a material change, even if it is already in market. It has to be notified to the FDA. It is clearly mentioned in the FDA guidance document . A change or modification in the device that could significantly affect the safety or effectiveness of the device should require a new premarket notification. Changes that are not intended to significantly affect the safety or effectiveness of the device,however, should still be evaluated to determine whether the change could significantly affect device safety or effectiveness.
Please refer to the FDA document for more clear information when a material is changed how the product classification changes.
https://www.fda.gov/downloads/medicaldevices/deviceregulationandguidance/guidancedocuments/ucm514771.pdf