4 ms·How long does one last? Do you use one for a week, month or just whenever you change your toothbrush?by 83457 10y agoHow long does one last? Do you use one for a week, month or just whenever you change your toothbrush?nailer 10y agoAbout a month. The main thing is the plastic bumps on the wire wear away after a while.83457 10y agoOh nice. They are pretty cheap then. I don't floss as much as I should (or should I?) so might give these a try. Thanks