Sugar-free gum or mints? Sugar-free gum wins this one. According to the University of Michigan School of Dentistry, the chewing involved with sugar-free gum stimulates the production of saliva – and that clears away the acids that naturally form in the mouth and cause cavities. Gum also clears away leftover food stuck in your teeth – and the sugar-alcohol in sugar-free gum, namely xylitol, has an anti-microbial effect, which reduces harmful bacteria that can damage teeth and make your breath stink. Sugar-free mints can have a similar effect – but you’d need to get really strong ones to produce more saliva. But because they dissolve quickly, they don’t do as much good as gum.