Wednesday, April 2, 2025
HomeOral Health & HygieneWhat Causes Cavities?

What Causes Cavities?

If you’re like most people, you may believe that sugar causes cavities.  After all, candy is bad for our teeth, right?

Sugar doesn’t cause cavities.  In fact, this has been known for over 50 years!

In 1954, a man by the name of Frank Orland wanted to see if sugar caused cavities.  He conducted a pioneering research study, in which he raised 22 rats in a sterile environment.  From birth ’til death, these rats never had any contact with any germs.  He fed these rats lots of sugar throughout their entire life.

Guess how many of these rats that ate sugar every day ended up getting cavities?

Zero.

None of the rats that were raised “germ-free” got any cavities even while they were eating all of the sugary foods that they wanted.  In contrast, 38 of the 39 rats that ate the same foods but were not raised “germ-free” ended up getting cavities.

Part of his conclusion states, “Findings indicated that twenty-two rats reared under germfree conditions remained entirely free of even microscopically demonstrable dental caries. Of thirty-nine conventional control rats, possessing the usual mixed microbial populations, thirty-eight developed various lesions when maintained on the same kind of dietary regime as the germfree animals. It is deduced from this evidence that dental caries in the rat is not possible in the absence of microorganisms.”

If you only looked at Dr. Orland’s study, you may be tempted to say that it must be bacteria, and not sugar, that causes cavities.

More recently, other studies have shown that it’s possible for rats with bacteria to not have any cavities if they are not fed sugar or fermentable carbohydrates.

These studies lead us to believe that bacteria and sugar must be present in order to get cavities.  But even these two elements don’t account for the whole picture.

For example, my wife never had a cavity in the first 25 years of her life.  Like most normal people, she ate sugar and had bacteria in her mouth.

So, what really causes cavities?  There are actually four components that, when present together, cause cavities:

What Causes Cavities?

In order to get cavities, you need to have four main ingredients:

1 – Sugar
2 – Bacteria
3 – A Susceptible Tooth
4 – Time

You can take a look at this relationship in the diagram below.  If you’re interested, you can then read about how you can use this information to prevent cavities.

4 Causes of Cavities & Tooth Decay

 

1 – Sugar

For simplicity’s sake, I labeled this category as sugar.  In reality, it could be called refined carbohydrates because anything that can be broken down into sugar inside of your mouth is able to feed the bacteria that contribute to causing cavities.

For example, potato chips are made of a simple starch that can be broken down into sugar by enzymes that are found in your saliva.  How often you eat sugar is more important than how much sugar you eat in one sitting.

To learn more, read What Happens In Your Mouth Every Time You Eat or Drink, What Fermentable Carbohydrates Are & How They Hurt Your Teeth, and 50 Names for Sugar that Food Makers Use to Trick You.

2 – Bacteria

Bacteria live inside all of our mouths (unless you’re one of the rats in Dr. Orland’s study!)  It’s really fascinating to me that there are millions of little creatures living inside of everyone’s mouth — this is what first got me interested in dentistry and was the subject of my first article here at Oral Answers, What Every Human Needs to Know About Plaque.

While you can’t completely rid your mouth of all the bacteria, you can destroy the homes they build on your teeth every time you brush and floss.  By regularly brushing and flossing, you can help win the fight against the bacteria in your mouth.

3 – A Susceptible Tooth

Many people who have had their share of cavities say that they have soft enamel or that  bad teeth run in their family.  While there’s no such thing as soft enamel, people can have enamel that may not have been formed correctly.  Also, bad teeth aren’t genetic, but some people’s teeth do have deeper pits and grooves than others.

These pits and grooves can be so deep that even a bristle on a toothbrush can’t reach down to clean them out.  In these cases, these people will almost always get cavities unless they have had sealants placed on these teeth when they were kids.

There are many other factors that influence how susceptible a tooth is to getting cavities.  I will only go over a few of the more common ones.

The first is the quality and amount of the dental enamel.  Pinkham’s Pediatric Dentistry text states that enamel hypoplasia (when not enough enamel forms), even at levels that are undetectable,  increases susceptibility to tooth decay.

Saliva also plays an important role in how susceptible a tooth is to decay.  The more saliva you have, the better.  To learn more about the role that saliva plays in your oral health, read How Saliva Protects Your Teeth and Six Main Causes of Dry Mouth/Xerostomia.

The last factor I will discuss that makes your tooth more susceptible to cavities is the wearing away of tooth structure.  This commonly occurs through the process of acid erosion, which can occur by drinking these nine teeth-dissolving drinks, however there are four ways that you can wear away your teeth.

4 – Time

Darius Rucker sang the following words Hootie & The Blowfish’s hit Time back in the 90’s

Time, Why you punish me? Like a wave crashing into the shore, you wash away my dreams.

Time can in fact wash away your dreams of having healthy teeth if you give the bacteria enough time on your teeth.  In fact, you can have all three elements above and not get cavities if you don’t give the bacteria time to eat away at your tooth.

Plaque eats sugar, which produces acid that slowly eats away at your susceptible teeth.  The key is to not give the bacteria enough time on your teeth.  You can do this by brushing and flossing regularly.

