Is there anyway I can increase the gap between my crowns to ease flossing?

Q. I\’d like to know if it\’s possible to very slightly increase the gap between my extremely tight fitting crowns, without having to take them out? I find it very difficult to floss, and have tried various techniques/floss. My hygienist & dentist both recommend Superfloss. However, this too is very difficult to use. Before my accident, my teeth had a usable gap between them. Now with the crowns, it\’s really difficult – to the point where I don\’t bother most days. All of my other natural teeth are fine, with a nice small gap and are easily flossed. I\’m wondering if there\’s some sort of very thin, fine gauge product akin to \’sandpaper\’, that could be used to very carefully just increase the gap by a few thousandths of a mil – just enough to make it possible to comfortably get the floss between my crowns? My dentist keeps saying just push it through and let it snap in to place. But this usually makes my gums bleed – hence my reluctance. I’m sure that if the crowns weren’t so tight that I’d be able to floss more easily, and therefore more regularly.,