Why your teeth look yellow and how to keep them white

I brush twice a day, so why aren't my teeth white?

It's one of the questions we hear most often at our clinic in JLT. The answer is rarely you're not brushing enough. It's usually a mix of what your teeth are made of, what you drink, and small daily habits.

Yellow isn't always stain

There are two different problems that look alike in the mirror.

Surface stains sit on the enamel.

Coffee, tea, tobacco and dark sauces cause them, and they respond well to professional cleaning and whitening.

Deeper colour comes from the layer under the enamel, called dentin, which is naturally yellowish. Enamel is slightly translucent, so as it thins with age, grinding or acid wear, more of that yellow shows through. Brushing harder doesn't fix this and can make it worse.

That's why two people with the same coffee habit can have very different looking teeth.

How common is it?

We don't have a single UAE wide figure to quote, so here is what international studies show. In a study of 405 adults and teenagers in Chengdu, China, about 49% had some tooth discolouration and about 53% were unhappy with their tooth colour. In a clinic based study in Malaysia, 56% of patients were dissatisfied with the colour of their teeth, and whitening was the treatment they wanted most, at 48%.

Wanting whiter teeth is normal, and it's worth understanding the cause before choosing a treatment.

Where is the yellow? A quick self check

Look at your teeth in daylight, not bathroom lighting, which can make everything look warmer.

• Yellow or brown along the gumline: often plaque or tartar build up, which a professional clean can remove.

• Even yellow across the whole tooth: usually natural dentin colour or thinner enamel, where whitening tends to help.

• Brown lines between teeth: stain trapped where a brush doesn't reach, often from tea, coffee or tobacco.

• One tooth darker than the rest: this is different. A single grey or dark tooth can point to an injury or a problem with the nerve, and it needs a dentist rather than whitening.

Coffee, tea and karak: how you drink matters more than what

Dubai runs on coffee, karak chai and gahwa. We rarely tell patients to give them up. The bigger factor is how long your teeth are bathed in them.

Finishing a cup in 15 minutes exposes your teeth once. Sipping the same cup over three hours, or an iced coffee through a whole workday, keeps the stain contact going. As a rule of thumb, we suggest:

• Drink it in one sitting rather than sipping all day

• Rinse with plain water afterwards

• Use a straw for iced drinks, so less liquid washes over your front teeth

• Wait about 30 minutes before brushing after coffee or other acidic drinks, because brushing softened enamel can wear it

Also watch strongly coloured foods common here, such as saffron and turmeric dishes, dark sauces, and berry juices.

Smoking and shisha

The evidence on smoking is clear. In a national UK survey of over 3,000 adults, 30% of smokers were dissatisfied with their tooth colour compared to 15% of non smokers. The researchers also found that smokers reported discolouration almost twice as often as nonsmokers.

Shisha is often seen as milder, but that's not how teeth see it. Dental writers describe shisha as notorious for staining through tar and nicotine, with stains that are hard to brush away, and the American Dental Association notes that scientists estimate hookah smokers inhale about as much smoke as from 100 cigarettes.

The sugar and fruit flavourings can also encourage bacterial growth and enamel erosion. In a laboratory study comparing smoking methods, cigarettes caused the greatest colour change, but shisha and e cigarettes also caused some. Tobacco also affects results afterwards: the ADA says that whitening may not work as well or last as long in smokers.

Habits people don't suspect

• A dry mouth. Saliva helps rinse stain causing particles away. Long days in air conditioning, not drinking enough water, and fasting hours during Ramadan can all leave your mouth drier than usual. Drink plenty of water between iftar and suhoor, and be careful about dark tea and coffee straight after a long fast.

• Some antibacterial mouthwashes. Certain prescription types can cause brown staining with long term use. Only use them as directed by your dentist.

• Medication and childhood history. Some antibiotics taken while teeth were forming can cause grey or brown bands inside the tooth, which surface cleaning can't remove.

• Skipping the dentist's clean. Tartar is porous and holds stains. Brushing can't remove it once it hardens.

How to keep your teeth white

1. Brush twice a day with a fluoride toothpaste, using a soft brush and gentle pressure.

2. Clean between your teeth daily. Stain and plaque collect where the brush can't reach.

3. Rinse with water after coffee, tea and dark foods.

4. Get a professional clean about every six months, or as your dentist advises.

5. Cut down on smoking and shisha. Nothing else helps as much.

6. Drink water through the day to keep saliva flowing.

When whitening makes sense

Teeth whitening works best on natural teeth with surface or general discolouration, but it has limits:

• Fillings, crowns and veneers don't whiten. If you have front tooth restorations, plan the shade with your dentist first, or you could end up with mismatched colours.

• Get a clean first. Whitening over tartar and plaque gives uneven results.

• Expect some sensitivity. It's common and usually temporary, but tell your dentist if you already have sensitive teeth.

• Follow the aftercare. Dentists commonly advise avoiding strongly coloured food and drink, and tobacco, for a day or two afterwards while teeth are more porous. Your dentist will give you exact instructions.

When to see a dentist

Book an appointment if one tooth has changed colour, if the yellowing came on suddenly, if you have pain or swelling, or if stains keep returning quickly after a clean. A whiter smile is a cosmetic goal, but a change in colour is sometimes a sign that something needs treatment.

Written by the clinical team at Dentism, a multi specialty dental clinic in Jlt, Dubai, offering cosmetic dentistry, orthodontics, and general dental care. Learn more at dentism.ae.