For most people, brushing their teeth is a
way to keep cavities at bay—with the
pleasant side effects of a brighter smile and
fresh breath. But we've all occasionally
skipped the act before hitting the sack,
whether out of pure laziness or extreme
exhaustion. So how bad is it, really?
The short answer: It doesn't matter if you
brush your teeth right before bed. The most
important thing is that you're brushing your
teeth twice in a 24-hour period, says Kimberly
Harms, D.D.S., a dentist and spokesperson
for the American Dental Association.
film of plaque is constantly building up
thanks to the bacteria that live there, and it
takes about 24 hours to mature. (That fuzzy
feeling in your mouth the morning after you
forget to brush? It's alive!)
The most important thing is that you're
brushing your teeth twice in a 24-hour period.
The bacteria produce acid throughout the
day, and even more when you're eating,
which is why you want to get rid of the film
at least twice per day—any less and the acid
byproducts may eat into your enamel and cause
cavities. The longer the film sits on your teeth
and the more food the bacteria feed on,
the more time you'll spend cringing in the
dentist's chair later on.
Speaking of which, dentists do recommend
brushing when you wake up and before you
go to sleep—for the sake of forming a habit.
(If you simply can't get into bed without
brushing your teeth, you're bound to keep
your mouth clean and healthy.) Plus,
morning-after dragon breath is real, and it can
be scary. Brushing before bed is simply an act
of kindness toward your bedmate and/or
The Snack FactorAs it turns out, brushing in
the space between dinner and bedtime is
technically even better for your teeth than
brushing right before bed. That's because it
gives the fluoride in your toothpaste more time
to strengthen your teeth and build up their
barrier to acid before you go to sleep, says Denis
Kinane, B.D.S, Ph.D, Dean of the University of
Pennsylvania's School of Dental Medicine.
Brushing sometime between dinner and bedtime
is technically even better for your teeth than
brushing right before bed.
But don't head to the bathroom right after you
eat: Dinner is a time of peak acid exposure,
which softens the surface layer of your enamel,
says Greatist Expert Yanfang Ren, D.D.S., Ph.D.
Immediately going at will remove the softened
enamel and cause erosive tooth wear, so wait at
least 30 minutes after dinner before you brush
up. And avoid snacking after that—bacteria
feeds off of any carbohydrates (we're not just
talking about bread, they're in nearly every food).
The absence of our antibacterial saliva at night
means we're extra vulnerable to cavity-causing
agents and gum disease, Harms says, but don't
stress if you forget to brush every once in a while.
Ren says it takes a long time for plaque to calcify
(a fancy way to say "turn dangerous"), and
brushing enough should remove day-old plaque--
just up your brushing time from two minutes to
four, and you should be good.
Ingesting carbs constantly throughout the day
also leaves people more prone to cavities. "If you
snack all day long, the bacteria wake up and start
producing acid every time you ingest any type
of a carbohydrate," Harms says. During a typical
meal, your saliva levels are higher, working to
protect your teeth and aid in digestion. But as
you graze throughout the day (or even slowly
sip a cup of coffee), those repeated "exposures"
to food give bacteria a meal every time, leading to
more acid on your gleaming teeth.
The most important thing to remember:
it doesn't matter exactly when you
brush your teeth, so long as you head into the
night without bacteria (and the food they feed
on) in your mouth. Just be sure to brush again
in the a.m. and floss to get the bacteria out from
between your teeth. And try to cut back on
constant snacking—and maybe that second cup
of coffee—to avoid feeding the mouth monsters