Simple Ways to Prevent External Discoloration of Teeth

Enamel is the tough mineralized, outer structure of teeth. It is semi-transparent and the color it reflects can vary in shades of white from yellow to gray.

The change in color of enamel due to a combination of habit, hygiene and certain circumstances is classified under extrinsic or external discoloration.

Why and how does external discoloration happen?

External discoloration can range in shade from hues of yellow to black. Causative factors have been classified as non-metallic and metallic stains.

Non-metallic stains

When exposed to pigmented foods and bacteria, extrinsic stains, non-metallic in nature are absorbed into enamel.

Plaque, which is essentially colorless, then starts to exhibit stains.

Yellowish brown stains

Poor dental hygiene can turn plaque into hardened tartar and the shades can vary from yellow to darker shades of brown and black.

Examples of food that cause staining are coffee, tea, red wine, colas, cranberry juice, colored popsicles, soy sauce, vinegar, tomato sauce, blueberries, beetroots etc.

Chlorhexidine is a content of mouthwash that has antibacterial effects. It is latches on to enamel, interacts with plaque and bacteria, which colored foods make worse to end up staining.

There are other antiseptic mouth rinses that cause staining but to a lesser extent.

Black stains

These stubborn dark brown or black stains are caused by smoking tobacco. When tobacco is smoked, nicotine and tar settle on to enamel. Nicotine when oxidized infiltrates into cracks turning into a blackish tinge.

These persistent black stains are more common in women with good oral hygiene and are visible near the edge of the gums and teeth.

Called ‘black line stain’ they form on both primary and permanent teeth. They are caused by gram-positive bacteria that exhibit a certain color.

Orange stains

Orange stains are usually visible near the gum line. Children are mostly prone to orange stains, usually because of improper or irregular brushing.

Greenish – yellow stains

Stains of these colors are usually seen in children due to an interaction of existing plaque, pigmented food and bacteria and decayed hemoglobin deposits.

The causes are multiple from contact with to copper, nickel and mercury to the presence of colored bacteria.

Metallic stains

Occupational hazards that cause an exposure metallic compounds and intake of medicines containing metallic elements cause array of stains.


Liquid forms of iron supplements are a dark reddish-brown in color and can leave stains on teeth that appear black.

Violet – black

Potassium permanganate in mouth rinses deposits stains of a violet to black color.


Orange stains are common in workers exposed to colored fumes.

Yellow – brown

Medicines that contain sulfides or manganese leave gray – to yellow – to brownish black stains.


Green stains are a consequence of using mouth rinses with copper salts. Theses stains are also a result of occupational demands of workers who are exposed to copper.



Pigmented deposits from food and bacteria can cause enamel to stain. Some factors Prevention would include regular oral hygiene practices that would help prevent

1. Oral care

Oral care can prevent furthering the problem in cases due to occupational exposure, certain disease and pre dispositions.

Regular brushing and flossing at least twice a day, possibly after every meal; using appropriate toothpaste helps to prevent enamel staining and plaque from turning into tartar.

Toothpaste containing anti-staining and teeth-whitening contents has the ability to mask stains.

Regular visits to the dentist, at least twice yearly would prevent stains from spreading. An in – office teeth cleaning and polishing would enable a speedy removal of stains in people susceptible due to unavoidable circumstances.

Mouthwashes containing chlorhexidine should be used over a shorter period. Mouthwash in general should be diluted and not used frequently.

Choose fillings made of composite resin or porcelain as silver amalgam fillings leave dark stains.

2. Diet, medication and habits

To preserve the natural white of teeth and protect enamel, it’s advisable to stick to light-colored fruit juice or better still solid fruit.

Crunchy fruits and vegetables help wipe by increasing the production of saliva, which can clean plaque and bacteria on enamel.

  • Apples, pears, celery, carrots etc. are good options.
  • Sodas and fruit juices can be sipped on with a straw so they don’t affect enamel.
  • Acidic, sticky, sugary and pigmented foods should not linger in the mouth for long.

Studies suggest that chewing sugarless gum after a meal can whiten teeth and eliminate bacteria, which can accelerate staining.

Foods that can stain the tongue can stain teeth as well. Indulging in colored foods should be done so sparingly.

Contents in curries can stain and if left to stay, will cause nasty stains. Consequently, a thorough water rinse after a curry is needed.

A water rinse protocol should follow consumption of beetroots, berries, ketchups and sauces. Studies have proven that milk added to tea and coffee can decrease the staining effect of tannins.

Casein in milk is responsible for preventing staining of enamel and it’s effects are comparable to teeth whitening treatments. Ending a meal with a glass of milk or a piece of cheese can neutralize acids in the mouth and supply teeth whitening benefits.

Darker-colored teas should be avoided and in its place, green and herbal teas should be on the menu. They don’t stain teeth and a high content of polyphenols deliver protective benefits.

Vinegars can erode enamel making it more vulnerable to staining and balsamic vinegar in particular being dark in color has staining capacity.

Diluting these vinegars with water lowers their acidic and staining potential.

Iron benefits enamel by forming a protective buffer. Green vegetables contain iron and have the ability to prevent stains.

Vegetables like broccoli, lettuce and spinach especially have protective potential. Thus adding these greens to salads with vinegars can protect teeth from damaging effects.

If a liquid iron supplement is necessary, diluting it in a few ounces of juice or water can help prevent stains from forming.

Smoking is definitely a habit that causes damage and discoloration. If teeth and health in general are a priority, smoking should be avoided.


External staining although being an aesthetic concern points at an underlying problem.

Moreover, extrinsic discolorations that are neglected and lived with for a long time may become intrinsic, affecting dentin.

Once that happens treatment could get more complicated and making it hard to rescue tooth structure. Professional help that is timely to prevent further discoloration and rectify the damage can prove effective.

However, regular and responsible home care and prevention can effectively deliver results.