Health: The white stuff

Trying to add a bit of sparkle to your pearly whites can be confusing and expensive. Will over-the-counter whitening strips or toothpastes really work? Or should you splurge and pay a dentist for professional teeth whitening services?

First, make sure you have realistic expectations, says Dr. Laura Tam, professor of restorative dentistry at the University of Toronto. Whitening can cause sensitivity in the teeth and gums, and it doesn’t work on stained or dirty teeth. Also, most dental work, such as bridges, crowns and partials cannot be whitened—and can even be damaged by bleaching agents.

Be sure to ask your dentist before pursuing any teeth whitening option. “A healthy mouth is paramount before starting any cosmetic service,” explains Dr. Joel Antel, president of the Manitoba Dental Association.

Here’s a look at the most popular choices:

Bleaching gel trays ($200- $400): With this option, a dentist takes an impression of your teeth and gives you a custom-fit plastic tray along with a supply of bleaching gel. For the treatment to work, you’ll need to sleep with the tray and bleaching gel in your mouth every night for two to six weeks.

With professional results and excellent value, this is the best option for most people, says Tam—if you can put up with the inconvenience. “This treatment is considered the most effective according to numerous studies.” That’s because the trays give your teeth the longest exposure to the bleaching agent. Another advantage is that it works well for people with misaligned teeth.

It will take three to five days before you notice a difference, but the results can last one to three years.

Laser treatment ($4,000-$5,000): Laser treatment is an in-office procedure that is fast and effective, but very expensive. It works by applying peroxide and then using a laser to bleach your teeth.

The major advantage is that the results are instantaneous. But there’s no evidence that the results are any better or longer-lasting than bleaching trays. Also, studies show an even higher rate of tooth sensitivity, explains Antel.

Light therapy ($500-$5,000): Similar to laser treatment, light therapy works by applying peroxide and then using light to activate the whitening process. But unlike laser treatment, light therapy services can be found at your local spa or esthetic clinic—at a fraction of the cost.

Dr. Annie St-Georges, professor in the Faculty of Dentistry at the University of Montreal, warns against these cheaper options. “The peroxide used in these facilities is often poorly applied, and in a significant number of cases causes sensitivity in the teeth and gums.”

With light therapy you can expect instant results, but they’ll be no better than the less expensive bleaching gel trays.

Whitening toothpaste ($2-$10): Tam stresses that these toothpastes are effective at removing stains, but that’s not the same as whitening. “To whiten teeth a product must use a bleach, and these toothpastes don’t. Instead, they use enzymes.”

However, because teeth need to be free of stains for whitening to be effective, these toothpastes can be a good first step.

Whitening strips ($16-$40): The active ingredient in this over-the-counter treatment is similar to the one used in professional procedures. Most of the kits require you to attach a one-size-fits-all strip and keep it on your teeth for 10 to 30 minutes.

This method is generally very effective, says Tam, “particularly if you have well-aligned teeth and don’t require customization.” Unfortunately, there are no studies that show how long the effects can last. “You can get results with this approach,” says Tam, but you shouldn’t use the strips more than once every 12 months.