Teeth turn yellow for two reasons, both of which tend to accelerate with age:
The outer layer of teeth consists of enamel, which is colored almost white and protects the deeper tooth structure. Beneath the enamel is a layer of tissue called dentin, which is yellow-brown. When the enamel layer thins or wears away, the teeth begin to look darker.
Acidic foods, gum disease, and aging can wear down tooth enamel. Some people also have enamel that is naturally thinner.
Specific foods and beverages, such as coffee, can stain the teeth. Some foods that stain the teeth may also wear down enamel, increasing the yellowing.
Other sources of stains include smoking and tobacco products and certain types of antibiotics.
The following strategies may help to whiten teeth:
Eliminating foods that mark the teeth can prevent further staining. Foods and beverages that contain tannins, such as wine and tea, can stain the teeth. Coffee and dark sodas and juices can also stain them.
Acidic foods can make the teeth look yellow by wearing down the enamel. People who are concerned about the color of their teeth should avoid the excessive consumption of citrus, coffee, and soda. Alternatively, they should always brush their teeth after having them.
Dentists generally recommend waiting 30 minutes after eating before brushing the teeth. Acids can weaken the enamel, so brushing too soon can cause damage.
Quitting smoking or tobacco products can reduce the risk of nicotine stains. It can also prevent tooth decay and gum disease, both of which can damage the enamel and cause oral health issues.
Oil pulling is the term for washing the mouth with oil to remove dirt, bacteria, and debris. It is not a substitute for regular brushing or flossing, but some research suggests that washing the mouth with certain oils may help to whiten the teeth.
The American Dental Association (ADA) consider oil pulling to be unconventional dentistry, stating, "there are no reliable scientific studies to show that oil pulling reduces cavities, whitens teeth, or improves oral health and well-being."
To try this method, rinse the mouth with oil for a minute after brushing, then spit it out.
Oils suitable for oil pulling include: coconut oil, sunflower oil, sesame oil
Baking soda can gently polish away stains on the surface of the teeth. Some people worry that baking soda is too harsh and may grind away enamel, but research from 2017 found it to be a safe way to remove stains.
Baking soda may also help to fight bacteria, which suggests that it may be able to reduce plaque and prevent tooth decay.
Hydrogen peroxide is a mild bleach that can help to whiten stained teeth. For optimal whitening, a person can try brushing with a mix of baking soda and hydrogen peroxide for 1–2 minutes twice a day for a week. They should only do this occasionally.
Hydrogen peroxide may increase tooth sensitivity, so it is not suitable for long-term use or for people who already have sensitive teeth.
Apple cider vinegar has been used for centuries as a disinfectant and natural cleaning product.
Acetic acid, which is the main active ingredient in apple cider vinegar, effectively kills bacteria. The antibacterial property of vinegar is what makes it useful for cleaning your mouth and whitening your teeth.
One study performed on cow teeth found that apple cider vinegar does have a bleaching effect on teeth. However, they also found that vinegar may soften the teeth.
The acetic acid in vinegar has the potential to erode the enamel on your teeth. For this reason, you should not use apple cider vinegar every day. You should also limit the amount of time that apple cider vinegar is in contact with your teeth.
To use it as a mouthwash, dilute it with water and swish it around in your mouth for several minutes. Make sure to rinse your mouth with plain water afterwards.
Papaya fruit contains an enzyme that may help to whiten teeth.
Papain and bromelain, which are enzymes that occur in papayas and pineapples respectively, may both help to whiten teeth.
A 2012 study found preliminary evidence that solutions containing these ingredients could offer modest whitening effects. However, the authors of the study caution that more research is necessary to determine whether or not these enzymes are effective.
Maintaining excellent oral hygiene is the most important thing that a person can do to reduce tooth yellowing.
Regular brushing and flossing protects the enamel, prevents gum decay, and removes stains.
Good oral hygiene includes:
Yellow teeth are not usually the sign of a health problem, but a dentist can check for enamel loss and tooth decay.
Natural remedies can help people whiten their teeth at home. A dentist can also offer professional teeth-whitening.