How to Whiten Teeth: 10 Essential Facts You Must Know (2024)

Dental Designs Clinic Singapore
16 Feb, 2024

Ever wanted pearly whites like your favourite movie stars? Tooth whitening or bleaching can provide you with a bright and white smile that you can confidently show and make a great first impression. 

Read below to find out how to make teeth white and more about teeth whitening in Singapore!


1) How does teeth whitening treatment work?

Tooth whitening uses bleaching agents, specifically carbamide peroxide and hydrogen peroxide, to lighten the colour of the teeth. Since our teeth are semi-permeable, these chemicals penetrate the tooth enamel to remove stains1. Teeth stains can be classified as intrinsic (occurring within the tooth) or extrinsic (occurring on the tooth's surface). Click here to read more about the different types of stains on teeth.

Understanding the type of stains you have can help determine the most effective whitening treatment, when undergoing the teeth whitening process in a dental clinic, dentists often use special whitening lights which catalyses the chemical process, thus accelerating the whitening process.


2) Why do I have stained/yellow teeth?

The colour of our teeth is determined by the layer of tooth enamel covering them. Teeth may be intrinsically discoloured as tooth enamel naturally comes in different shades varying from light yellow to off-white.

Tooth discolouration can be caused by a variety of lifestyle factors including poor dental hygiene, consuming stain-causing foods and beverages like coffee and red wine, and natural ageing and heavy smoking. It is also natural for teeth to change color and become darker or yellow as we age. The teeth whitening procedure is becoming a popular option among older individuals seeking a more youthful appearance.


3) Will teeth whitening treatment make my teeth sensitive?

In-office teeth whitening is a minimally invasive procedure and when performed by a qualified dentist is safe without any long term side effects. During teeth whitening, channels in the tooth enamel open to allow stains to be drawn out, and thus it is expected to experience some sensitivity during the treatment.

Tooth sensitivity is a common side effect of teeth whitening, especially with stronger whitening agents. Your dentist can recommend desensitising treatments to alleviate discomfort with potassium nitrate and sodium fluoride gel to alleviate this temporary sensation of sensitivity. Click here to read if it's alright to whiten teeth that are sensitive.


4) How much improvement to the whiteness can I expect to see?

The extent of whitening and brightening of the teeth is reliant on numerous factors, including the individual tooth condition, the thickness of the tooth enamel, the cause of discolouration and how effectively the dentist’s post-procedural instructions were followed.

Your dentist will be able to guide you how to whiten teeth and to achieve a shade of white which you will be happy with after treatment and will consult with you before the treatment starts to diagnose and plan your treatment.


5) Can I treat a single dark tooth?

A single dark tooth is usually due to two factors. The first factor is due to root canal treatment on the affected tooth. In such cases, your dentist may suggest internal bleaching, veneers or crowns. The second reason for a single dark tooth is pulp degeneration, often triggered by trauma to the tooth.

Teeth whitening treatment of a single dark tooth is therefore, more complex and may require veneer or crowns to cover up the colour. It is always best to consult with your dentist who will be able to recommend an effective treatment. 


6) How to whiten teeth that have blue or grey discolourations?

Such blue or grey discolourations typically respond less well to tooth whitening procedures and as a result, require a longer treatment time. The underlying cause of such discolouration may be due to antibiotics such as Tetracycline consumed when younger, which leads to a band of discolouration that affects many teeth.

Natural translucency in the teeth can also appear as grey patches and this is not possible to improve through teeth whitening. If your teeth has white or brown patches that gives it a mottled appearance, these teeth will respond to teeth whitening but the white patches may still look uneven. ICON treatment can help to even out patchy teeth.

We provide ICON treatment at Dental Designs Clinic. You can read more on it here


7) How to get white teeth — In-office teeth whitening or take-home whitening kits?

In-office whitening offers you immediate results, revealing a smile of at least 2-4 shades whiter than your current teeth. The process utilises higher concentration whitening gel that is activated by laser or light2 to accelerate the whitening process. Your lips and gums will be protected from the bleaching agent with rubber seals or gel that the dentist prepares beforehand.

In office whitening is good for yellowish or darker teeth as the stronger whitening gel concentration can be more effective. However if the starting shade is very dark, multiple sessions may be required to achieve enhanced whitening effect.

Home whitening kits, in contrast, deliver a more gradual whitening outcome. The dentist will take a mould of your teeth to make custom-fit trays. At home, you will be able to fill these trays with bleaching gels and wear them between an hour to overnight, depending on your dentist’s instructions.

These gel-filled trays are needed to be worn for at least two to four weeks. This gradual process allows you to lighten tooth shades according to your preference, as well as to spot treat certain teeth which may be more yellowish. 

patient looking at mirror smiling

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8) Do I need to avoid certain foods after I whiten my teeth?

We would recommend avoiding certain foods and beverages immediately after teeth whitening. Those that can potentially stain or discolor your teeth or are likely to irritate your sensitive teeth should generally be avoided. These include dark coloured food and drinks, like coffee and tea, as well as acidic food and drinks such as citrus fruits and carbonated drinks as they may excerbate teeth sensitivity. A general rule is, anything which can stain a white napkin, should be avoided.


9) Is teeth whitening in Singapore permanent?

Teeth whitening is not permanent and factors such as lifestyle choices, dietary habits and natural tooth discolouration can gradually diminish the whiteness achieved through whitening treatments. On average, both in-office and take-home teeth whitening treatments can maintain their effects for up to 3 years. However, it is recommended to go for periodic touch-ups to keep your smile bright and white.


10) It is best to discuss how to make teeth white with your dentist!dentist-performing-in-office-whitening

Each patient will experience different results due to the differences between our teeth. Patients often ask us, "Does whitening teeth weaken enamel? How to whiten teeth naturally?"

Well, your dentist is still the best person to advise about teeth whitening in Singapore. They will perform a comprehensive intraoral examination with a tooth shade evaluation, followed by an analysis to provide you with what to expect during the treatment as well as of the treatment outcome. 

Ready to explore the world of teeth whiteningBook an appointment with us!



  1. Heymann HO. Tooth whitening: facts and fallacies. Br Dent J. 2005 Apr 23;198(8):514. doi: 10.1038/sj.bdj.4812298. PMID: 15849600.
  2. Luk K, Tam L, Hubert M. Effect of light energy on peroxide tooth bleaching. J Am Dent Assoc. 2004 Feb;135(2):194-201; quiz 228-9. doi: 10.14219/jada.archive.2004.0151. PMID: 15005435.