One of the most frequently discussed procedures with patients and friends is – “How do I whiten my teeth?”
This article covers everything you would need to know if you are thinking about whitening your teeth. We will cover all the essential things that you would want to know about teeth whitening such as
• how does teeth whitening work?
• types of teeth whitening available in the Singapore market,
• as well as debunk a few common myths that have been circulating around, for way too long now.
If you are planning to get married or have a big occasion coming up, this article will also cover preparation timeline to make sure your pearly whites are sorted out punctually.
So, let’s get started.

How does teeth whitening work?
Teeth whitening is a cosmetic dental procedure that involves lightening darkened teeth through physical and chemical means [4].
If you have external stains, a good polishing by your local dentist can help to remove these caffeine stains for example. However, this uncovers the original tooth colour, but does not actually whiten the tooth.
What whitens my teeth in whitening products?
The active ingredient in teeth whitening products is hydrogen peroxide [1], either in the form of carbamide or hydrogen peroxide. When hydrogen peroxide is exposed to the chromogens (the organic compounds within the tooth that gives teeth its colour), it causes oxidation to occur. This reaction causes an organic structural change that produces a lighter colour, producing whiter teeth!
Usually, only the front 8 – 10 teeth are whitened as these are part of the smile aesthetic zone, meaning that these are the teeth visible when you smile.
How do I know if I am suitable for teeth whitening?
That depends on the type of stains you have.
There are 2 main types of stains: internal and external. In general, if you have an internal stain, it is not possible to whiten your teeth the way you would see in most teeth whitening ads. However, if you are just an avid coffee drinker with external stains, you would stand a good chance of having whiter teeth, though perhaps cutting back on coffee may also help.

What is an External Stain?
An external stain is usually caused from the things we eat and drink, in general our lifestyle!
Habits and lifestyle factors that can cause external stains include:
● Plaque i.e. the build-up of biofilm from eating and drinking and the lack of brushing and flossing
● Any type of food and drink that is dark in colour such as coffees, teas, red wine, curries and ketchup!
● Smoking
● Tooth decay
Yellow teeth caused by external stains are an excellent candidate for teeth whitening! However, it is still important for you to have your teeth and gums checked by a dentist before starting on your whitening journey because any tooth cavities or gum issues should be sorted out first, to create a painless and pleasant whitening experience.
More on that later.
What is an Internal Stain?
An internal stain is something that happened during childhood, that caused a disturbance in the development of your adult teeth!
Teeth that are internally stained may appear bluish or brownish and are typically darkly coloured in appearance.
Internal staining can be caused by a multitude of factors and some of these include [2]:
● Taking certain antibiotics as a child (e.g. Tetracycline)
● Ingesting too much fluoride
● Genetic abnormalities
● Ageing
● Post braces spots (Orthodontic white spot lesions)
● Old metal (amalgam) fillings
Relevant mainly to people who have grown up in Singapore, fluorosis is a popular type of internal stain because our water supply contains fluoride! Though fluoride is meant to aid tooth mineralisation, too much fluoride during childhood can cause patchy teeth to develop.
So kids, please do not swallow your toothpaste!
What types of teeth whitening are available in Singapore?
According to the American Academy of Cosmetic Dentistry [3] , these are the available products
- Whitening Toothpastes
- Over-The-Counter Whitening Strips and Gels (this includes online direct to consumer products)
- Whitening Mouthwash
- Tray based tooth whitening gel
- In Office Whitening
Whitening Toothpastes tend to be more abrasive as they contain extra ingredients that sometimes with long term use, can lead to a counterproductive effect due to stripping down the outer layer of teeth causing the inner layer of dentin which is yellow, to show through.
This article will focus mainly on peroxide-based teeth whitening products available in Singapore which includes
- Tray based tooth whitening gel i.e. Take Home Whitening Kit
- In Office Whitening
What is a take-home teeth-whitening kit?
A take home whitening kit involves two things – A tray and gel.
The gel is loaded into the tray and worn for 20 minutes – 8 hours, depending on the concentration of peroxide in the whitening gel you have purchased. It is really important to follow the manufacturer’s instructions to avoid experiencing unwanted teeth sensitivity or sore gums.
Common brands on the market include
- Opalescence (30 minutes / day – 35% carbamide peroxide)
- Zenyum White (75 minutes / day – 17 %)
- Philips NiteWhite (overnight gel – 16% carbamide peroxide)
Brand & Market Price
Opalescence: $ 350 – 500
Philips NiteWhite: $ 350 – 500
Zenyum White: $ 99 - 289
The unique nature about Zenyum White compared to other whitening gel companies, is that they are able to put you in touch with a dentist from their local partner network at discounted prices for consultation.
This is a good option for those on a budget or do not have a regular dentist.
My personal opinion is that if you have your own dentist then it’s good to go back to the one who knows everything that has been going on in your mouth, to determine if you are suitable for teeth whitening or not.
What is In Office teeth whitening?
It involves a higher concentration of peroxide based whitening gel that can only be done by a professional because if the gel were to go anywhere other than your teeth, it can burn really bad.
Usually a 1-hour procedure that requires you to sit in the dental chair patiently while you would experience some teeth sensitivity due to the strong nature of the gel. However, you do come out with teeth that are generally 4 – 8 shades whiter, subject to prior teeth conditions.
There are several brands on the market, some which require a light activated gel such as Philips ZOOM, though that may weigh heavy on your mouth which can be tiring. There are other brands such as Opalescence which provide light free options and basically all you have to do is sit and wait with the gel applied.
Market price for this is $800 – 1000.
Myths about teeth whitening
Does it weaken my teeth?
Long term studies have shown that peroxide-based teeth whitening gels do not have any long-term damage to your teeth.
Why do some of my friends say teeth whitening is painful?
It could be that the gel they are using is too strong, exposure time is too long or that there was untreated decay that needs to be addressed.
Is peroxide damaging / toxic to my body?
No, it is not toxic especially when ingested over a short period of time and in trace amounts.
Tips and tricks to have super white teeth
Get an electric toothbrush to maintain good oral hygiene, like the Zenyum Sonic, Philips Sonicare or Oral B.
Avoid drinking dark drinks and foods while whitening teeth!
Choose calcium during the process to decrease any teeth sensitivity.
The best combo of teeth whitening is to do chairside teeth whitening to jumpstart the base colour to a whiter shade, then maintain every 3 months with a take home whitening kit.
Teeth Whitening Timeline
If you have a big occasion coming up, think about whitening your teeth 3 months in advance.
Just in case any pre-whitening needs have to be addressed such as fillings and dental cleaning. Teeth whitening if done chairside can be done instantly but it does take 2 weeks to see a colour stabilization.
Take home whitening kits include trays that need to be fabricated so that also takes time.
Lastly, while teeth whitening is a generally pleasant experience, it does take up to 48 hours for any tooth sensitivity to dissipate so that is worth taking into account.
I hope that this article has proven to be a good way for you to find out more before you decide to begin your teeth whitening journey!
Please note that this article is an opinion piece based on clinical practice backed with scientific evidence.