According to the Journal of Clinical Dentistry, some work a lot better than others. Researchers compared: a 0.45 percent stannous fluoride toothpaste, an anti-tartar toothpaste (containing 0.243 percent sodium fluoride and 5 percent pyrophosphate), an anti-microbial toothpaste (containing 0.24 percent sodium fluoride and 0.30 percent triclosan/copolymer), and bottled water as the control group.
Since bad breath usually comes from sulfur-producing bacteria gathered on the back of the tongue and on the teeth, the researchers measured the test users' sulfur levels daily.
After five days, all the toothpaste users agreed that regular brushing made their mouths seem fresher. But only those using the stannous fluoride toothpaste actually had better breath.