messed up piece that sink aerator screws into

Hey all,

I was replacing my sink aerator and managed to get the aerator out after struggling with it for a while. But as I was doing it I somehow dented the piece of metal that my new aerator is supposed to screw into. Now my new aerator wont fit into the metal because it's dented inwards on both sides from the pliers clamping on it.

What can I do to un-dent this? I've tried using pliers to open it back into a circle but it wont budge.

If I have to replace it, what do I have to do and what is that piece called?

Thanks!

If you can't straighten it out your looking at replacing the entire faucet.