Why Are My Teeth Discoloured? Understanding What Affects Tooth Colour
Your smile is often the first thing people notice about you, and tooth colour plays a big role in making it memorable. But if you’ve ever wondered why your teeth don’t look as white as they used to, you’re not alone. Tooth discolouration isn’t always about brushing habits—there are many internal and external factors at play.
In this blog, we’ll explore what affects tooth colour, the difference between extrinsic and intrinsic causes, and what you can do to protect and restore a brighter, healthier smile.
What Determines Tooth Colour: An Overview
The natural shade of your teeth comes from a combination of enamel (the hard, outer layer) and dentin (the softer, yellowish tissue underneath). Factors like enamel thickness, translucency, and dentin colour all contribute to how white or yellow your teeth appear.
Tooth discolouration generally falls into two categories:
Extrinsic (surface) stains – caused by lifestyle habits and external elements.
Intrinsic (internal) stains – caused by genetic, medical, or developmental factors.
Extrinsic Factors: Everyday Causes of Tooth Discolouration
1. Certain Foods and Beverages
Dark-coloured foods and drinks like coffee, tea, red wine, berries, and soy sauce contain chromogens—pigments that stick to enamel and leave stains. Acidic foods also wear down enamel, making stains easier to penetrate.
2. Tobacco Usage
Smoking or chewing tobacco exposes teeth to tar and nicotine, causing yellow, brown, or even black stains that can be tough to remove without professional care.
3. Tartar Build-Up and Poor Oral Hygiene
Plaque that isn’t cleaned properly hardens into tartar, which not only discolours teeth but also traps stains. Brushing and flossing daily, combined with regular dental cleanings, helps prevent this.
4. Enamel Erosion and Aging
As we age, enamel naturally wears away, revealing more of the yellowish dentin beneath. Everyday wear, acidic foods, and grinding can all speed up enamel loss, making teeth appear darker.
Intrinsic Factors: Internal Causes of Tooth Colour Changes
5. Medications and Medical Treatments
Certain drugs, like tetracycline and doxycycline (especially in children), can stain teeth during development. Other medications, such as some antihistamines, antipsychotics, and antibiotics, may also cause discolouration. In addition, chemotherapy and radiation therapy can darken teeth.
6. Genetics
Your DNA plays a big role in tooth colour. Natural variations in enamel thickness, translucency, and dentin shade mean some people are predisposed to naturally whiter or yellower teeth.
7. Fluorosis (Excessive Fluoride Exposure)
While fluoride protects teeth from cavities, too much during tooth development can lead to dental fluorosis, which causes white streaks, brown patches, or mottled enamel.
8. Trauma or Injury
Tooth injuries can cause internal bleeding or nerve damage, leading to a tooth that turns grey or dark over time. This often affects only one tooth.
9. Root Canal Treatments and Aging Restorations
Teeth that undergo root canal therapy may darken due to internal changes or the materials used. Likewise, older dental fillings and crowns can lose their colour or stain, affecting your overall smile.
Combined & Age-Related Effects
Often, discolouration is the result of both external and internal factors working together. For example, as enamel thins with age, stains from coffee or smoking become more noticeable. This is why tooth colour naturally changes over time, even with good oral hygiene.
Prevention: How to Keep Your Smile Bright
Practice consistent oral hygiene – brush twice daily, floss, and use mouthwash.
Limit stain-causing foods and drinks – or rinse your mouth with water after consuming them.
Quit tobacco – to prevent stains and protect your overall health.
Protect your teeth from trauma – by wearing mouthguards during sports.
Balance fluoride intake – especially in children.
Discuss medications with your dentist if discolouration becomes noticeable.
When to See a Dentist: Treatment Options
If discolouration persists despite good habits, your dentist can recommend treatments such as:
Professional teeth whitening – more effective than over-the-counter products.
Cosmetic restorations – veneers, crowns, or bonding for intrinsic stains.
Scaling and polishing – to remove tartar and surface stains.
Your dentist will determine the best treatment depending on whether the stains are extrinsic, intrinsic, or a combination of both.
Conclusion
Tooth colour is influenced by many factors—some within your control, and others determined by genetics or medical conditions. While you may not be able to prevent all forms of discolouration, maintaining strong oral hygiene, making mindful lifestyle choices, and seeking professional dental advice can help keep your smile healthy and bright.
FAQs
1. Why are some people’s teeth naturally more yellow?
Genetics determine enamel thickness and dentin colour, making some teeth appear naturally more yellow.
2. Can whitening toothpaste fix deep stains?
Whitening toothpaste may help surface stains but won’t remove intrinsic or severe discolouration.
3. How safe is professional whitening?
When done by a dentist, whitening is generally safe but may cause temporary sensitivity.
4. Can children develop tooth discolouration?
Yes—fluorosis, trauma, and certain medications can affect children’s developing teeth.
5. How often should I get my teeth professionally cleaned?
Most dentists recommend twice a year, but more frequent cleanings may be needed for smokers or those prone to tartar buildup.