The Safe Use of Home Tooth Whitening Kits

by Health Canada

Home tooth whitening kits have become very popular with consumers who are hoping to enhance their appearance. When used correctly, they can produce noticeable results.

In the past, most tooth whitening was performed in a dental office by a qualified professional. Today, there are several products available directly to consumers in different applications such as strip, paint-on, or tray kits.

In Canada, all tooth whitening systems (unless they contain fluoride) are considered cosmetics. In terms of regulatory requirements, this means that the manufacturer must submit a cosmetic notification form to Health Canada, accompanied by safety and labelling information. Health Canada does not 'approve' notifications, but submitted information is reviewed to assess that all requirements have been satisfied. Ultimately, the safety of a cosmetic product is the responsibility of the manufacturer.

Home tooth whitening kits are similar to those a dental professional would use, but the concentration of active ingredients are lower than a dental professional's product. Higher concentrations are permitted for in-office formulas because they are applied by a professional who has precise control over the application and understands how it works. A professional can also instruct the consumer on take-home applications and be a direct advisor should an adverse reaction occur.

How Tooth Whiteners Work

Tooth whitening systems use peroxide or peroxide-generating compounds as the whitening ingredient. Most are formulated with hydrogen peroxide, carbamide peroxide or urea peroxide. The latter two are most common, and are about three times less potent than hydrogen peroxide itself.

In general, the more peroxide, the greater the whitening power. Formulations differ depending on the way the product is applied either painted on, as a strip or in a tray. Some products are worn for 30 minutes twice a day, while others are worn all night.

Depending on the strength of the whitener, the peroxide acts on the surface of the tooth, as well as the next layer below the dentin. It does not go far enough to reach the pulp (the innermost part of the tooth).

Tooth whiteners will whiten only natural teeth, not caps, crowns, veneers, fillings or dentures. The results are not permanent, but will last for about six months. The products should not be used more often than every six months.

The Health Risks Of Home Tooth Whitening Kits

Current clinical studies show that home tooth whitening products are not harmful when used as directed. Based on the available scientific information, there is no concern about possible adverse effects on tooth structure or enamel hardness.

However, it is important to follow the instructions on the product and pay attention to any precautionary statements. You should not use the product for more than 14 days without supervision by a dental professional.

Tooth whitening products are known to cause tooth sensitivity in some individuals, although this is usually temporary.

Minimizing Your Risk

Be sure to read and follow the instructions for use shown on the product label.

Do not use a tooth whitening product for more than 14 days without consulting a dental professional.

Should you experience tooth sensitivity, you can try one of these measures, starting with the first.

• Decrease the use of the whitening system to half of the recommended duration. For example, wear it for 30 minutes instead of 60 minutes.
• Discontinue use of the whitener for two or three days, then resume use.
• Stop using the whitener and consult a dentist.

If you've had dental problems, infections or recent work on your teeth, or if you already suffer from tooth sensitivity, talk to your dental professional before using a tooth whitener.

If you are pregnant, have mouth or gum disease or have teeth stained by medication, you should not use tooth whiteners.

In the event of an adverse reaction:

• Discontinue use of the cosmetic.
• Determine whether you should seek medical attention for the adverse effect.
• Keep the product that may have caused the effect at hand. This will enable your medical professional and Health Canada to better help you.
• After medical attention has been sought (if needed), contact your regional Product Safety Office.

Health Canada's Role

Health Canada continues to monitor the information available regarding the safety of tooth whiteners. It examines peer-reviewed, scientific studies from recognized sources, in addition to the safety data submitted by manufacturers. Health Canada also performs product testing when a pattern of adverse reactions to a product occur.

About the Author

www.hc-sc.gc.ca
Health Canada is the Federal department responsible for helping Canadians maintain and improve their health, while respecting individual choices and circumstances.