H.T.
Another mom mentioned flossing, which I know is hard for for 5 yr olds to do. My 5 yr old uses FunFlossers (A bright orange pkg, sold at Wal-mart by the tooth brushes). Anyway they're little plastic handles w/a small piece of floss string on them. My kids like using them.
Another idea that my dentist suggested for my 7 yr old (has bad breath now & then) is to use a tongue scraper. They really work. She uses it after she brushes.
Good luck!