What Causes Cavities?

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What Causes Cavities?

We’ve all had to deal with a dreaded dental cavity or two. Cavities develop when bacteria present in our mouths use carbohydrates to produce acid which erodes tooth enamel. Infection by oral pathogens, poor oral hygiene, bottle feeding, frequent snacking, smoking, excessive alcohol consumption, and sugary, crunchy, or sticky foods can up your risk for cavities. You also have a higher risk if you have dry mouth or bulimia.

Most of us have had to deal with a dental cavity at some point or the other. In fact, the World Health Organization estimates that around 60 to 90% of school children and almost all adults have cavities.1 Cavities are more likely to develop on the surfaces that you use to bite and the areas between your teeth where food particles tend to lodge.2 Tooth decay may also occur in crevices around fillings where the filling has fractured or weakened3

Now, we all know that cavities can cause serious problems like pain, tooth loss, tooth abscess, serious infection, and trouble chewing.4 But have you ever wondered how cavities really develop? Read on to find out!

What Causes Cavities?

Your mouth contains bacteria which are harmful to your teeth and these tend to form a film known as plaque over your teeth. You may be able to feel this sticky substance if you run your tongue over your teeth before you brush. The tooth surfaces that feel slightly rough and furry rather than smooth are likely to have plaque on them. The bacteria in plaque convert carbohydrates from the food or drinks that you consume into energy for its needs and, in the process, also produces acid. This acid can eat away at the enamel of your teeth in a process known as demineralization.

But your teeth are not completely defenseless against this acid attack. Minerals like phosphate and calcium present in saliva and fluoride from water or toothpaste can help replace lost minerals and repair your enamel in a process known as remineralization. Tooth enamel typically gets demineralized and remineralized many times during the day, but some factors can upset this balance. As a result, the rate at which minerals are lost exceeds the rate at which they are replaced. When this happens, over time, the surface of the enamel starts to break down and a hole or cavity begins to develop.

As the decay progresses, bacteria first breach the enamel and enter the softer layer known as dentin which lies beneath. They then progress to the pulp which contains blood vessels and nerves. At this point, you typically experience pain. Bacteria can also cause an abscess in the pulp and even spread to your bone.5

What Can Increase Your Risk For Cavities?

Let’s take a look at some factors that can up your risk for cavities.

Infection By Oral Pathogens

Adults typically have bacteria that cause tooth decay in their mouths. But according to research, babies are not born with these bacteria. So how do these oral pathogens infect your baby? They’re usually passed on through the saliva of a caregiver, mostly the mother. And this can happen quite early in life before your baby even has her first tooth.

Now, people with cavities have increased levels of cavity-causing bacteria in their mouth and are, therefore, more likely to pass it on. So, getting proper treatment for cavities as well as avoiding sharing things like forks or spoons with your baby can lower the risk of transmission.6

Poor Oral Hygiene

As we saw, plaque contains bacteria which release tooth-decaying acid. The lack of an appropriate routine for maintaining oral hygiene can lead to the development of cavities. Brushing twice a day with a fluoride toothpaste and flossing every day can help clear out plaque and keep your teeth clean. Oil pulling with sesame or coconut oil every day can also improve your oral health. Here are effective tips to heal cavities naturally.

Frequent Snacking

Snacking frequently on foods with carbs like sweets, juice drinks etc. increases the number of times your teeth come in contact with foods that can be used by bacteria to produce enamel-destroying acids. This means an increase in the frequency of acid attacks on your teeth and a greater chance of tooth decay.7

Sticky, Crunchy, And Sweet Foods

The bacteria in your mouth love sugar. So sweets or other foods high in sugar can be especially bad for your teeth. Sticky foods like dates or toffee which tend to cling to your teeth or crunchy foods like chips which can get lodged in between teeth also increase your chances of developing cavities as they remain in contact with your teeth for longer periods.8 Children especially tend to gather cavities through this route.

Dry Mouth

Dry mouth is a condition characterized by low levels of saliva in the mouth. Saliva is your natural defense against demineralization. Not only does it neutralize and dilute acids which erode your enamel, but it also contains minerals which are used to remineralize your teeth. So low levels of saliva can increase your chances of getting cavities. Medical conditions like Sjögren’s syndrome, diabetes, disorders of the salivary glands, nerve damage, chemotherapy, as well as certain medicines can cause dry mouth.9

Smoking And Alcohol Consumption

The use of tobacco can impede the production of saliva while excessive consumption of alcohol can play a part in the erosion of enamel. So avoid smoking and keep your alcohol intake moderate to keep your teeth healthy.10


Bulimia is an eating disorder characterized by episodes of binging on food and then purging by vomiting or using of laxatives or enemas. Vomit is acidic in nature and excessive exposure to it can wear away the enamel of your teeth.11 This can lead to poor oral health and up your risk of cavities.

Bottle Feeding With Sugary Drinks

Bottle feeding with sugary drinks can keep your baby’s or toddler’s teeth in contact with sugar for long periods of time. And as we already saw, bacteria use these carbohydrates to produce acid which can cause cavities. Putting your baby to bed with a bottle containing something high in sugar like fruit juices, milk, or formula is a particularly bad idea. In case your baby needs a bottle to go to sleep, give her plain water. Also, do keep in mind that the American Dental Association recommends that children should be persuaded to start using a cup by the age of one.12 This can help reduce the risk of cavities for your toddler.

References   [ + ]

1. Oral health. World Health Organisation.
2. Dental Decay. Oral Health Foundation.
3. Decay. American Dental Association.
4, 5, 9. Dental Caries (Tooth Decay). Dental Health Foundation.
6. Early Childhood Caries. California Dental Association.
7. Snacking and Cavities. Program For Early Parent Support.
8. Top 9 Foods That Damage Your Teeth. American Dental Association.
10. Tooth decay. National Health Service.
11. Bulimia. National Institutes of Health.
12. Statement on Early Childhood Caries. American Dental Association.