To learn more, read the article Try to Keep Your Teeth Below Freezing.

Conclusion

Cavities don’t just happen spontaneously.  You need four things to get cavities: sugar, bacteria, susceptible teeth, and time.

You can’t really control the bacteria unless you live in a sterile environment.  You also can’t control the genes that sculpted your teeth into their exact formation that might make them hard to clean. You can control how much sugar you eat, your oral hygiene, and how well you treat your teeth (don’t treat your teeth like tools!)

Do you have any questions, stories, comments, or concerns about what really causes cavities?  I’d love to hear them in the comments section below.  Thanks for reading!

RELATED ARTICLES

3 COMMENTS

  1. I read that babies are born without the oral bacteria that cause cavities, and that it is through other people (usually parents sharing food or blowing on food to cool it) that they end up with those bacteria in their mouths. Of course, I suppose there is really no way around that!

    • Hi Rachel – We did talk about this in our pediatric courses. Babies are born sterile and they do end up picking up all of the bacteria from their surroundings. Now that I have kids, I do think it’s nearly impossible to not share our bacteria with them!

LEAVE A REPLY

Please enter your comment!
Please enter your name here

Most Popular

Recent Comments

kathrine Schwab on Ten Causes of Canker Sores
Rosemary Peter on Ten Causes of Canker Sores
Preston Essic on Dental Patient Rights
Rich Valentino on Dental Patient Rights
Thandolwethu on Teething Baby Pictures
Erin Knutson on Ten Causes of Canker Sores
Kirstie Feyerabend on Can You Keep Your Extracted Teeth?
Robert McKnight on Colored Fillings
Queen Kay (AKA Kaleigh) on 60 Photos of Teenagers with Braces
Carolina on Do Braces Hurt?
Onelesstoothtocompletemysmilebonescollection on Can You Keep Your Extracted Teeth?
Marianne Sites on Colored Fillings
lulu on Do Braces Hurt?
David Abarientos on How Long Does Teething Last?
Shouganai on Colored Fillings
Benjamin Greene on Dental Patient Rights
Laura elliott on Teething Baby Pictures
David Plaster on Ten Causes of Canker Sores
any intelligent mind. on Seven Ways Meth Ruins Your Teeth
Maria on Do Braces Hurt?
Karina on Do Braces Hurt?
Collette hunt on Ten Causes of Canker Sores
Megan on Do Braces Hurt?
A Person (I wish to remain anonymous) on Can You Keep Your Extracted Teeth?
Alison M. on Do Braces Hurt?
Mandarinboop on Do Braces Hurt?
kaito on Do Braces Hurt?
kaito on Do Braces Hurt?
Fidel Márquez Avilés, DDS, MSD on A Trip to The National Museum of Dentistry
Imogen on Do Braces Hurt?
14 year old teenager on 60 Photos of Teenagers with Braces
Dr. Todd Donnelly, D.D.s on What’s In an Amalgam Filling?
Rayna on Do Braces Hurt?
Sarah Kollmansberger on Why Your Dentist Can’t Get You Numb
Ana Howard on Do Braces Hurt?
Ana Howard on Do Braces Hurt?
estrella.reyes on Do Braces Hurt?
Mr. Unidentified Internet creature #3.14159265359 on Seven Ways Meth Ruins Your Teeth
Aisha on Do Braces Hurt?
Charlotte Creasy on How Long Does Teething Last?
Liza on Do Braces Hurt?
Maylin on Do Braces Hurt?
Stella on Do Braces Hurt?
Jim Bon - Muhammad on Six Reasons Why Your Crown Fell Off
Michelle on Colored Fillings
Floyd Mayweather on Seven Ways Meth Ruins Your Teeth
Abigail Rose Mounteney on Do Braces Hurt?
30 years of ice chewing on How Chewing Ice Cubes Hurts Your Teeth
Shawn on Do Braces Hurt?
Jess on Do Braces Hurt?
Jess on Do Braces Hurt?
Rebekah on Do Braces Hurt?
Coooooookie on Do Braces Hurt?
Sydney on Do Braces Hurt?
Sydney on Do Braces Hurt?
Francisco Mayorga on What’s In an Amalgam Filling?
Natasha on Do Braces Hurt?
kahalia on Do Braces Hurt?
nicole on Do Braces Hurt?
Mirah on Do Braces Hurt?
Adesola Adebayo on Double Tooth Photos
kathleen on Do Braces Hurt?
Winny on Do Braces Hurt?
Summer on Do Braces Hurt?
