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Dental Blog & Advice

Questions about teeth whitening

Patient information on teeth whitening

If you would like your teeth whitened, one of the best systems available is the take home kit. The dentist will check if your teeth are suited for whitening and if there are any issues which need to be addressed. For example, any fillings on front teeth will not whiten and you will more than likely be required to have these replaced to match the colour of your new smile.

One of the tried and tested systems we have been using for a while is the patient take home kit. It is effective, economic, reusable, low maintenance and you control how white you would like your teeth to be.

The procedure

  1. The dentist will need to check if your teeth are suited for the teeth whitening procedure.

  2. If you are an ideal candidate then some special moulds will need to be taken of your teeth.

  3. You are required to book another appointment. On this second appointment, the dentist will fit the special trays to make sure they fit accurate over your teeth. You will be shown how to use the gel.

  4. It is preferable to keep a daily log of when you use the gel. A log sheet will be supplied to you.

  5. The dentist may take some photographs to get a baseline record of the colour of your teeth before you start the treatment.

  6. You may be asked to come in for a review appointment which will give everyone a chance to assess if the whitening has worked and answer any of your queries.

Does teeth whitening work?

Once the dentist assesses your teeth he will tell you if your teeth are suited to be whitened. From experience:

  • 90% of patients who have the procedure respond well.

  • 5 % don’t respond initially to the gel. For this reason they need to use the gel for a longer period or try out another gel.

  • You may be in the 5% category of a “non-responder”. This means you have tried all means to whiten your teeth but your teeth are very resilient to change. This is a small risk which patients have to accept when they undergo the teeth whitening programme.

What about power /laser whitening?

We have used this technique a lot in the past with varied results. The way this treatment works is that along with the power whitening gel you get dehydration of the tooth enamel. This gives the teeth the appearance of appearing whiter. This is a temporary treatment when used alone; however, the patient will still need to maintain their new smile with the home kit system.

Power whitening can result in sensitivity for some patients. We mainly use the home kit system, as it is the tried and tested safe method.

As a general rule, the slower your teeth whiten the better the results. Gentle whitening is better than power whitening.

Is teeth whitening safe?

  • It is a safe procedure, only if carried out under the instructions of a dental professional.

  • It does not damage your teeth or gums if you follow the advice.

  • Just to safeguard your health and that of your baby’s we do not recommend the procedure to be carried out for pregnant or nursing mothers.

  • It is illegal for a non-dental professional to carry out teeth whitening procedure or even to examine your teeth.

  • Do not buy teeth whitening product over the internet. These most likely will be unauthorised dealers and may contain dangerous levels of chemicals. Teeth whitening can only be prescribed by a dentist after he deems your teeth suitable for the procedure.

What am I to expect after whitening my teeth?

For a few days after you use the gel in the trays you may not notice any difference but your teeth may feel “tingly” or slightly sensitive. Don’t worry, as the sensitivity is transient and it is explained later how to deal with the sensitivity. In fact, if your teeth do become sensitive it mean the gel is working its way into the tooth and you should see some results within a few days.

Different teeth respond at different rates. If your teeth are not too yellow then you may see results after day 3. Darker teeth can even take over 2 weeks of daily whitening before you see any visible changes. Generally speaking, the darker the teeth, the longer they will take to whiten.

Once your teeth whiten, do not stop using the kit. Continue whitening them. Use the gel trays for a few more days just to maintain the colour.

What maintenance do I need?

  • Regular hygiene cleans and check ups

  • Once you have completed the two week cycle (or longer in some cases) and your teeth have whitened then all you need to do is monitor the colour of your teeth. You will get relapse of the colour, i.e. the colour of your teeth will try to get back to normal. This is dependent on the quality of your enamel and the amount of coloured foods you consume. You may need to top up the tooth gel once every month or every two months or when you have a special occasion.

What are the risks of teeth whitening?

