Have tried wearing a mouthguard previously about 9 years ago after seeing a fellow (he first game too!) get most of one of his front incisors snapped right off while charging a machine gun nest. However after a few games I stopped because it's a pain in the ass to talk on a radio or run around gulping down air with a guard in your mouth.
Nowadays I never wear full face protection (unless the field requires it), no problems.
I've only seen two chipped teeth in a decade of playing, like the fear of bleeders I find that the danger is overhyped compared to the real risk.