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