What is tooth whitening?

It is an oxidising process that lightens the colour of enamel and dentine. The system we recommend uses a gel which is retained in a custom made tray which is worn over your teeth for 3 hours during the daytime or while you sleep. 

The tray design incorporates a reservoir that holds the product against the tooth whilst keeping it away from the gum. As the active ingredient in the gel is broken down oxygen enters the dentine and enamel and liberates the pigment molecule causing the tooth to whiten. The structure of the tooth is not changed; the tooth is just lighter and brighter.

What causes tooth discolouration?

There are many causes including ageing, drinking coffee, tea, coke and red wine, smoking, trauma, tetracycline (antibiotic) staining, non-vital teeth and old silver fillings. Some people have genetically inherited teeth which are darker in colour. 

Changes in temperature of foods and drinks cause the teeth to expand and contract which allows the coloured proteins from tea, coffee etc. to penetrate the teeth. Foods that are acidic also open up microscopic cracks in the enamel and allow stains to move in.

Who can benefit from tooth whitening?

Almost everyone, however there are some cases where the treatment may not be appropriate. Tooth whitening will not change the colour of existing fillings or crowns so if you have a lot of fillings or crowns at the front of your mouth another cosmetic procedure may give you a better result. 

If you would like new crowns or fillings it is sensible to whiten the natural teeth first then match the fillings or crowns to the brighter, lighter teeth. The tooth whitening system is ideal for patients who have healthy unrestored teeth and would like to have a brighter smile. Teeth tend to change shade, usually yellow with age. These changes can be reversed. 

Some people inherit darker teeth in much the same way as differences in hair and skin colour. This can also be changed. Teeth that are stained grey (such as tetracycline staining) can be more stubborn, but still possible to treat.

Is tooth whitening safe?

Yes. Research has shown that whitening is safe for the teeth and gums under the supervision of a dentist. The custom made trays isolate the gel to the teeth that need to be whitened and keeps contact with the gum to a minimum.

How long does it take?

Some results are usually seen after the first treatment. Maximum results generally occur when the process is continued for 10-14 days when worn for a 3 hour session each day (or 10-14 nights). This whitening system can achieve a shade change of between 6-9 shades depending on the patient and the duration of the treatment.

Why don’t you use a laser/light in the surgery to whiten teeth?

Some dentists will use a blue light to whiten teeth (sometimes called Zoom whitening) which usually takes a couple of hours in the chair. 

It does give immediate results, however research has shown most of the whitening effect is due to extreme drying of the tooth and the whitening is only temporary, and it costs considerably more which makes it an expensive option.

Are there any side effects?

The gel that we use at Andrews Dental Care contains potassium nitrate a desensitizer and sodium fluoride which reduces the likelihood of sensitivity. Consequently very few patients experience sensitivity to cold during treatment. 

These symptoms can be controlled and always disappear within 1-3 days after interruption or completion of treatment.

For patients with a history of sensitive teeth we recommend the use of desensitizing toothpaste (Sensodyne Gentle Whitening) or GC Tooth Mousse which is a milk based conditioner and may be worn in the tray a few times prior to commencing the tooth whitening process with the gel.

How long will the results last?

Your teeth will always be lighter than they were however you may need periodic ‘touch-ups’ for one or two nights every 6-12 months to keep them fabulous especially if you continue to smoke or drink coffee, red wine etc. 

You can still use your original trays and should you need further whitening gel we can provide this for you at a reduced cost.

How do you do it?

The dentist will take upper and lower impressions of your teeth, this takes about 10 minutes. These are sent to the technician who will construct thin, clear close fitting trays for your teeth. We try these in about a week later and give you the whitening gel in syringes. 

You will be shown how to place the gel in the trays. The colour of your teeth will be recorded. This appointment takes about 20 minutes. You then use your trays loaded with gel for 10 to 14 day sessions or at night until your reach the desired shade. 

Keep any unused syringes of gel in the fridge ideally, you can use these for ‘touch-ups’ at a later date. We will check your shade at your routine examination. Should you have any problems please do not hesitate to contact us.

At our practice we use:

  • ‘at home’ whitening kit
  • in-office’ whitening
  • ‘ultra combination package’

The ‘ultra combination package’ is a system that combines the ‘in-office’ whitening and ‘at home’ whitening to achieve the best results in a short time.

The ‘in-office’ whitening involves a higher concentration of whitening gel being used in the custom made trays which are placed over the teeth and held there for about an hour. The patient is able to relax and close their mouth. The procedure is quite comfortable.

Above all enjoy your bright new smile!


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The team

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Dr. Dipti Lad

Principal Dentist
Dipti qualified in 2003 with an honours degree from the University of Leeds. She gained a distinction in …
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Dr. Myra Ng

Dentist – GDC no. 61143.
Myra graduated in 1986 at the university of Newcastle and since has spent her career mostly in private practice …
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Dr. Savan Zala

MFGDP RCS, MSC Dental Implants
Savan graduated from Guys, Kings & St Thomas’ London in 2004. From an early stage, he adopted …
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Rebecca Gedge

Dental Nurse/Receptionist
Rebecca now local to the area having moved from London where she qualified as Dental Nurse in 2019 …
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Jenni Pattni

Dental Nurse/Receptionist
Jenni Pattni joined in 2021 and has over 15 years dental experience across NHS and private dentistry …

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