Did you know that the annual revenue that dental offices rake in for professional teeth whitening is $600 million? It shows how important a bright smile is for most of us, but you may not need to spend big bucks on keeping your teeth white. In fact, you’ve probably heard of some home remedies that rely on fruit and baking soda that are said to work just as well as whitening strips and pricey professional treatments. But if you really want to know the best, safest and most lasting way to keep your teeth white, bright and most of all healthy, results of a study that compared a range of treatments can help you reach for what works best. Plus, our expert, Irwin Smigel, DDS, founder of the American Society of Dental Aesthetics, also weighs in on how to whiten teeth safely and effectively.


A recent study from the University of Iowa College of Dentistry tested a popular home remedy often touted in Internet-based alternative health articles (teeth whitening using pureed strawberries and baking soda)…an over-the-counter product called Crest 3D Intensive whitening strips…an at-home whitening treatment that uses trays that a dentist fits for your teeth called Opalescent PF gel…an in-office teeth-bleaching treatment called Zoom Whitespeed…and plain water and citric acid (as two different placebos). The treatments were all conducted according to the manufacturers’ instructions or suggested use. For example, the “home remedy” involved putting a paste of three level teaspoons of mashed strawberries and one-half level teaspoon of baking soda on teeth for five minutes and repeating that procedure every five days for 15 days, while the Crest 3D treatment involved applying whitening strips to teeth for two hours a day every day for a week.

And for better control of the experiment, the remedies were tested, not on people, but on healthy extracted molars that were stored in artificial saliva and examined several times over a three-month study period. Tooth color was compared against two different professional tooth color-matching tools.

The results: The popular home remedy—strawberries and baking soda—did whiten teeth…a little bit right after use. At one week, one month and three months after treatment, significantly greater color changes were seen for over-the-counter whitening strips, the at-home whitening tray program, and the in-office teeth-bleaching procedure compared with the strawberry concoction (and the placebos). At three months, the greatest color change was seen for the in-office teeth-bleaching treatment, but it wasn’t very different from the results of the whitening strips and the at-home whitening treatment.

At three months, the results for the strawberry and baking soda treatment were no better than placebo, which may mean that the strawberry and baking soda teeth-whitening technique needs to be used a lot more often than used in the study to get more effective results. But Dr. Smigel does not think that this is a good idea. He said that baking soda alone is drying and abrasive…and when it’s mixed with fruit acids (malic acid is thought to be the ingredient in strawberries that helps whiten teeth), damage to tooth enamel can result.

The study concluded that you can get the same or similar results from whitening strips and bleaching trays as you can from expensive in-office teeth-bleaching procedures. That’s great news, but Dr. Smigel had some cautions to share to make sure you do it right.

For one, don’t be a teeth-whitening “junkie.” “Some people overdo teeth whitening, which can be harmful,” Dr. Smigel said. “Teeth can become sensitive and porous and can even chip from excessive use of whitening products. Also, excessive bleaching can cause a permanent translucent, bluish line to form along the tooth’s edge. And this damage can be corrected only with bonding or veneers.” Excessive use of whitening strips can also damage gums and cause severe sensitivity.

Also, think twice before using over-the-counter bleaching tray products. A bleaching tray should always be fitted to your teeth by a dentist, Dr. Smigel said, because ill-fitting trays coupled with loose fillings can allow bleaching material to get in under the filling, causing tooth pain and sensitivity. Patients often use trays longer than instructed to do, which also can damage their teeth and gums—especially if they have receding or bleeding gums. As with whitening strips, the peroxide in the whitener can cause severe gum sensitivity.

Whitening toothpastes can help to whiten teeth. But be sure to avoid any that have silica, Dr. Smigel says. Silica is a type of sand or pumice that your dental hygienist uses during teeth cleaning. It whitens teeth by abrasion. If used regularly, it causes unnecessary wear on the teeth, especially when used with a medium-to-hard toothbrush. (Dr. Smigel sells his own line of whitening toothpaste under the Supersmile brand, and it is silica-free.)