What Are the Causes of Tooth Decay?

Knowing the symptoms and causes of tooth decay can help you manage your oral health. Learn about the signs of cavities and how to prevent them here.

While 13.2% of children have untreated dental caries, about 26% of adults (ages 20 to 44) have cavities as well. Understanding the common causes of tooth decay can help you avoid dental cavities before they develop. Otherwise, you might start experiencing painful symptoms.

Tooth decay can put your overall health at risk if bacteria get the chance to spread. 

What are the causes of cavities exactly, and when should you visit your family dentist for treatment? Read on to find out!

What is Tooth Decay?

Before we discuss the causes of tooth decay, let's cover the basics. 

Cavities, also called tooth decay or dental caries, are damaged areas in the hard surfaces of your teeth. In time, they can cause tiny openings or holes to develop. Untreated dental caries in permanent teeth is now the most common health condition worldwide

About two million people suffer from caries of permanent teeth. Another 514 million children suffer from caries of their primary teeth. 

Anyone who has teeth can experience tooth decay; even infants.

When left untreated, the cavities can grow larger, eventually affecting deeper layers of the tooth. 


Tooth decay is a process that occurs over time. Here are a few common causes and risk factors that could lead to dental cavities. 

Plaque Formation

When food particles and the bacteria in your mouth mix together, plaque can develop. Plaque is the clear, sticky film that can coat your teeth. It develops when starches and sugars aren't cleaned away from your mouth.

Otherwise, bacteria can start feeding on these sugars and starches, prompting plaque to form.

If you neglect to brush and floss your teeth after meals, plaque can linger on your teeth. In time, it can harden under or above your gum line, turning into tartar (calculus). It's difficult to remove tartar with only a toothbrush.

Routine dental appointments will allow your dental hygienist to remove plaque before it hardens into tartar. If tartar has developed, they can use specialized tools to remove it from your teeth.

The acids in plaque can remove minerals from your tooth's protective outer enamel. Tiny holes can form; the first stage of cavity development. 

After wearing away your protective tooth enamel, the acid will reach the next layer: the dentin. Dentin is softer than enamel and therefore less resistant to acid. 

Dentin is structured with tiny tubes, which communicate with tooth nerves. When the dentin is damaged, sensitivity can occur.

The bacteria and acid will continue destroying your teeth. They'll move to the pulp; the inner tooth material that contacts nerves and blood vessels. The pulp will become irritated and swollen, causing pain and discomfort. 

Lack of Flouride

Fluoride helps prevent cavities from forming. It can even erase tooth damage at the earliest stages. 

A lack of fluoride could leave your teeth vulnerable to tooth decay. 


Young children and older adults are at higher risk of tooth decay.

As you get older, wear and tear can occur. Your gums can recede from your teeth, making them more vulnerable to decay. 

Some medications can reduce saliva flow, increasing your risk of tooth decay further. 

Dry Mouth

Saliva washes food particles and plaque away from your teeth. Saliva also contains substances that counter the acid that can cause decay. If your mouth is dry often, it could increase your risk of dental cavities. 

Some medications can reduce saliva production.

Eating Disorders

An eating disorder like bulimia or anorexia can cause tooth erosion, increasing your risk of cavities. Vomiting allows stomach acid to wash over your teeth. Protective tooth enamel could get damaged, leaving your teeth vulnerable. 


Gastroesophageal reflux disease (GERD) and heartburn cause stomach acids to flow into the mouth (acid reflux). This acid can damage your protective tooth enamel, leaving you vulnerable to decay.

Talk to your dentist if reflux is a common problem.


The symptoms of tooth decay you experience can vary based on where the tooth is located or how long the cavity has had time to develop. When a cavity is beginning to form, it's normal not to notice any symptoms. In time, however, the decay can spread, allowing holes in your teeth to get larger.

As a result, common symptoms of tooth decay include:

If you experience these symptoms, visit your local dentist right away. 

When to See a Dentist

Remember, you may not realize a cavity is forming while it's still in the initial stages of development. As a result, it's important to schedule routine visits with your dentist. Routine appointments will allow your dentists to spot potential issues with your dental hygiene.

They can help by offering preventative tips, too.

If you experience any toothaches or mouth pain, make sure to visit your dentist right away. Otherwise, schedule a check-up every six months. 

The Causes of Tooth Decay: Visit Your Dentist Today

Remember, neglecting to check in with your family dentist could put your dental care at risk. Instead, visit every six months. They can spot signs and causes of tooth decay at the initial stages.

With routine appointments, you can treat and prevent decay before dental cavities form.

Ready to schedule your next appointment? We can't wait to see you.

Schedule your first visit today to get started.