Dental Articles

Why are my teeth yellow when I brush them every day? Habits Singaporeans can correct.

Most Singaporeans don’t realise that their daily habits are one of the biggest reasons why they have yellow teeth despite keeping up with their dental hygiene.

Think of it this way: if you drink bubble tea once a year, the effects of the high-sugar drink will be negligible.

However, if you do it multiple times a week, it will have a significant effect on your weight, health and wallet!

Maintenance of teeth is the same. If you are the type of Singaporean who starts their day with a cup of kopi-o or smokes multiple times a day, you might be accelerating the staining of your teeth.

Luckily, with a change in habits and some professional dental help, you can get great pearly whites that you will feel confident about when you smile.

Reason 1: your diet involves a lot of staining foods

If you have eaten a curry dish like laksa or roti prata, you might have stained your shirt with the gravy.

Notice how difficult getting curry stains off your shirt. It’s even worse when you’ve just stained a white shirt.

Among the many foods and drinks Singaporeans consume, curry, coffee, tea, wine represent some of the most staining foods out there.

The same logic applies to teeth. When you consume staining foods and drink, your teeth will naturally get tinted. These are called extrinsic stains.

If you have removed blood from a shirt, you’ll know that the quicker you do it, the more effectively you can remove the stain.

Extrinsic stains are the same. As they are mostly surface-deep, they can be treated by regular brushing and rinsing after a meal.

Regular cleaning is effective to remove extrinsic stains.

Reason 2: you smoke

Smoking is damaging to your teeth because of how nicotine causes deep yellow stains.

By itself, nicotine doesn’t have any colour. However, when mixed with oxygen, such as when you inhale, it becomes yellow and stains teeth.

Unlike stains caused by food and drinks, nicotine discolouration can appear spotty or in clusters. Food-related stains are more uniform.

People who smoke many cigarettes a day will generally see this pattern of discolouration much quicker as their teeth encounter nicotine much more frequently.

Reason 3: your brushing needs an upgrade

Are you using the right technique to ensure that you are brushing every part of each tooth?

Poor brushing techniques that miss areas will allow surface stains to get embedded into a deeper layer the called the enamel.

On the same note, brushing too hard will wear your enamel away which will reveal the dentin, which is naturally yellow in colour.

Most Singaporeans struggle to remove stains and plaque in harder-to-reach areas such as the near the gumline and on the rear teeth.

Having some guidance on how to brush effectively will help you more effectively control stains over the long term.

Reason 4:Your genes and you

Some people are luckier in that they have thicker enamels and others have thinner enamels.

Enamel is the whitest part of our teeth with deeper layers being darker and yellower.

Unfortunately, time causes wear on enamel, even if you are on-the-ball with brushing and dental check-ups.

This does mean that everyone will have teeth that look yellower as time passes, but some are luckier to have their white teeth last longer.

How can I get whiter teeth?

You have decent control over the yellowing of your teeth, and with a combination of adopting sustainable habits and seeking professional dental help, you can have great pearly whites that will give you the confidence when you smile.

Habit 1: Use a whitening toothpaste

If you haven’t given much thought to your toothpaste, now’s the time to invest in a whitening toothpaste.

A whitening toothpaste has a special formulation that goes beyond what a regular toothpaste can do such as:

  • Polishing abrasives
  • Chemicals like peroxide to remove stains

They are great as a quick way to upgrade your dental hygiene regimen. They remove external stains effectively. Combined with regular and thorough brushing, you can stop external stains from developing further into the tooth.

The abrasive particles in whitening toothpaste help to whiten the teeth but it also roughen the teeth surface resulting in more stain to be trapped on the surface of the teeth.

What about teeth-whitening kits?

Teeth whitening kits and services offered by non-dental professionals aren’t likely to work due to one major reason:


The MOH only permits dentists to have access to the full-powered whitening agents that can really get to the core of teeth that have become intrinsically yellow.

Whitening agents used in unregulated kits have a maximum concentration of 0.1 per cent.

The low concentration avoids any severe problems that come from user error, but this is far too low for any meaningful effect.

To put it into context, our clinic has access to whitening kits with up to 45% concentration of bleaching agents.

Habit 2: brush effectively and regularly

Make sure you are doing these:

  • Not brushing too hard, which wears down the enamel
  • Using a soft toothbrush to protect the enamel
  • Floss daily
  • Brush with the right technique to ensure all areas of your teeth are covered
  • Visit a dentist every 4-6 months. A dentist can advise you of your brushing quality

Bad habits you have to stop now!

Of the many DIY methods to whiten your teeth, here are some that might seem effective but are incredibly damaging over the long term.

Using acidic citrus fruit to “sand” your teeth

You might have heard the suggestion to rub orange peels or lemon on your teeth to whiten your teeth.

This is very, very bad for your enamel. Remember, your enamel is non-renewable!

Acid interacts with enamel and wears it down.

It’s similar to taking sandpaper to a very thin piece of wood. Within years, you’ll have nothing to sand.

Sure, you will see improvement of your teeth’s colour. Until the day when there’s no more enamel to erode.

Your enamel is precious and it’s the only layer that can sustain a white colour.

If you believe drinking soft drinks is bad for your teeth, then it’s equally bad to subject your teeth to a fruit’s acid.

Baking soda guarantees to shorten your enamel’s lifespan

If you have a severe stain on your stove, toaster oven or countertop, you might turn to baking soda to remove that stain.

So why shouldn’t you use it on your teeth?

Just like the problem of using acidic fruits to whiten your teeth, you are basically wasting away the precious layer of enamel.

Baking soda is extremely abrasive. When used on appliances, there’s no problem because these appliances are replaceable and probably made of a harder material than baking soda.

Enamel isn’t replaceable and is rather soft. Remember that harsh brushing can degrade your enamel.