I'm currently of the opinion that most of the seemingly unrelated health correlations with dental health have more to do with income and just generally taking care of yourself on a daily basis.
That is, if you have money to pay the dentist, and you're also keeping up with brushing and flossing every day, you probably also can afford other healthcare, and tend to make other health conscious choices.
That said, the bacterial angle in this article is food for thought as well!