The refurbished point confused me. Does that mean they refurbish your own old one? If so, I would think that would alleviate most people's cootie fears. And if

The refurbished point confused me. Does that mean they refurbish your own old one? If so, I would think that would alleviate most people's cootie fears. And if it's someone else's, how does that work? I thought they had to be custom created for each person's mouth.