10 Reasons Why Your Teeth May Be Yellow

While Australians aren’t quite as fanatical about having glowing white teeth as Americans, nobody likes having a mouth full of discoloured chompers. There are a number of things that can cause your teeth to turn yellow or brown, even red, green and even black.

These factors that can change the colour of your teeth are split into two categories, extrinsic and intrinsic. Extrinsic factors are those that stain the hard surface layer of the teeth known as enamel. Extrinsic stains are most typically caused by lifestyle factors such as food, drink and smoking, and these stains are fairly easy to remove or lighten. Intrinsic stains are those that occur within the dentin, the inner structure of the tooth. These colour changes are typically caused by medications, medical treatments such as chemotherapy, ageing and damage. These stains are much harder to remove than extrinsic stains.

Food and Drink

Many foods and drinks can cause discolouration of teeth. Drinks like coffee, tea, red wine and cola, as well as foods high in pigment like cherries and chocolate are well known causes of tooth discolouration, but they are not alone. Many foods can stick to the teeth and promote the growth of bacteria that go on to cause the teeth to turn yellow or brown. Your mother may have told you that sugar and sweets will rot your teeth or turn them yellow, and while that isn’t exactly true, sugary or high starch foods (like potato chips) can stick to the teeth and promote the growth of bacteria that can and will discolour teeth.


As tobacco use is well known to be bad for your overall health, it should really come as no surprise that tobacco use will also discolour your teeth . Tar and nicotine both contain agents that stain the teeth progressively darker the longer you continue to smoke. Smoking can also cause damage to the gums and salivary glands that can in turn cause damage to the teeth leading to more discolouration. Even though tar and nicotine stains are extrinsic, they are some of the hardest to remove. 


If a number of people in your family have yellow teeth (and aren’t smokers) then you may have a genetic predisposition towards having thinner than normal enamel on your teeth. The enamel layer is white, but the dentin (the inner structure of the tooth) is yellowish. When the enamel is thin, either due to wear or generic reasons, the colour of the dentin can show through giving the teeth a yellowish colour.


Wear and tear over age can cause the enamel on your teeth to thin allowing the yellow dentin to show through. Existing stains can also darken over time making yellowing more pronounced the older you get.  Over time, the inside of the tooth (the pulp) can calcify, making the tooth appear more opaque and discoloured, this can happen more quickly if the teeth have been subject to trauma (discussed later).

Poor Oral Hygiene

Brushing after meals, flossing and rinsing can stop stains from high pigmented foods and drink from building up, but more importantly, keeping good dental hygiene is necessary to stop the buildup of plaque, a clear and sticky bacterial buildup in the mouth that can lead to a number of tooth and gum issues. Plaque that isn’t removed hardens to become tartar, a hard yellowish crust that causes discolouration. The bacteria that form both plaque and tartar excrete acid that can damage enamel, causing it to thin showing the yellow dentin or causing cavities. Poor oral hygiene can also lead to gun diseases like gingivitis and periodontitis, both of which can lead to serious tooth damage and discolouration.

If you’re not happy with the colour of your teeth. Book an appointment with your dentist now .

Some Medication

Some medications can cause discolouration of teeth. Some antibiotics - tetracycline or doxycycline - taken while pregnant or by children under 8 can cause a permanent striation or banding of teeth. Other medication can potentially stain adult teeth. These medications include some antipsychotic drugs, antihistamines, blood pressure drugs. Talk to your doctor if you have an adverse action to medication. Chemotherapy can also lead to discolouration of teeth.


Some illnesses experienced by pregnant mothers, or by children while the enamel is forming in the adult teeth can affect the appearance of these teeth. Gum diseases such as gingivitis and periodontitis can lead to tooth damage and discolouration.


Trauma caused by a fall, blow, shock or the like can cause teeth to discolour. In children, damage to the teeth can cause issues with the development of enamel. Trauma to the teeth can also lead to bleeding in the internal area of the tooth - the pulp chamber. The blood can clot and those clots, along with decomposing damaged pulp tissue can get into the tubules of the dentin. These microscopic channels that run through the dentin from the pulp to the under layer of the enamel become stained by the blood and tissue causing the tooth to change colour. In adults this colouring can be quite dramatic like brown or black, but in children the staining can be more yellowish. 

Excess Fluoride 

While a small amount of fluoride can be good for your teeth, excess consumption of fluoride can cause your teeth to be stained yellow. Fluoride staining is mostly seen in children who swallow a great deal of fluoride toothpaste or take fluoride supplements.  

Old Dental Fillings

Some dental materials, especially older amalgam (silver-sulfide containing) can cause staining of the teeth, though this staining is usually greyish rather than yellow.

If you need to see a dentist for a regular check or to treat a more specific dental issue, the easiest and fastest way to find a dentist near you and book an appointment online is with MyHealth1st.

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