The truth about tooth whiteners

By: Dr. Samir Patel, Jan 02, 2014

Do the tooth whiteners I see in the drugstore really work?

Do drugstore tooth whiteners really get those pearly whites gleaming?

Dr. Samir Patel answers: Great question. I get asked this question a lot. Tooth whitening has exploded into a multibillion dollar industry. It seems like everyone is doing it. You find it advertised as toothpaste, mouthwash, sprays, strips, paint-on polishes and standalone applications. You find it being performed in mall kiosks, spas, hair salons, independent businesses and in every dental office. It’s just a matter of time before someone comes out with a pill claiming it to be effective in whitening your teeth!

The problem with the whitening phenomenon is that it is flourishing because, for the most part, it’s an unregulated industry. When a product makes a claim to whiten your teeth, in the eyes of the regulators, they are making a cosmetic claim and not a therapeutic one. It’s akin to a make-up company claiming their product makes you more beautiful than their competitors do. It’s all a matter of subjective opinion. Or is it? Fortunately, your local dentist does operate in a regulated field. When he/she performs a service, there has to be a scientific basis for the rationale, effectiveness, and safety of the procedure.

Tooth whitening is not rocket science. If you can remember two simple equations you will be able to make an informed decision on whether a whitening product or procedure is right for you:

Whitening effect = Concentration of peroxide x time of tooth contact
Increased whitening = Increased chance of tooth and gum sensitivity

Firstly, you can see from these equations that if the product doesn’t contain some form of peroxide, it is unlikely to work at all. Secondly, the product has to have a decent amount of time of contact on your teeth to be effective. Therefore, it’s also unlikely to work if the time of contact is a matter of a few seconds to minutes (like toothpastes and mouthwashes). In fact, properly controlled scientific studies have shown that for a group of evaluators to predictably be able to see a difference in tooth colour, you needed to apply, by way of customized trays, a minimum of 10% peroxide to the teeth overnight (eight hours) every night for two weeks. Anything less in concentration or time decreased the consensus in evaluator response. Unfortunately, this regimen was also accompanied by an increase in tooth and gum sensitivity, which are the two main side-effects of tooth whitening. Fortunately, regulators have been wise enough to restrict access to products containing these levels of peroxide to appropriately trained providers like your local dentist who can properly tailor your whitening regimen to maximize effectiveness and minimize side-effects.

Based on this information, you can see that most whitening products sold in your local pharmacy, with a few exceptions, are unlikely to be effective. So next time you choose a toothpaste or mouthwash, choose it because it is the right toothpaste or mouthwash for your oral health, not for its whitening claim. And, as always, you should consult your dentist before agreeing to any whitening procedure.

Dr. Samir Patel graduated from the faculty of dentistry at the University of Toronto in 1993. He also received a bachelor of science and a master of science in microbiology from the University of Toronto in 1987 and 1992 respectively. Dr Patel has been a clinical instructor in undergraduate prosthodontics at the University of Toronto since 2005 and maintains a private practice in Toronto since 1993. He holds memberships in the ODA, CDA and Toronto crown and bridge study club. Dr. Patel is owner of the Lakeshore West Dental Office, in Toronto, Ontario.