Whitening chewing gums
What could be easier than whitening your teeth as you chew gum? On paper, it would appear that whitening chewing gums – which contain ingredients that are abrasive or able to coat teeth to prevent stains from sticking – can get rid of extrinsic stains, but there's been very little research into the efficacy of these products. Some studies found that chewing gum with the compound sodium hexametaphosphate can prevent new surface stains from forming better than no chewing gum and placebo chewing gums. However, another study showed that certain nicotine-medicated chewing gums can remove extrinsic stains better than a whitening chewing gum.