Yes, it kills germs, plus gets rid of plaque and whitens your teeth. And the gum health thing is a huge plus! According to the book, the OOO also penetrates tooth enamel and so can stop abscesses and kill germs inside the teeth and in the gums. It's a totally fascinating book.
Like mh said, between the OOO and the tooth powder, I don't see how you could go wrong.