Teeth Whitening Strips
Released on 11/22/2013
[Narrator] If your smile's a bit lackluster,
you could go to the dentist
for a potent blast of tooth-whitening.
But whitening strips put the same ingredients
in a package for home.
What's inside these special strips?
Hydrogen peroxide is the star of the show.
It's the same stuff you bleach your floors with,
but at a much lower concentration.
It breaks apart into radicals,
molecules with reactive, unpaired electrons.
Those guys like to attack stain molecules
and break them apart.
Hydrogen peroxide is an acid,
which is why you need sodium hydroxide,
a base, along with it.
It makes the strip less acidic,
so it's easier to keep in your mouth.
Sodium saccharin helps balance out the bleach, too.
It cloaks the bitterness without cavity-causing sugar.
Then there's the delivery system.
It starts with PEG, or polyethylene glycol.
These chains of carbons and oxygens
love binding to the water in your saliva,
creating a layer of sticky gel.
They also link up at the ends
to other absorbent polymers, including acrylates copolymer.
It's the same stuff that mops up liquid
in disposable diapers.
It takes up so much water that it might dehydrate teeth,
which could be why they're sometimes
sensitive after whitening.
Ouch.
For an extra benefit,
some formulas include sodium acid pyrophosphate,
an anti-tartar agent.
It puts a cap on calcium ions, preventing tartar crystals
from building on top of them.
Now go show off your pearly whites.
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