Strawberries: They may stain your shirt, but they may work to whiten teeth because they contain an enzyme called malic acid. Try crushing strawberries and applying them to your teeth. Leave it on for five minutes, then rinse with water and brush and floss as usual.

Apples, Celery, and Carrots: These healthy fruits and vegetables act as natural stain removers by increasing the production of saliva, which acts as the mouth's self-cleaning agent. They can also kill bacteria that cause bad breath, and their crunch factor helps clean teeth by brushing them.

“A 2008 study found that toothpastes containing baking soda, long considered a home teeth-whitening remedy, did a better job of removing plaque than toothpastes that did not contain the ingredient.”

Oranges and Pineapples: Eating sour fruits like oranges and pineapples can cause the mouth to produce more saliva, which naturally keeps teeth clean. Be careful not to rub lemon directly on your teeth, as too much acid can damage teeth.