The problem is that poor people need cash for lots of things. If you're poor enough that you can't go to the dentist, you're poor enough to be hurting in any number of ways. If we give you $500 and say, "now this is for the dentist -- save it in case you need it", they're quite rightly going to tell you to fuck off and go buy food and gas for the car to get to work. And then when they need a dentist six months later, we're right back where we started, except with the added shittiness of a bunch of upper middle class conservatives preaching about how they "wasted" the money.

There are actually already public dental clinics in many cases with reduced fees for people below certain income levels.

Yeah. Pretty much all the same arguments could be applied to automobile purchase and maintenance, something that many people require to get from where they live to where they work. It doesn't mean that we need to have a government program specifically to cover cars.

The margins are healthy enough that many dentists work 4 days a week while earning a fantastic living.