Good Question: How Does Teeth Whitening Work?

MINNEAPOLIS (WCCO) – You see the commercials on television and hear the ads on the radio: better ways to whiten your teeth.

A smile is often the first thing you notice about someone.

So it's no surprise that people give special attention to their pearly whites.

Especially as a million dollar smile can be bought for as little as $16.99 these days.

"It used to cost about a thousand dollars to bleach teeth," Dr. Rick Carter said.

Carter has been a dentist for 35 years.

He said over the past 20 years he's watched the teeth whitening phenomenon take off and evolve.

Carter says when dentists first started whitening teeth they used lights.

But it wasn't long before they realized peroxide could whiten teeth and keep them white much longer.

Coffee, tea and tobacco can yellow your teeth, and peroxide works to remove those yellow molecules.

"The peroxides can break that down very easily. So within a day or two your teeth are looking very white," Carter said.

Peroxide is found in a new product called "GO" which Carter uses.

It's basically a mouth guard with whitening gel.

"You can stick it onto your teeth like a mouth guard and it sticks real good," Carter said.

It's also the main ingredient in over-the-counter whitening remedies.

"If you are talking over-the-counter, the white strips work great," Carter said.

But Carter warns not to bleach too much or too long or your teeth can actually darken and turn a bluish color.

He said it's best to follow instructions and consult with a dentist.

"We were surprised because we thought it would be mostly the older people with really dark teeth, but the younger people very much want to have white teeth," Carter said.

Carter said it's also best to brush your teeth with an electric tooth brush or one with soft bristles.

That helps keep enamel intact, which in turn, keeps your teeth looking whiter.