Putting at-home teeth-whitening to the test

TAMPA (FOX 13) - It can cost a pretty penny to get those pearly whites whiter, especially when it comes to the latest trend - lights. And results aren't always as advertised.

All whiteners rely on one of two active ingredients: Hydrogen peroxide or carbamide peroxide, Tampa dentist Dr. John Redd explained.  "Basically they work inside the tooth and bubble the stains out."

Light is used to speed up their effect. But here's the thing -- dentists use ultra-violent lights to trigger the chemical reaction. Home kits use blue LED's. And there's disagreement over whether they really work.

Amir Shah, owner of Smile Brilliant teeth whitening in Saint Louis, says they originally sold LED kits thinking they were similar to in-office UV whitening, but no longer believes they're worth it.

"It wasn't until I dug into the science a little bit and understood it's a very specific type of light that will actually cause acceleration. You'll see the same kit for $140 and for $30. That's very common and the reason being that light doesn't cost more than a few bucks. It's a basic watch-type battery and a blue LED light. If you take them apart you can see that very, very easily.”

The company now only offers custom-fitted trays and gel, stating on their website that their first-hand experience selling LED whiteners in the past, left them convinced it's, "one of the biggest teeth-whitener gimmicks that has come online in many years." 

"A blue LED may, in some way, may slightly increase the speed of things, but generally it's not going to change it from a one-week process to a one day process."

For better understanding, we went to USF electrical engineer professor Stephen Saddow. He compared the blue LED lights to UV on a spectrum diagram. 

"This is pretty bright and looking at the spectrum here we're going to be almost in the violet," Saddow explained. "Being close to the UV with just a little longer wavelength it will probably have some effective capability. It will just take longer."

His advice to get the most bang for your buck with blue LED whiteners? Don't mix and match because only certain lights work to trigger certain chemical reactions. "You can absolutely tailor the gel to absorb this spectrum and that's what you want to do -- take the same light and use the different whitening compound and maybe it'll work, but most likely it won't."

That's why you'll notice many LED whiteners display right on the box “to be used with" their company's corresponding gel. But some of the cheaper brands say otherwise. And that has Dr. Redd raising the flag.

He says if it advertises that it can worth with any teeth whitening strips or gels, "that means it works without it -- it's a great little gimmick here."

If all this has you considering going back to the basics.  while natural products like charcoal can act as an abrasive to help with surface stains, the American Dental Association says there's no proof of lasting effects. And other popular methods come with their own pitfalls.

One name brand of white strips costs $40.  Then I found one online that was $10. They are both whitening strips. So what's the difference?

Dr. Redd says the higher the concentration of active ingredients, the quicker the results, accounting for steeper prices. But here's where we ran into a problem -- none of the products we bought actually list the percentages.

"Without knowing the percentage, this could be garbage," Dr. Redd offered. "You need to go with a reputable company."

So far, only one over-the-counter-bleaching product has the ADA's seal of approval: Crest 3D White Glamorous White whitestrips.

"I know for a fact that these are 9 percent and these are as high as you can go over the counter," said Dr. Redd. They can go as high as 25 percent in the office.

In-office treatments can range from $600 to $1,000. But the UV light they use is FDA regulated, and takes two hours compared to the several weeks or more it can take at home. But is it really any better?

Dr. Redd says, not really. "The materials in a dentist office will be faster. Not necessarily better."

It's not that over-the-counter whiteners don't work.  But with no FDA oversight and no proof of potency or listing of light-waves, you're entering the wild west of teeth whitening at your own risk.