Tooth discolouration can be as a result of either extrinsic (surface stain) or intrinsic (internal) factors. As a general rule our teeth become darker as we become older – it is a part of the normal ageing process. The milk teeth have a much whiter appearance than the adult teeth. Many people would prefer their teeth to be whiter so look at the various whitening options available.

Teeth whitening with carbamide peroxide is considered safe and effective. It should carried out in a healthy mouth. It is illegal for anyone other than a dentist to provide tooth whitening.

CAUSES OF DISCOLOURATION

There are many causes of discolouration. Our teeth can become discoloured whilst they are forming as a result of illness or the use of tetracycline antibiotics. They may also become discoloured when the nerve and blood vessels inside the root canal dies or is damaged as a result of either tooth decay or trauma. Teeth also naturally darken with age.

Surface Stain

These are usually caused by the diet – tea, coffee, red wine, melanoidins (large discoloured molecules from cooked vegetables) and some medicines all contribute. Any deposits of calculus that form around the necks of teeth where the toothbrush regularly misses can also pick up stains. A hygienist visit is very effective at removing all types of surface stain but these will return regardless of tooth whitening if their cause is still present.

Internal Stain

Teeth which have had root canal treatment, can become darker. Front teeth that have taken a heavy knock or other trauma will frequently become discoloured if the blood vessels have been ruptured at the end of the root. If a haemorrhage has taken place within the tooth itself, the usual healing process of the soft tissues cannot occur. The blood products break down in the tooth and cannot be taken away by a fresh blood supply. The tooth then appears grey.

WHAT IS TOOTH WHITENING?

Whitening is the use of chemical agents to produce oxidation of the discolouring molecules within the tooth. It is a simple process, and it is important to understand that teeth will only lighten so far; how much your teeth will lighten is very individual. Maintaining the lightened colour will require regular top-ups. At Heathwood, we use Carbamide Peroxide as our lightening agent. It works by penetrating the enamel of your teeth and oxidising the pigment bonds in the dentine, so brightening your teeth without damaging them.

WHAT DOES  LIGHTENING INVOLVE?

External Bleaching

At our practice we use 2 types of home whitening system – White Dental Beauty and Enlighten Home and In-Surgery Whitening.

Both systems involve the construction of custom-made whitening trays. These fit over your teeth and may need to be remade in the future if a big change, such as a new crown, occurs in the mouth, to allow for top up whitening (see below). Carbamide peroxide gel is placed in the whitening trays, by you, to hold the gel against the tooth surface with minimal contact with the gums or other parts of the mouth. Mild irritation of the gums resolves after a few days if they do come into contact with the gel inadvertently.

White Dental Beauty tooth whitening is used entirely at home. It allows you to determine exactly how white you’d like your teeth to be. It is also relatively flexible, allowing you to miss the odd night of whitening if you are busy. Temporary mild sensitivity is a known effect with tooth whitening, particularly if you already have sensitive teeth, but home whitening allows you to pace yourself if sensitivity affects you. We will provide you with various products and techniques to help manage the sensitivity too. 

How long the process takes varies according to the shade of the teeth at the start of the treatment and the shade you want to achieve by the end. Typically, continuous whitening will give a good result between 2-6 weeks. The trays are usually worn for 1-4 hours dependant upon the strength of gel prescribed. Teeth have a natural variation in their shade from the gum region to the tip and this will remain when teeth are whitened. 

The whitening effect is not indefinite and it is normal for teeth to regress somewhat after treatment.  A degree of maintenance is required to keep teeth looking their best. We recommend using further whitening gel (which can be bought in individual syringes from us) for 1 night roughly every other month to maintain the effect. Each syringe will provide enough gel for at least a year’s worth of maintenance and should be bought as you need it to prevent the gel expiring.

Enlighten Home & In-Surgery Whitening works in a similar fashion. It is a faster process giving a finished result in 2 weeks. It will whiten teeth to the lightest natural shade possible, which we can show you in the surgery, so they look bright and healthy. 14 consecutive nights of home whitening using trays and gel are followed by a 1 hour session in the surgery with the dentist on day 15 to complete the process. As a result of the surgery time used, the cost is higher but this is a good system for people with limited time to commit to whitening. Temporary sensitivity, gradation of colour and maintenance needed are all similar to home whitening.

Internal Bleaching

When a tooth is discoloured following root canal treatment, internal bleaching can improve its’ appearance. The root canal treatment must be sound. The bleaching agent is sealed inside the tooth for a week and repeatedly replaced until the desired effect is achieved or the colour does not change any further. Internal bleaching can relapse over time and needs to be repeated. We often combine both internal and external bleaching to maximise efficacy.

Does bleaching work on all teeth?

Teeth can generally have a yellow, brown or grey hue. Yellow hues bleach most rapidly and reliably. Brown and grey hues will improve but results and timescales are variable. It may be more appropriate to change the appearance of these teeth with crowns and veneers. Bands, blotches and spots may not respond to whitening treatment.

Tooth coloured fillings, crowns or other ceramic restorations will not change colour. If these are visible when you smile you will need to consider the additional cost to replace them to match the newly whitened teeth. It is wise to wait 4-6 weeks after whitening teeth before redoing restorations to allow the colour to stabilise and bonding to be reliable.

Heathwood Dental Practice

1 Kings Road, Crowthorne,

Berkshire. RG45 7BF

Tel. 01344776933