Articles, Blog

What Really Causes Cavities?

August 19, 2019

Did you know that you have whole communities
of microbes living in your mouth right now? And if you don’t treat them right…they’ll
make holes in your teeth. I’m Anna Rothschild, and this is Gross Science. No matter how much you brush, your mouth is
filled with microbes. Thousands of bacteria live on every single one of your teeth—and
that’s if you have excellent oral hygiene! You may even have some fungi and amoebas in
there, too. Which microbes are present changes all the
time, based on, say, who you’re dating. We swap something like 80 million bacteria
with every 10-second-long French kiss, and couples who live together tend to have similar
microbes on their tongues. That said, there is what scientists call your “core microbiome.”
That’s the 150-ish different species of microbes living in most people’s mouths. Now, lots of these guys are totally harmless—and
some are even helpful. For example, some microbes help keep you from getting thrush, which is
a yeast infection of the mouth. Increasingly, we’re learning that to have
a healthy mouth we need healthy microbes, as well. In fact, cavities are a good example
of what can happen when the balance of microbes in your mouth gets out of whack. Many of the microbes living on your teeth
form something called “plaque,” and in small quantities, these guys can be our friends.
Plaque is what’s called a “biofilm”—essentially a community of different microbes that all
stick to a surface—in this case, your teeth. The crazy thing is that these different microbes
talk to each other, passing molecular signals back and forth, and swapping genetic material
to keep on growing. Eventually, the community even develops what you could think of as a
circulatory system to transfer water and nutrients. And speaking of nutrients, the microbes in
these biofilms need to eat, and one thing some of them really love is sugar. So, when
you suck on a lollipop, you’re not the only one getting a tasty treat. After their meal,
these candy and soda-hungry microbes release acid as a waste product. And that acid is
what pulls out the minerals in your teeth, eventually causing cavities. Now, if you stop eating sugary foods and clean
off the plaque by brushing, your teeth have a chance to recover. But if, for example,
you drink soda all the time, the bacteria just produce more and more acid, which not
only causes cavities, but could actually kill off some of the other, good microbes hanging
around. And as the balance of bacteria in your mouth changes, you could get even more
tooth decay and other dental problems. So what can you do about it? Don’t eat too
many sugary foods, remember to brush and floss, and get regular cleanings from your dentist.
Cause we need to keep our communities of microbes happy and healthy. Ew.


  • Reply kawaii Avocado_Dream April 4, 2018 at 11:27 pm

    wowed ????????????

  • Reply XxAMYTHESTxX and XxBLAZExX Gacha April 5, 2018 at 11:43 am

    I just ate snickers no joke

  • Reply Stray Calico Cat April 19, 2018 at 10:10 am

    Lol I’m eating gummy cola now

  • Reply Afez Haikal April 21, 2018 at 11:56 am

    Next time I'm gonna brush my teeth 10 times daily

  • Reply Oceanside Market April 25, 2018 at 3:30 am

    Never french kissing my husband again… Sorry, honey.

  • Reply Amanda April 25, 2018 at 3:58 am

    Slowly puts down soda…

  • Reply QUARTERS-EYE May 5, 2018 at 12:35 am

    You have to stay healthy and eat healthy food like carrots

  • Reply SmoothJess- asmr May 5, 2018 at 6:21 pm

    Slowly spits gum out….

  • Reply Samson Zheng May 7, 2018 at 12:41 am

    et tu brute? : (

  • Reply Lashawn Clarkn May 14, 2018 at 2:30 am

    That scary

  • Reply PokemonAssociate May 14, 2018 at 3:40 pm


  • Reply Ezora Gamer May 24, 2018 at 8:34 am

    I have best friends in my mouth…..COOL!!!

  • Reply ᚢᛁᚫᛁᚾᚷ May 27, 2018 at 4:54 pm

    How can i kill this microbes? I can use rubbing alcohol or what

  • Reply Bhsiao fox Gamer GT May 28, 2018 at 9:59 am

    Wahh eww

  • Reply Emy Just May 31, 2018 at 7:46 pm

    I was just drinking soda and once j heard that plaque leaves acid in my mouth, I stopped drinking..

