If and when I am in a position to do so, I will provide free floss and toothpaste at work. If possible, a mini locker for people to store their own toothbrushes in (with big locks- I shudder to think of the office pranks possible with public access to toothbrushes).
Businesses already subsidize all sorts of preventative health benefits such as gym memberships. Floss and toothpaste are cheap and probably would save lots of money in dental work and insurance over the long run. ¡Vivá la revolución!