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Understanding Yellow & Stained Teeth: Causes, Treatments & More

Understanding Yellow & Stained Teeth: Causes, Treatments & More

Have you always wondered: “Why do my teeth look yellowish even though I brush my teeth twice a day?” or “Can scaling and/or polishing make my teeth whiter?”

Yellow teeth and stained teeth are two completely different conditions. If you have yellow teeth, it takes more than daily brushing and regular visits to the dentist to solve it. On the contrary, stained teeth is a condition that can be solved by scaling and polishing. To help you better understand why yellow and stained teeth can occur, we have compiled a list of causes of tooth discolouration, and also the different treatments you can seek.

What are the causes of teeth discolouration?

Why are your teeth yellowish, stained and what are the causes? Teeth discolouration has three root causes: extrinsic stain, intrinsic stain and physiological ageing.

1. Extrinsic/External Stain

Stained teeth are caused by extrinsic stains. Extrinsic stains usually deposit themselves on the surface of the enamel, which is the hard, outermost layer of the teeth. Excessive and regular consumption of strongly-pigmented beverages like coffee, tea, dark-coloured soft drink, and wine can result in stained teeth. They contain tannins, and its residue tends to stick on the surface of the teeth, tarnishing the enamel.

Extrinsic stains created by tobacco (cigarettes) often result in brownish/yellowish teeth as well. There’s also a form of extrinsic staining on teeth that’s commonly found in children, known as chromogenic bacteria staining that stems from poor oral hygiene.

2. Intrinsic/Internal Stain

Yellow teeth are caused by intrinsic stains. Intrinsic staining happens in the inner layer of the tooth when the stain-causing agents are able to pass through the enamel surface and accumulate within the enamel and dentine layer beneath. Intrinsic tooth stains are naturally more permanent and harder to tackle than extrinsic stains.

One of the more prevailing causes of yellow teeth is dental trauma. This includes the usage of certain types of antibiotics (particularly, tetracycline), developmental defects when the teeth are forming in the bone, overexposure to fluoride or demineralisation of the tooth structure due to poor oral hygiene.

3. Physiological Ageing

As a person starts to age, the enamel layer of the teeth starts wearing and thinning down due to chewing and brushing over the years, exposing the yellow dentine beneath. Therefore, yellow teeth can mistakenly make you appear older than you actually are. Luckily, discoloured teeth are not indications of a serious medical problem. However, yellow teeth can result in a loss of self-confidence and self-esteem.

Sometimes, medical treatments like chemotherapy and certain medications such as antihypertensive, antihistamines, and antipsychotic medications can contribute to discoloured teeth. If you are interested in brightening your smile, you should get yourself examined by a professional dentist, and they would recommend the most appropriate treatments to suit your needs.

What are the treatments for yellow or stained teeth?

There are 2 types of professional whitening services offered by dentists. For clarity, both home-use whitening products and in-office whitening procedures are considered “professional products and services.”

1. Professional Home Whitening Kit

A professional home whitening kit is made up of a custom-made tray that fits your teeth structure and the necessary whitening gels. When your dentist prescribes this treatment, they will have to personally customise a tray that fits your teeth comfortably so chemical injuries can be avoided, such as the whitening gels accidentally coming into contact with your gums. The whitening gel usually contains 10% to 38% carbamide peroxide and wearing times are according to the concentration used (1). Always consult your dentist before using.

2. Professional
In-Office Laser Whitening

In-office bleaching procedures, known as “power bleaching,” uses concentrated chemicals like hydrogen peroxide to lighten the natural colour of your yellow teeth. This process does not harm the tooth’s structure. Usually, a blue plasma light is used to activate the gel, speeding up the process and whitening the teeth in half the time (2). When you choose an in-office treatment such as power bleaching, there's a much better chance that your teeth will whiten due to the higher concentration of peroxide and the use of blue plasma light.

However, professional whitening performed by dentists can be costly. Therefore, most dentists will recommend the usage of over-the-counter products. It makes teeth whitening easy and affordable for everyone. However, it does require more effort for it to be effective.

3. Over-The-Counter Teeth Whitening Products

One of the common products you can find in selected pharmacies are whitening strips. Whitening strips are very thin, transparent plastic strips that are coated with a peroxide-based whitening gel. Wearing time varies depending on the strength of the peroxide. Initial results are often seen in several days, and its effect usually lasts for two to three months.

Whitening toothpastes are more sustainable compared to the other solutions. Here’s why:

  • Whitening toothpastes contain mild abrasives that can remove extrinsic stain that’s present on the surface.
  • Whitening toothpastes can also lighten the tooth's color by about one shade. Dentists usually advise using it as a maintenance protocol to keep your teeth white.
  • Whitening toothpastes also prevent extrinsic staining after undergoing a professional whitening service.

Popular home whitening remedies such as charcoal, baking soda, and lime mint have been incorporated into ready-to-use toothpastes, so you can say goodbye to messy DIY mixtures. Maintaining a bright smile has never been easier. Enzyme is a known ingredient that enhances the cleaning efficiency of many types of products (3), including toothpastes and mouthwashes (4). Therefore, toothpaste that contains enzyme(s) is another option you can consider.

All in all, discoloured teeth do not bring harm to your health. It does, however, affect your smile and self-confidence.

However, before choosing a treatment to whiten your teeth, always consult your dentist for an accurate assessment and advice. It is also crucial to know that while professional tooth whitening methods can whiten your teeth, it will eventually fade away. Therefore, it is advisable to continuously use home-use products such as whitening toothpaste. To learn more about your teeth, visit our blog now.


  1. Marshall, K., Berry, T. G., & Woolum, J. (2010). Tooth whitening: current status. Compendium of continuing education in dentistry (Jamesburg, N.J. : 1995), 31(7), 486–508.
  2. Al-Maliky M. A. (2019). Clinical Investigation of 940 nm Diode Laser Power Bleaching: An In Vivo Study. Journal of lasers in medical sciences, 10(1), 33–36.
  3. Olsen, H. S., & Falholt, P. (n.d.). The role of enzymes in modern detergency. Journal of Surfactants and Detergents.
  4. Aehle, B. E. D. W., Aehle, D. W., & Division, G. A. D. (2007, October 12). Industrial Enzymes. Wiley Online Library.

Dr. Jimmy Yap

Founder and principal dentist of a successful private dental practice in Kuala Lumpur, Dr Jimmy Yap cherishes all the beautiful smiles he has helped make possible. Graduating from the prestigious University Malaya with the Hadiah Buku Universiti Award, he has a special interest in Orthodontics, Root Canal Treatment and Aesthetic Dentistry. In his free time, he shares his rich knowledge in dentistry with those who are keen.

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Understanding Yellow & Stained Teeth: Causes, Treatments & More