Oooh - I've got one for you:
A mate has been under a fair bit of stress at work recently, and has been grinding his teeth at night as a result. The grinding has resulted in him breaking a couple of his teeth, requiring a fairly massive amount of dental work (root canal plus being fitted for a gumshield to wear at night). It's cost him a few hundred pounds so far. The company he works for doesn't offer a heath plan, but is he entitled to claim the money for the treatment back in any way?