Get your smile ready for a close-up.
Your pre-workout smoothie, the berries topping your morning oatmeal, that second glass of red—all those, plus simple aging,
make your smile dingier over time. Bad news for selfies; good news for
the companies that make whitening pastes and strips. But which ones
could work for you, and are there fine-print side effects to watch out
for? For answers, read this guide and get your smile ready for a
close-up.
First, Why Teeth Stain
[post_ads]The outermost surface of your teeth, called enamel, is mostly made up of a chemical called hydroxyapatite and is the hardest substance in your body, says William Graves, D.M.D.,
an associate professor in the department of surgery at Texas Tech
Medical School. "But on a microscopic level it's also very porous, and
over time, stain-causing substances can soak into those pores and
discolor your teeth." The resulting stains, from foods and drinks, are extrinsic, occurring on the surface of the teeth, and sometimes can be removed by just brushing, says Peter Yaman, D.D.S.,
a clinical professor in the department of cariology, restorative
sciences, and endodontics at the University of Michigan School of
Dentistry. Others seep deeper into the enamel and need bleaching to make
a difference. Instrinsic stains refer
to the natural darkening of the deeper layers of your teeth over time,
and whiteners can't do much to help, he says.
OK, So How Do Whiteners Work?
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By
the late 1960s, dentists started to notice a curious side effect in
patients who had been prescribed hydrogen peroxide drops to treat
gingivitis. Not only did their gum disease clear up, but their teeth looked whiter.
Why? Hydrogen peroxide is primarily made of water and a free oxygen
radical. When this free oxygen radical comes in contact with your teeth,
it seeps into the enamel and oxidizes, breaking up stain molecules
lurking inside. Enterprising dentists started experimenting, and before
long, whitening products were born. Today there are three main types of
bleaching: professional in-office procedures, dentist-provided custom
trays for at-home use, and over-the-counter products such as whitening
strips. "All of these work exactly the same way," says Kenneth Magid, D.D.S.,
an associate clinical professor of cariology at NYU College of
Dentistry. "The only differences are how fast they work and how
effective they are against stubborn stains."
While
all bleaching treatments use hydrogen peroxide (or a form of it called
carbamide peroxide), the concentration, which is what determines speed
and effectiveness, varies wildly. In-office treatments pack as much as
35 percent to 40 percent hydrogen peroxide, which could be dangerous in
the hands of a non-pro; at-home products usually max out at 10 percent
to 16 percent . As a result, while many home products can achieve
similar results, they take much longer. (We're talking weeks versus
hours.) There is no shortage of over-the-counter options, but strips—
clear, tapelike stickers that adhere tightly to your teeth— are the
most common. They're good for nearly everyone, except those who have
teeth that overlap. (In that case, the strips won't be able to lie
completely flat in order to make contact with the full surface of the
teeth.)
[post_ads]There are also OTC at-home trays, which you'll fill with a bleaching gel just
before using. The possible downside? They're one size-fits-most,
not all. A more customized option: dentist-provided trays. With these,
you'll visit a dentist to have molds taken of your teeth, then leave
with clear trays built to fit you precisely, as well as a bleaching
solution that's usually stronger than what you can get over the counter.
Custom trays are pricier than the prefab ones— around $250 to $400
versus $50 or less— but usually less expensive than a full in-office
bleaching treatment, which can easily top $500. And the best part:
They're reusable. "Keep the trays stashed away, and next time you can
just buy the whitener from your dentist and reuse them," says Yaman.
What About Safety and Sensitivity?
Dentists
are pretty much unanimous: Whitening is very, very safe. The at-home
kits have too little hydrogen peroxide to do any damage, and while the
concentrations used for in-office treatments are more potent, if you're
seeing a reputable dentist, the risks to your gums
are minimal. There is one unpleasant side effect of whitening that's
pretty common: sensitivity. It occurs when the bleaching material
penetrates an outer layer of the root called cementum, which covers the
nerve chamber of your teeth. Your gums are supposed to protect you from
this, but over time, gums can recede, exposing the vulnerable root
surface. When bleaching solution seeps in, you'll know. "The surface of
your enamel has no feeling, but the surface of the root does," says
Magid. "And the longer you bleach, the greater your risk of
sensitivity."
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Surprisingly,
this is why sensitivity can actually be worse with the gentler at-home
products than with stronger pro treatments. "In-office bleaching takes a
short period of time and the dentist controls where the material goes,
so you might get sensitivity for 12 to 24 hours, but then it goes away,"
Magid says. To minimize contact with your gums and root surface, your
dentist will carefully apply the solution to the teeth and will usually
pack your mouth with gauze or cotton pads during the treatment to catch
any drips. It's nearly impossible to be as careful at home. "With home
bleaching, which can take weeks at a time, you may get bleach all over
your gums and root surface, so sensitivity tends to build," he adds.
Sensitivity isn't dangerous, but as anyone who has ever experienced it will tell you, it hurts. You're much more susceptible to bleach-induced sensitivity if you already have sensitive teeth
or if you've got chipped teeth, receding gums, or worn-down enamel from
grinding. "These underlying factors expose more of the tooth and may
set off inflammation and sensitivity," says Ronald D. Perry, D.M.D., a professor at Tufts University School of Dental Medicine.
When At-Home Bleaching Can't Help
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If
your teeth are more gray than yellow, they won't benefit from the power
of peroxide. (This kind of discoloration is typically a result of the
natural aging process but can also happen if you took certain
medications while your teeth were still developing.) Ask your dentist
about other cosmetic fixes, such as veneers, says Yaman.
Clearly, you've got options when it comes to whitening your teeth.
One of them is deciding that you're fine as is, because no one needs a
new reason to feel self-conscious. And whether or not your teeth are
wedding-cake white, keep smiling. Research shows that a big grin makes you more memorable.
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