Are whitening strips from the pharmacy safe?

Over-the-counter whitening strips are generally lower in strength than the products a dental professional uses, so they work more slowly and produce a smaller change. Used exactly as directed, they are not automatically unsafe, but incorrect or excessive use can irritate the gums or affect the enamel, and a strip cannot assess existing fillings, crowns or the cause of your own discolouration. An examination first is the most reliable way to know whether whitening suits you.

In short

• Whitening strips and kits sold over the counter contain a lower strength of whitening ingredient than a dentist uses, so results are generally slower and less noticeable.
• The South African Dental Association’s own patient guidance advises against relying on these products, since they can cause gum irritation and sensitive teeth if used incorrectly or too often.
• A strip whitens only natural tooth enamel, so it cannot tell you whether discolouration has another cause, or whether you have decay or gum disease that needs treating first.
• Existing fillings, crowns or veneers will not change colour with any whitening product, which can leave an uneven result.
• An examination by a dentist, dental therapist or oral hygienist beforehand is the most reliable way to know whether whitening is a good option for you.

This article is part of the teeth whitening information on this site for patients in Cape Town.

How do pharmacy whitening strips work?

Whitening strips use a gel, generally containing a lower concentration of hydrogen peroxide or carbamide peroxide than a dentist would use, applied directly to the teeth on a thin, flexible strip. The peroxide works through the enamel to lighten the colour underneath, similar in principle to professional whitening but at a gentler strength. Products sold over the counter are not permitted to be as strong as those used by a dental professional, so they tend to work more slowly, or need more frequent use to reach a similar result.

Are they actually safe to use?

Used exactly as directed, over-the-counter whitening products are not automatically unsafe, but the South African Dental Association’s own patient guidance advises against relying on them, since a weaker product used more often can lead to gum irritation and sensitive teeth, and incorrect or excessive use can affect the enamel. This is one of the reasons dentists generally recommend planning any whitening, even a pharmacy product, around a dental examination, described more on the teeth whitening service page. Some temporary sensitivity to hot or cold is common with any whitening product, similar to the sensitivity some people notice after a filling, covered in Is it normal for a tooth to be sensitive after a filling?, and this is usually mild and settles within a few days.

What can a strip not tell you?

A whitening strip cannot examine your mouth. It does not check for decay, gum disease, or existing dental work that could be affected, and it cannot explain why your teeth are discoloured in the first place, which sometimes has a cause, such as an old injury or a previous root canal, that plain whitening will not address in the same way. Existing fillings, crowns or veneers will not change colour with a whitening strip, or with any whitening product, which can leave a mismatch between whitened natural teeth and unchanged dental work. Can crowns, fillings or veneers be whitened? covers this in more detail.

Is a professional option different?

An examination beforehand, whether you choose a pharmacy product or professional whitening, is the most reliable way to know if whitening is right for you and to plan around any existing dental work. In South Africa, a whitening procedure carried out in a dental practice may only be performed by a dentist, dental therapist or oral hygienist, after a clinical examination. A dentist can also explain what professional whitening involves and costs, so you can weigh it up against a pharmacy product.

How do I reach Dr Davies?

To ask whether whitening is suitable for your teeth, call Dr Davies directly on her own mobile, which is shown on this page. You can also ask for an appointment through this site. Dr Davies provides teeth whitening at BRS Dental on Strand Street, in Cape Town City Centre, and this page gives general information rather than advice on your own teeth.