  • Reply Shayla G June 5, 2018 at 3:01 am

    Vomits up candy……..

  • Reply iShereef - READ MY ABOUT June 8, 2018 at 1:40 pm

    Soo, what happens when a loose tooth infected with a cavity, is removed? Well, there was blood inside.

  • Reply Evislee /Eleanor June 11, 2018 at 9:56 am

    I Hav breathing problems

  • Reply Khloe Lieng June 21, 2018 at 4:31 am

    Is it bad for a cavity tooth to fall out? Do they fall out? What if they do? I have a large cavity, and haven't visited the dentist in a while. It's starting to feel wiggly and I think it'll fall out soon.

  • Reply Ssj Smoove June 22, 2018 at 8:34 am

    I stopped drinking soda brushing my teeth every hour and now im sticking to water I actually ain't candy I stopped eating surgery food all of this is because I have a cavity

  • Reply The Slintea Show June 22, 2018 at 10:04 pm

    I'm a sweet tooth, so when I brush my teeth not as often, I power clean my teeth, but less than around 2 mins.

  • Reply KeatonTheNoob June 24, 2018 at 1:38 am

    One time I had 4 cavity’s

  • Reply Bits with Mits June 25, 2018 at 9:52 pm

    Gross? Its blood mate

  • Reply Oh yeah yeah June 29, 2018 at 7:32 am

    Just drink soda with a straw and make sure it doesnt touch your teeth I do that

  • Reply LogicalLuxury July 6, 2018 at 10:51 pm

    Welp, i got 4 new molars growing in, and my gums are splitting….*my microbes are not happy rn…*

  • Reply Kara Huette July 19, 2018 at 7:34 pm

    Really now I don’t want teeth

  • Reply Niagra falls July 20, 2018 at 1:21 am


  • Reply Pennī July 28, 2018 at 12:20 am

    So if I stop eating sugary foods, my small cavity will recover?

  • Reply Flores G August 10, 2018 at 6:19 am

    I went on vacation for a month and I didn’t have a toothbrush…

  • Reply ALGORITHM KID August 12, 2018 at 2:19 am

    0:11 at first it seems to be like ice cream cone lolzzz XD

  • Reply Todd Sloan August 15, 2018 at 12:05 pm


  • Reply NOAM August 30, 2018 at 12:53 pm

    i didn’t brush my teeth everyday but now … i brush my teeth 5 minutes in the morning on school 5 minutes and at 21:00 5 minutes

  • Reply Iyram Zen September 5, 2018 at 1:20 pm

    Just a quick fact: the teeth are the only organ that can't repair its self.

  • Reply don dupit September 14, 2018 at 1:06 am

    Youre a Rotschilds? Are you the owner of the world?

  • Reply Immy Tan September 15, 2018 at 2:38 am

    You said gross science aa you wrong is not gross

  • Reply lukewalters01 September 23, 2018 at 3:37 am


  • Reply Lena Liu October 9, 2018 at 6:01 am

    I am so prone to cavities…i really should brush 2x instead of once a day ….i had dozens of cavities since 1st grade and i am honestly not a huge candy eater

  • Reply DUAL SQUAD October 13, 2018 at 2:43 pm

    Suddenly put down the cake and just eat a salad

  • Reply leah miller October 17, 2018 at 7:29 pm

    I have been permanently scarred

  • Reply juboraj hossain October 23, 2018 at 1:39 am

    Aww men I was going to get a milk shake

  • Reply Czeska Sinon October 26, 2018 at 7:48 am

    I ain't gonna kiss my boyfriend ever again.

  • Reply The_Other _Seto_Kaiba October 28, 2018 at 8:23 am

    I want to see if she has yeast infection.

  • Reply Darth Lazy October 28, 2018 at 11:18 pm


    Time to start brushing 12 times a day.

