I work in an ER and see people coming in on a weekly basis for tooth abscesses. Note that these MUST be dealt with or the infection can spread - even into the brain. (I can't pull teeth - never trained and don't have the tools). These usually result from untreated cavities.

Dentists in my city charge about $250 to pull an abscessed tooth. This is beyond what many can afford. Thus these people are on a merry go round of antibiotics and pain meds. In the ER every 10 days or so. Each visit costs the system about $700. Treatment for a brain abscess would easily run into the tens of thousands of dollars.

Most of these rotten teeth are due to a history of neglect and lack of basic dental care.

I believe that universal dental (no cosmetic procedures need be covered) is the best answer.