The Tooth Whitener You Probably Have in Your Purse
What to try: Sugarless gum.
Why: Chewing gum causes you to produce more saliva, which is a natural buffer against stains, explains Matthew Messina, DDS, a spokesperson for the American Dental Association. When your mouth gets dry, food particles and bacteria can settle on teeth, affecting the enamel. Common causes of dry mouth are talking on the phone, medication (prescription drugs for depression, anxiety, heart problems and nerve pain; OTC meds like antihistamines and decongestants) and—ready for this?—cardio exercise. Studies have shown that when athletes run, their saliva levels decrease. In addition to chewing gum, sip water throughout the day and swish it around your mouth after eating.
The Dark Horse Whitener That We Always Underestimate
What to try: Good ol' baking soda.
Why: Physically scrubbing your teeth may actually have some effect on surface stains, says Messina. However, it's essential that the substance not be so gritty that it wears away enamel. Baking soda mixed with water is just abrasive enough, and Messina says that baking soda toothpastes that have the American Dental Association seal have been found safe to use with a soft toothbrush. (You can also try "whitening toothpastes" that have enzymes to help dissolve surface stains.)
What not to try: Brushing with sea salt, rinsing with activated charcoal (Messina says that there's zero clinical research behind it). They sound so wacky they just might work, but Messina says that these DIY don'ts could cause serious, permanent damage to your enamel.
The Last Best Hope for Deeply Stained Teeth
What to try: An in-office whitening treatment.
Why: Deep stains penetrate under the enamel and get stuck in the chicken-wire-like structure of your tooth. Professional-grade treatments use an effervescent whitening agent (a cousin of peroxide) that bubbles out the enamel and lifts the stain out of the chicken wire, explains Messina. (At-home whitening kits work the same way, but they're not nearly as powerful.) Be aware that stains aren't always due to a long-term love affair with coffee and red wine; Messina says that discoloration can also be a sign of a developmental issue, infection, receding gums (due to crowding, grinding or age) or periodontal disease. Your dentist can help get to the root causes of your stains and advise you on next steps.
What not to try: These Internet-approved fixes just don't work: pure bleach (it could burn the inside of your mouth); rinsing with lemon juice (it's an acid that can chemically dissolve enamel, Messina says); scrubbing strawberries on your teeth (they don't have any sort of magical plaque-destroying vitamins, but they do have some potent stain-producing acids and natural coloring).