  • Reply Violet animations October 29, 2018 at 2:48 am

    Do you know teeth is your bones

  • Reply Abbiebunny Star November 6, 2018 at 10:30 pm


  • Reply Honey Dubey November 10, 2018 at 2:34 am


  • Reply Rainbow Flare November 11, 2018 at 9:32 pm


  • Reply Mason November 12, 2018 at 6:32 pm

    Yes! I'm not alone at night!

  • Reply Leticia Marie Catedral November 14, 2018 at 7:32 am

    I was like When brushing teeth GET OFF CAVITIES and i watched this and mah one teeth hurts and thats why theres BACTERIA.and MAH TEETH BROKE CUZ WHEN IM YOUNG MAH TEETH I FALL MAH TEETH BROKE THATS WHY

  • Reply Roblox Tingz November 17, 2018 at 5:45 am

    brushes teeth while watching video

  • Reply Luna lee November 17, 2018 at 6:44 am

    So wait the bugs inside my mouth are eating my food no way that's my food back off lol

  • Reply Jimins Hijab November 18, 2018 at 4:35 pm

    After this I went and brushed my teeth

  • Reply Mariah Shaw November 19, 2018 at 9:36 pm

    Ok I'm quitting soda a sweets

  • Reply Jeff Love November 21, 2018 at 8:43 pm

    Brushed daily, went to dentist twice a year to get cleaning, still had a mouth full of cavities. Found out my inhaler medication caused me to have my teeth rot out of my mouth. The medication was like glue and stuck to my teeth. I didn't know it then but after loosing all my teeth I read up on my medication that just rinsing out my mouth after using the inhaler would not work you had to vigorously brush your teeth after each use.

  • Reply the art lady December 1, 2018 at 10:53 pm

    I subbed

  • Reply the art lady December 1, 2018 at 10:55 pm

    (read first two words) ?

  • Reply angels are in heaven December 5, 2018 at 3:26 am

    I'm already knowing……I wasn't taken care of my teeth & now I'm starting to lose my teeth….& have wholes all in my mouth

  • Reply OC Madness! Mother-Earth December 10, 2018 at 11:03 pm

    My teeth hurt by looking at the thumbnail.

  • Reply Carrot soda December 11, 2018 at 4:11 pm

    puts candy in trash

  • Reply Artificial Idiot December 13, 2018 at 2:53 pm

    Thought soda have some acid that can decay tooth. So it's the mouth that hurts the moutg

  • Reply Lol Man December 28, 2018 at 4:48 am

    clicks vid brush yo teethies add pops up poop i need to brush but im cozy ugh i would rather not eat than get up

  • Reply Grace99 December 28, 2018 at 9:50 pm

    ah help me please, my cavity is killing me.

  • Reply Mango Productions December 31, 2018 at 6:18 am

    My weird little tooth hanging above my front ensisor got removed by my shirt ?

  • Reply Bharat Patel January 2, 2019 at 8:52 am

    u r a very knowledgeable person.

    love from india

  • Reply juicastace 29298 January 5, 2019 at 5:37 am


  • Reply Ponce Rican January 17, 2019 at 5:19 pm

    Proud of my people, Fernando E. Rodríguez Vargas was an odontologist (dentist), scientist and a Major in the U.S. Army who discovered the bacteria which causes dental caries. He was born in Adjuntas, Puerto Rico.

  • Reply MrPyfisher199 January 19, 2019 at 5:51 am

    Did I just hear funji???

  • Reply IGC_Duck y January 24, 2019 at 6:59 am

    Y u so awesome

  • Reply rmt3589 January 27, 2019 at 6:13 am

    That literally looked like a jelly doughnut on the thumbnail… ew!

  • Reply KelsieAnne :3 February 11, 2019 at 11:26 pm

    Ok… ;-; I think I'm gonna brush my teeth every time after eating BECAUSE OF THIS VIDEO

  • Reply Diane Vu February 12, 2019 at 12:47 am

    How do you know you have cavities? My back teeth are beginning to hurt, but I don’t see any holes or specks. What are the symptoms or development of cavities?