  • Your teeth may fall into that last 5% bracket whereby they don’t whiten at all.

  • Teeth whitening is not permanent. You will get relapse. For a more permanent white smile you will require to have an assessment for porcelain veneers. Porcelain veneers changes the colour, shape, size of your teeth and in some cases can even straighten your teeth.

  • You may notice white specks on your teeth. As the whitening progresses, these white specks blend usually blend into the overall shade. Sometimes, these white specks can appear more prominent; if they do then it is up to you if you wish to continue with the whitening. Excessive white speck can be eliminated by adjucnt whitening procedures or composite bonding (white fillings)

  • Teeth are not made up of a single colour. If you took a picture of your tooth with a high quality camera and enlarged it on a big TV screen then you will see many shades and textures within the same tooth. After the whitening programme, a single tooth may change colour at different rates. If you look at this single tooth close up then you may see some areas which appear brighter within the same tooth. This is very subtle and can only be seen from a close up position and may appear as small white flecks.

  • The good thing about the home kit is that the patient controls how white they want their teeth to become according to how long they leave the gel on the tooth for. If you don’t like the colour of your new smile then you can stop the whitening and enquire about other options (e.g. porcelain veneers).

  • Sensitivity. This is transient. We will explain to you how you can deal with this to minimise it.

  • Teeth whitening does not whiten fillings or crowns. For this reason you may decide to whiten your teeth and then change the fillings and crowns once a stable whiter colour has been achieved. If you do want to change your crowns for a more aesthetic smile, it is best to whiten your teeth first.

How long do I leave the trays in my mouth for?

It all depends on your sensitivity levels and how long you can cope with them in your mouth. We usually recommend 3 hours every evening or overnight wear. The longer you leave them in, the more effective the gel will be.

You need to use them daily over a 2-3 week period. Don’t worry if you skip a day, but try to keep it constant. Refrain from eating and drinking heavily coloured products (e.g. red wine, curry).


How to deal with the sensitivity

Different patient have varying sensitivity levels. Most patients experience zero sensitivity. Sometimes the dentist can tell if a patient is more than likely to experience sensitivity.

Desensitise your teeth them with the following method:

  • Brush and floss regularly as bad gums can be a precursor to sensitivity.

  • Use anti-sensitive toothpaste such as Sendodyne Total Care or Sensodyne Pronamel.

  • Use anti-sensitive mouthwash twice a day: rinse for one minute and spit out.

  • For 2-3 day prior to starting your whitening, put the anti-sensitive toothpaste in your trays and leave them in your mouth for 30 minutes. Do this every evening for 2-3 days.

  • When you whiten your teeth and take the trays out of your mouth, wash the trays with cold water and brush your teeth. If your teeth are sensitivity after removing the trays then put the Sensodyne into the trays and fit them over your teeth. Leave for 30 minutes. Take out the trays and brush your teeth. Use the mouthwash.

  • If your teeth are very sensitive, then you can skip a day. You can also leave the trays in your mouth for less time. Look at your log.

What if I run out of gel?

  • You should aim to get 3-4 days use out of each tube.

  • You can purchase new gel if the dentist thinks it is suited to you. It costs £10 per tube or £30 for 4 tubes. The take home kit is a very cost effective method for the patient to enhance the appearance of their smile.

  • The dentist needs to examine your teeth before prescribing you the gel.


Try and refrain from using teeth whitening toothpastes. Although these may get rid of gentle stains, they do not whiten teeth. A lot of patients complain of sensitivity which is simply resolved by them stop using this type of toothpaste.

100% Guaranteed Permanent teeth whitening

For a permanent white smile, the best course of action is to have a consultation for porcelain veneers. Instead of looking “Tip-Ex” white, your smile can be made to look as natural as possible and the patient can choose the colour and characteristics of their new teeth. Minimal preparation porcelain veneers can strengthen the teeth in some cases. Please ask the dentist.

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