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Tooth Whitening

Tooth Whitening - What it is

Tooth whitening or bleaching is a process to reduce tooth discolouration to a lighter shade. It removes the staining agent through chemical means, and is a safe procedure when carried out under professional supervision.​

Tooth Whitening - Symptoms

Tooth Whitening - How to prevent?

Tooth Whitening - Causes and Risk Factors

Teeth can discolour for various reasons. Some teeth are more yellow than others, while others yellow with ageing. Some of the factors that can affect natural tooth colours are:

  • Use of tobacco
  • Drinking coffee, tea, colas or red wine
  • Consuming pigmented foods and drinks
  • Accumulation of plaque or tartar deposits
  • Severe fluorosis
  • Treatment with the antibiotic tetracycline during childhood
  • Trauma to the teeth that may cause a brown, grey or black colour

Tooth Whitening - Diagnosis

Treatment results usually depend on the severity of the discolouration. Both vital (i.e. live) and non-vital teeth (e.g. root canal treated) can be bleached and may take several visits to complete.

Bleaching or tooth whitening is not effective on dental restorations such as amalgam or tooth-coloured fillings, metal or porcelain crowns, etc. People with worn tooth enamel, receding gums, sensitive teeth, untreated cavities, and heavily restored teeth should consult a dentist before undergoing any teeth whitening procedures.

Your dentist will be able to recommend the most ideal method of teeth whitening treatment after an in-office examination, when the cause and nature of your tooth discolouration can be established. Your dentist will also provide you with more information on the various types of whitening procedures available, their duration and frequency of treatment.

Tooth Whitening - Treatments

Whitening methods include:

i. In-office Chair Side Bleaching

  • For the busy individual who wants ‘instant’ results.
  • Teeth can be whitened in one sitting within one to two hours.
  • Light-activated bleaching gels to speed up the process, severely discoloured teeth may need repeat
  • With proper care, results can last one year.

ii. Dentist-supervised Home Bleaching

  • A customised tray to hold the bleach.
  • You will be provided syringes of the bleaching gel and taught how to use it.
  • Bleaching is done at your convenience at home, for one hour a day.
  • This method of tooth whitening is less costly than in-office bleaching. The bleaching process is gradual, over a few weeks, but is kinder to your teeth.
  • Your dentist will review your progress regularly until the desired shade is achieved.

iii. Non-vital bleaching

A tooth can discolour after root canal treatment has been performed on the tooth and it usually has a much darker appearance as compared with adjacent teeth.

Non-vital bleaching involves placing the bleaching agent into the pulp chamber of the root canal treated tooth. This can help to lighten the colour of the tooth in some cases. Root canal treated teeth with larger restorations or severe discolouration that cannot be corrected by non-vital bleaching are better crowned.


  • A bleaching compound is placed inside the pulp chamber and sealed within the tooth.
  • The patient is reviewed in two weeks and if the tooth has been whitened sufficiently, the bleaching compound is removed and the tooth restored.

Tooth Whitening - Preparing for surgery

Tooth Whitening - Post-surgery care

Tooth Whitening - Other Information

The information provided is not intended as medical advice. Terms of use. Information provided by SingHealth

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