Need a Dental Expert Report on How to Really Win a Dental Malpractice Lawsuit
star on Do Braces Hurt?
star on Do Braces Hurt?
Brandon on Do Braces Hurt?
Joselyn on Do Braces Hurt?
Grace on Do Braces Hurt?
Kimberly on Do Braces Hurt?
Bobbo Jones on Privacy Policy
Alana on Do Braces Hurt?
Sarah on Do Braces Hurt?
Neha on Do Braces Hurt?
Neha on Do Braces Hurt?
Cansas on Do Braces Hurt?
Misha on Do Braces Hurt?
Suppp on Do Braces Hurt?
Sophie on Do Braces Hurt?
Nicky on Do Braces Hurt?
Destiny on Do Braces Hurt?
Destiny on Do Braces Hurt?
Jaine on Do Braces Hurt?
Sophi on Do Braces Hurt?
Monique on Do Braces Hurt?
Ivan on Do Braces Hurt?
Ivan on Do Braces Hurt?
Jaclyn:))) on Do Braces Hurt?
Helena on Do Braces Hurt?
Helena on Do Braces Hurt?
Caitlin on Do Braces Hurt?
Sanah on Do Braces Hurt?
Sanah on Do Braces Hurt?
Sanah on Do Braces Hurt?
Janine Holder on Do Braces Hurt?
Julie on Do Braces Hurt?
Syaza on Do Braces Hurt?
Syaza on Do Braces Hurt?
Chris on Do Braces Hurt?
Torii on Do Braces Hurt?
jesse on Do Braces Hurt?
Kool on Do Braces Hurt?
Bree on Do Braces Hurt?
Sheep on Do Braces Hurt?
Savannah on Do Braces Hurt?
Taije on Do Braces Hurt?
Taije on Do Braces Hurt?
Taije on Do Braces Hurt?
Taije on Do Braces Hurt?
Beauty (NOT a Beast) on Is Sparkling Water Bad For Your Teeth?
Geckonator on Do Braces Hurt?
nichole on Do Braces Hurt?
Yolie on Do Braces Hurt?
Teeth? on Do Braces Hurt?
susan on Do Braces Hurt?
Alexis on Do Braces Hurt?
ScaredGirl on Do Braces Hurt?
Josephine Wadlow-Evans on Dental Suction: Why Dentists Use a Suction
Rayeed on Do Braces Hurt?
Mary on Do Braces Hurt?
Jazlynn on Do Braces Hurt?
Happy after all on Do Braces Hurt?
CHughey on Do Braces Hurt?
Rachel on Do Braces Hurt?
A Peer-Review Dentists Wife on An Alternative to Suing Your Dentist: Peer Review
maddy on Do Braces Hurt?
shahd on Do Braces Hurt?
shahd on Do Braces Hurt?
Hermionefan on Do Braces Hurt?
ashika on Why Teeth Hurt
Sally on Do Braces Hurt?
Kelli on Do Braces Hurt?
Brittani on Do Braces Hurt?
NewDew on Do Braces Hurt?
Samantha on Do Braces Hurt?
Samantha on Do Braces Hurt?
Samantha on Do Braces Hurt?
Maddy on Do Braces Hurt?
Marikit on Do Braces Hurt?
sarah on Why Teeth Hurt
Piccoloplayeratrhs on Do Braces Hurt?
Rosemary on Do Braces Hurt?
shannon santiago on Teething Baby Pictures
Fhyzzie Lee on Do Braces Hurt?
Fhyzzie Lee on Do Braces Hurt?
Hadya on Do Braces Hurt?
Hadya on Do Braces Hurt?
Alan on Do Braces Hurt?
blowfish on Do Braces Hurt?
Caitlin on Do Braces Hurt?
bvb lover on Do Braces Hurt?
Vincent on Do Braces Hurt?
dimple on Do Braces Hurt?
Dee dee on Do Braces Hurt?
samantha on Do Braces Hurt?
julie martinelli on How Long Does Teething Last?
Grace Vlahovic on How Long Does Teething Last?
sammie on Do Braces Hurt?
Iris on Do Braces Hurt?
Melody on Do Braces Hurt?
Sadie on Do Braces Hurt?
Maria on Do Braces Hurt?
Sadie on Do Braces Hurt?
Sydd :D on Do Braces Hurt?
laura on Do Braces Hurt?
Stef on Do Braces Hurt?
Stef on Do Braces Hurt?
Harmony on Do Braces Hurt?
Harmony on Do Braces Hurt?
harmony wheeler-11 on Do Braces Hurt?
harmony wheeler-11 on Do Braces Hurt?
Delaney on Do Braces Hurt?
Delaney on Do Braces Hurt?
Dora Wagner-Gluck on Teething Baby Pictures
Beth on Do Braces Hurt?
Delaney on Do Braces Hurt?
christa on Do Braces Hurt?
Hayley on Do Braces Hurt?
beth on Do Braces Hurt?
beth on Do Braces Hurt?
Vanessa on Do Braces Hurt?
Cassidy on Do Braces Hurt?
Corrinne on Do Braces Hurt?
beth on Do Braces Hurt?
Rachael on Do Braces Hurt?
Jonathan Bird on Is Water Fluoridation Legal?
Corrinne on Do Braces Hurt?
Jennifer on Do Braces Hurt?
mjhrusovsky on Why Teeth Hurt
Chels[: on Do Braces Hurt?
Kera on Do Braces Hurt?
Charlene on Do Braces Hurt?
frankieecool on Do Braces Hurt?
banana lover on Do Braces Hurt?
Kera on Do Braces Hurt?
Kera on Do Braces Hurt?
Jennifer Uriarte on What are Tartar and Calculus?
Bony Delicious on Dental School Finals Week