  • Reply Akhrie Pielie February 21, 2019 at 10:42 am

    Watching this with my toothache ??? we should have watch this video when we start going to school

  • Reply Руслан Ибрагимов February 24, 2019 at 4:47 pm


  • Reply donnie mal March 6, 2019 at 3:21 pm

    In the name of Zeus's butt hole I have a tooth ache?? oww

  • Reply KrashSyteGaming March 15, 2019 at 5:32 am


  • Reply Clark Magnuson March 15, 2019 at 5:49 am

    We can tell which indians had corn, as the skeletons have tooth cavities. It is best to be on the paleo diet if you don't want cavities, diabetes, obesity, heart disease, cancer, high blood pressure, etc.

  • Reply RaxaGaming March 26, 2019 at 2:55 pm

    go be cool this littie teethy XDD

  • Reply Jess 456 March 28, 2019 at 2:12 pm

    goes to daddy and tells

    Me:pull my little teeth off
    Dad:ok tomorrow
    Me:dad see this
    Dad:omg tomorrow

    My dad is a dentis

  • Reply Empowered And Overpowered Leftist Black Woman April 5, 2019 at 5:33 pm

    summary: i don't eat trash food, and don't forget to brush your teeth

  • Reply Amari Rodgers April 8, 2019 at 10:50 pm

    I ❤ your vides

  • Reply Joshua Isaac April 11, 2019 at 7:32 am

    Oh so that's why my teeth has holes

  • Reply 銀河の子猫 QweenVenixq 24k April 13, 2019 at 12:57 am


  • Reply StatiC Xtract April 20, 2019 at 4:24 am

    I subscribed even with your questionable last name

  • Reply Kenneth Arcasitas May 12, 2019 at 12:29 pm

    I just got an ad about ice cream

  • Reply Imaspecofdust May 20, 2019 at 12:55 am

    End the sugar rush-

  • Reply Holland C May 24, 2019 at 2:02 pm

    I love you and only because that bill and I already already is the waterI already left this is gray a.k.a. little king and I’m too picky

  • Reply Fenneti Abdukarim May 25, 2019 at 10:28 pm

    The thumbnail looks like a wing

  • Reply Coconutkat uwu June 3, 2019 at 5:14 pm

    Weweewewewewweewewewewewewewewewewewe groosss…..

  • Reply Sebastian DVR June 16, 2019 at 12:54 pm

    throws hershey’s

  • Reply Woolies Thu Le June 22, 2019 at 1:27 pm

    Before video: ad on toothpaste

  • Reply mike the gamer June 29, 2019 at 1:40 pm

    Gross i hate cavity

  • Reply Goku D. Uzumaki July 3, 2019 at 8:39 pm

    Im 11 i have 1 cavity

  • Reply sergio mesmo July 5, 2019 at 2:36 pm

    Dont eat !!!
    And die with all health theeths

  • Reply Adnan in Christ July 23, 2019 at 11:35 am

    Just pull the damn teeth out

  • Reply T-rex Gamer101 July 26, 2019 at 9:03 am

    Gets bottle of bleach

  • Reply Spongie Bobz August 2, 2019 at 6:25 am

    How can. I kill my city in my mouth

  • Reply Bello,Bello Bello Bello August 4, 2019 at 5:45 pm

    Brushing my teeth right now. Than probably throw away soda and hot tamales candy I'm addicted to hot tamale candy

  • Reply King Uno August 13, 2019 at 12:26 am

    I love you Anna… Gross Love???

  • Reply Jiro Pardilla August 15, 2019 at 9:49 pm

    1:03 LOOKED SOO GROSS ???

  • Reply It's Soph • August 18, 2019 at 11:16 pm

    Everyone: goes to brush teeth puts down food

    Me: continues eating salad


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