Tooth Whitening

What is tooth whitening?

Dental bleaching or tooth whitening is a method of lightening the colour of natural teeth. The colour of teeth varies between individuals and at different ages – teeth can gradually darken naturally over time. Tooth colour is influenced by a person’s genetic makeup and by any surface stains or deposits in or on the teeth. If teeth are dark due to external stains or deposits they will need to be cleaned before tooth whitening is undertaken.

Candidates for professional tooth whitening.

Eligibility for treatment is determined through information you provide and is gathered during your consultation and screening. While many individuals will qualify for treatment, not all people are deemed candidates for the procedure. If this is the case the dentist will discuss their findings with you and advise on other possible treatment options.

Different techniques available.

A gel, normally carbamide or hydrogen peroxide, is used to whiten teeth. This system has been highly tested and shown to be very safe. Chlorine Dioxide whitening products are never used in this practice as they strip the surface off the teeth, making the teeth much more prone to further staining.

  1. Tray Systems. Impressions are taken of your teeth to make a flexible whitening tray (similar to a very thin gum shield) that fits over and around your teeth. The gel is placed in the tray and worn as advised by the dentist. Depending on the type of gel used the tray will be worn either overnight (Conventional Kits) or for 30 minutes once or twice a day (Day White Kits). The teeth will become gradually lighter over time. A course of treatment takes a variable number of days or weeks and results vary depending on the initial darkness of the teeth, the concentration of the gel used and the frequency of application. As all whitening treatments fade over time we recommend following treatment you purchase further whitening gel to allow you to top up the new colour of your teeth and keep them looking as bright as they were when you finished your whitening treatment.
  2. Enlighten System. Impressions are taken of your teeth to make a more specialised whitening tray. This tray is constructed differently and helps keep more of the gel in the tray and thus give a more predictable result. This tray MUST be worn every night for 14 nights and the gel used conditions the teeth for the second stage. On the 15th day the dentist or hygienist then uses the same tray to place a different and higher concentrate gel on the teeth for 20 minutes and then repeats this for another 20 minutes. This system guarantees to get your teeth the lightest shade you teeth will go, though it may take longer with very dark teeth than the time scale just discussed. As all whitening treatments fade over time we recommend following treatment you purchase further whitening gel to allow you to top up the new colour of your teeth and keep them looking as bright as they were when you finished your whitening treatment.
  3. Zoom power whitening. You attend for an appointment where your gums are isolated using special materials. A gel is placed directly onto your teeth and a special high intensity light focused on the teeth for 15 minutes. This is then repeated for three further times (all in the same appointment) with the appointment taking about 90 minutes to complete. No home treatment is necessary using this technique but you must be aware that all whitening treatments fade over time and so we recommend after treatment you use the aftercare kit provided, say once every month or two, in which you wear a tray with gel in it for 30 minutes. How often you need this aftercare treatment depends on your diet and how quickly your teeth discolour.

Is it safe and what are the risks?

Tooth whitening is the safest thing to do to teeth apart from doing nothing. There is a risk that the whitening process will not work quickly and the dentist will discuss the possible reasons why this might not work particularly well or why it might take longer than average. Not all teeth whiten to the same extent, particularly deeply discoloured teeth. Some teeth lighten more effectively or more quickly than others. Teeth which are already quite white only lighten a little further. Some teeth do not whiten evenly. This can be a problem where the gum has receded and the darker root surface is exposed. Such teeth or worn teeth can become sensitive with whitening. Certain types of tooth discolouration do not respond easily and require special treatment by a dentist. Fillings, veneers, crowns and bridges that match the existing teeth will not change colour with whitening. The cost of replacing these so that they match the new lighter colour of the natural teeth can be considerable and must be discussed with the dentist before whitening is undertaken. Extensive clinical data continues to support the safety and effectiveness of tooth whitening but during the process teeth may become sensitive for a period of time. This is usually only temporary and a fluoride gel or special sensitive type tooth paste can be placed in the tray and worn for up to 30 minutes before and after each whitening period to minimise the sensitivity. Temporary irritation of the soft tissues in the mouth, particularly the gums, is rare but can occur if too much gel is loaded into the trays. The dentist will advise how to help avoid this problem.

How long does the lighter appearance last?

Teeth that have been whitened have a tendency to eventually return to their original colour. The time this takes depends on a patient’s diet and whether they smoke. The colour obtained would be expected to be maintained as long as top up gels are regularly used.

What is the current legal situation?

Under European legislation, brought out to control hair bleaching by hairdressers, certain products containing hydrogen peroxide cannot be supplied for cosmetic purposes because of “cosmetic regulations”. In late 2012 the law was clarified to make it illegal for non-dentally qualified people to carry out tooth whitening. Tooth whitening materials are perfectly safe when used under the supervision of a dentally qualified professional person.

What are the alternatives?

The only other ways to change the colour of teeth involves drilling the teeth or bonding white filling material onto them. In some instances tooth whitening will not be able to deliver the desired result and then invasive techniques must be considered. The great advantage of tooth whitening is that is does not involve the destruction of existing healthy tooth structure. This type of tooth destruction has been shown to produce tooth death, requiring root canal therapy, in up to 10% of teeth prepared for veneers, crowns or bridges.