There is no set number of expected uses. During internal testing, opening the ring to 10mm between the tips and placing on a typical molar, the ring provides proper separating pressure for hundreds of cycles. Your use will vary depending on how far you open the rings to place them and if you're properly cleaning, sterilizing, and storing them between uses. However, Strata-G is our longest lasting matrix ring due to the combination of the PEEK backing and Nitinol wire.