A whiter smile can help boost confidence, but it can be pricey.

There are plenty of products on the market promises to make your teeth brighter. But according to cosmetic dentist Dr. Angela Rasmussen, consumers should be careful.

“The concern is, every time you use an abrasive on your tooth, you're removing, eroding a small amount of the enamel surface away,” Rasmussen said. “So if you’re using it over a prolonged period of time, you are going to cause damage to that enamel.”

Your teeth have several layers that affect the color: the enamel is the outer most layer. It’s very porous and becomes stained by the dark colors from beverages like coffee, tea and red wine. The inner most layer is called the dentin. It’s yellow and naturally becomes darker over time.

Whitening toothpaste works because it has abrasives that polish off the surface stains, but it doesn’t change the deeper discoloration of your tooth. Dr. Rasmussen said there’s really only one way to do that.

“You do get a true change in tooth color with bleaching,” Rasmussen said.

Another warning from Rasmussen: Whitening products can cause some irritation to your mouth.

“Your gums could get a little sensitive. Teeth could be sensitive to hot or cold,” Rasmussen said.

Beware if your teeth start to get a grayish hue or if the inside of your lip or cheeks start to peel. That could mean over-use or an allergic reaction. The biggest advice, Rasmussen said, is to use it in moderation.

“I wouldn’t recommend using it as your regular toothpaste,” Dr. Rasmussen said.

Tips to help protect your teeth:

  • Use a soft bristled brush—to minimize abrasion.
  • Don’t use whitening toothpaste every time you brush. Alternate with regular toothpaste
  • Use a toothpaste with fluoride which helps to strengthen enamel.
  • And don’t forget: Get regular cleanings at your dentist’s office.
  • Swish water around in your mouth after drinking coffee, tea, red wine and other drinks that stain.