Tooth whitening and bleaching

published December 23rd, 2011

Enjoy your bright smile!

Patients are very interested in whitening teeth. This is because appearance is important to them and they realize that the mouth and their smile is the focus of considerable attention, as we go through our daily routines.

If we feel good about our appearance we feel good about ourselves. These good feelings in turn result in better relationships with those around us.

Bleaching procedures are not new in dentistry. Many techniques have been developed by dentists to lighten the shade of a patient’s teeth. In the past, treatments were done in the dentist’s office. Most methods involved isolating the teeth and sealing them off from the remainder of the patients mouth. This was necessary because strong hydrogen peroxide solutions, heat, and light were used to bleach the teeth. The large amount of time involved made the procedures costly. The results were generally good but one major problem existed. The teeth would return to their former shade in 3 to 6 months. The process would have to be repeated again, with another charge incurred. Needless to say few people had their teeth bleached.

Current techniques are usually done by the patient at home. Much milder methods are used which are much gentler and easier to control. Instead of attempting to bleach the teeth in one session at the dentist’s office, the process  takes 2-3 weeks and is done at home with supervision and instructions provided by the dentist. This technique utilizes a vacuum formed plastic device, called a tray, that holds the bleach in contact with the teeth. The bleach is still basically hydrogen peroxide based. Usually the chemical used is carbamide peroxide which breaks down to hydrogen peroxide after it is applied to the tray and teeth. The results are quite similar to the former in-office treatments but the advantage is that, periodically, every 3-4 weeks, the teeth can be retreated, at home, by the patient, with no additional cost or bother to the patient. This periodic re-treatment maintains the desired color and shade. Bleaching can remove many stains that are in the outer layers of your teeth. Teeth tend to change shades, usually yellow, with age. These changes can be reversed. Stains in the grey family (such as tetracycline) can be more stubborn, if not impossible, to bleach. Usually, we cannot predict the effectiveness of bleaching for each individual patient. Bleaching must be tried first to see what degree of bleaching is obtainable. Bleaching will not change the colour of existing dental restorations. If restorations are planned for the anterior part of the mouth it is advisable to accomplish the bleaching first, then match the new restorations to the now bleached teeth.

So, What do you need to do next if you want to have your teeth bleached and whitened?

First of all, your dentist should examine all of your teeth and determine the health of your mouth. After treatment plans are made and you are ready to go ahead with bleaching, the dentist will need to take moulds or impressions, of your teeth. These moulds are used to make the custom vacuum formed trays to hold the bleaching agent against your teeth. After the trays are made they will be tried in and adjusted. You will be given instructions for wearing the trays and how to apply the bleach. Usually, you will be returning to the dentist office for a visit to review your progress and determine the response of the teeth to bleaching and any side effects. There are a few side effects that you need to be aware of. In our Clinic, we have a printed sheet of the side effects that you may experience. As with any procedure we can have problems which vary with each patient. The most common side effect is sensitivity of the teeth and gums. This can be controlled by fluoride mouth rinses, and the use of  Sensodyne (TM) or another desensitizing toothpastes. Usually, by cutting down the time of bleaching this problem can be controlled. Many times breaking up the amount of time bleaching is done into smaller, longer spaced segments, will alleviate the sensitivity problem.

Another problem is sometimes the wearing of the tray makes the teeth tender to biting pressure. This can happen when the original impression was distorted in some manner. This results in an inaccurate model. When the tray is vacuum formed to fit the model the inaccuracy is reproduced and when the trays are placed in the mouth they act like weak orthodontic appliances which result in sore teeth. The trays will probably have to be remade.

Other effects of bleaching are really not known facts. We have used hydrogen peroxide for years as a mouth rinse and we have seen no apparent problems with its use. In all honesty, we can’t say for sure that its use will not cause harm to the teeth or gums that become apparent years from now. All we can say is that we suspect no long term problems will exist.

What, if any, are the contra-indications for tooth bleaching? And which people should not have any bleaching process carried out? As of this writing we would not recommend bleaching for smokers. Smokers should stop smoking before having their teeth bleached. The smoking not only defeats the effect of bleaching but some authors are concerned about the mixture of hydrogen peroxide with smoking having a potentiating effect on tissue damage already known to be caused by smoking. As far as we are aware, pregnancy and other diseases are not a contra-indication.

So I have now decided to have my teeth bleached, I have my trays what now? Brush your teeth before putting in your bleaching trays. Apply a small amount of the peroxide based gel provided into the tray and insert into your mouth. Don’t try and eat or drink while the trays are in your mouth. After about one hour of wear replenish the bleach in the trays and replace them in your mouth. We recommend that our patients wear the trays about 2 hours per day for 2-3 weeks. The hours do not have to be continuous. After removing the tray and discontinuing bleaching rinse your mouth. Avoid citrus fruits and other acidic foods while in the process of bleaching. They may contribute to sensitivity, and there is concern that the fruit acids may cause damage to the outer tooth surfaces.

After the first 3-4 weeks your teeth are probably bleached as much as possible. The time it takes for you to attain the colour and shade that you want, is very variable. The longer you wear the tray and the bleaching gel, the quicker the effects will be. But you have to balance this with the degree of sensitivity you may have. From here on out just renew the bleaching every 4 weeks or so by wearing the tray with bleach for 2 hours. Above all enjoy your bright smile!

For a permanent change, you should consider the placement of Veneers, and you can access this information from our Patient Information pages.

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