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What it is teeth whitening?

The colour of teeth varies between individuals and at different ages. Teeth can gradually change colour or become darker through the years as a result of ageing, external discolouring beverages and food, dark and discoloured filings, and mechanical and chemical trauma. Tooth colour is also influenced by an individual’s genetic makeup. When our teeth darken due to deposits or stains, a thorough cleaning should be undertaken before teeth whitening. Teeth-whitening is a dental procedure to lighten the colour of natural teeth.

Who would benefit from teeth whitening?

  • Individuals with natural teeth with minimal restorations, root exposure, cervical caries and enamel damage.

  • Individuals with types of superficial discolourations caused by beverages, food, or smoking.

  • Individuals who strictly adhere to the home whitening protocol as well as the postoperative aftercare.

What are the procedure for home teeth whitening?

The dentist takes impressions of your teeth to make custom-made, flexible whitening trays that fit around your teeth. The whitening gel is placed in the tray following the dentist’s instructions. The whitening trays are filled with whitening gel and applied for several hours at a time when convenient. The teeth will become gradually lighter over a period of 2-3 weeks, depending on the initial severity of the discolouration, the hydrogen peroxide concentration and the duration of application.

Dental whitening techniques normally use Sodium-perborate or Carbamide-peroxide with a content of up to 3% to 6% hydrogen peroxide (H2O2). Depending on the nature and depth of the discolouration, some teeth or dentitions may tend to gradually regress in darkening. Therefore, to improve and maintain the obtained lightened teeth, the existing whitening trays can be re-used for home-whitening procedures at intervals when needed.

What are the clinical procedures for chair-side or office teeth whitening?

To achieve the fastest whitening results, some manufacturers advocate in-office consumption of higher strengths of hydrogen peroxide (H2O2) gel directly to the teeth surfaces for a period of 10- 20 minutes.

To protect the surrounding soft tissues (i.e., lips, gums, cheeks and tongue) against the caustic effect of the strong hydrogen peroxide and light, a plastic retractor will be placed in the mouth and the gum will be protected using special paste.

Teeth Whitening Dental Treatment London

Due to the higher concentration of hydrogen peroxide, more postoperative teeth hypersensitivity is reported with office whitening. The effect of home whitening alone has been shown to last longer than chairside whitening; however, to achieve the most efficient outcome, a combined method of home-office whitening has been advocated by a few manufacturers. At the London Specialist Dentists clinic, we implement the Combined method of whitening under the safest and most efficient protocol, which requires the lowest concentration of hydrogen peroxide with minimal post-operative teeth hypersensitivity.

Are there any risks or concerns during and after teeth whitening?

Depending on the nature of deeply discoloured or multi-coloured teeth, teeth whitening procedures are not equally effective as some teeth in the same dentition may get lighter to a different extent. Teeth with superficial staining or discolourations lighten more efficiently and more quickly than others. Darker teeth, as a result of root exposure or gum recession, can be resistant to whitening and become hypersensitive to excessive use of hyperoxide. Certain types of tooth discolouration do not respond easily and may require special treatment by a dentist.

Dark, deteriorated fillings, veneers or crowns or marginal cement exposures will not respond to teeth whitening, whilst replacing such restorations to match the newly lightened natural teeth can be costly. Please discuss this with your dentist before considering teeth whitening procedures. The extensive clinical data support both the safety and effectiveness of tray-based tooth whitening with 6% Hydrogen peroxide gel or 18% Carbamide Peroxide gel. Temporary tooth sensitivity during and after teeth whitening procedures could be ameliorated by the use of fluoride gel or other anti-sensitive agents. When the custom made are not fitting well are not of good quality the overfilled gel loaded into the trays may be leaking out of the trays during the uses and temporarily irritate the peripheral soft tissues particularly the gums.

FAQ – What do patients usually ask about teeth whitening?

What are the alternatives dental treatments to teeth whitening?

Teeth whitening procedures offer the advantage of not destroying the healthy tooth structure. However, teeth whitening may not always be the most efficient treatment of choice to sufficiently treat aesthetically disturbing damaged teeth, large, discoloured fillings, and deep tooth discolourations (e.g. drug-induced tetracycline discolourations).

As an alternative treatment, white composite filling materials could also be used to camouflage or disguise the underlying colour of the teeth.

The provision of laminate porcelain veneers or crowns can improve the shape, form and colour of the underlying tooth or filling materials. Sometimes, to protect large fillings or root-filled teeth, providing a crown is an indicated option.
However, care should be taken not to remove a significant amount of sound natural tooth substance and to avoid tooth-destructive procedures instead of efficient teeth whitening.


The management of discoloured teeth following intra-pupal bleeding, pulp necrosis or root canal treatment could be successfully pursued by implementing combined intra-coronal and extra-coronal teeth whitening techniques as a valid treatment modality in terms of safety, efficacy, time efficiency and aesthetic outcome.

The discoloured non-vital teeth have shown chromatic stability when subjected to the combined teeth whitening technique.

Internal tooth whitening usually requires 2 or 3 settings lasting a couple of days and using a stronger concentration of peroxide. Once sufficient whitening results have been obtained, the dentist will replace the temporary filling with a new composite filling.

Teeth Whitening Case Studies

See our teeth whitening before and after photos from our happy patients.

Teeth Whitening Dental Treatment London

Before and After Treatment

Internal teeth discolouration caused by amalgam fillings and chronic decays.

Before and After Treatment

Discoloured, eroded and fractured unaesthetic anterior teeth; Aesthetically disturbing smile line.