5 Common Causes of Cavities and the Best Ways to Prevent Them

Cavities are one of the most common dental challenges faced by both children and adults. There are several reasons that cavities develop in teeth. A substance called “plaque” is to blame. This sticky film is full of bacteria and likes to accumulate in small spaces in and around the teeth. When plaque isn’t removed by regular brushing and flossing, it thickens and forms into tartar, which is hard to remove — and increases your risk of cavities.

Understanding what causes cavities to form can help you to better prevent them. Let’s take a closer look at five common causes of cavities and steps that you can take to keep your smile healthy and cavity-free.  

1. An unbalanced diet

Remember that what you eat matters. Eating and drinking foods that are high in sugar will cause an acidic environment to form inside of your mouth. If not cleaned properly, your tooth structure will weaken, and a cavity may form.

Foods and eating habits that may increase your risk for developing a cavity include:

• Sweetened drinks like sodas and sports drinks

• Foods that have added sugar

• Hard candies, or other sweetened snacks that you suck or chew for a while

• Sipping a sweet drink over time, rather than drinking it quickly

2. Improper brushing and flossing

If you’re unable to clean your teeth properly, this will leave them vulnerable and covered by plaque. Having a buildup of plaque is one of the fastest ways to have cavities form in your teeth. Brush your teeth at least twice a day for 2 minutes and floss at least once a day. Using mouthwash without alcohol can also help.

Having the best technique for brushing and flossing can help you keep your teeth clean. For some, this may mean opting for an electric toothbrush over a manual toothbrush. For those at high risk of plaque buildup or gum disease, an electric toothbrush may be a better choice. Likewise, if you find flossing difficult, a water flosser may be easier to use. 

3. Gum recession

Over time, repeated gum trauma or gum disease can cause your gums to recede or pull away from the teeth. This exposes a part of your tooth that’s normally covered and protected by your gums. The resulting exposed tooth structure, which may include the root, is more susceptible to tooth decay.

In severe cases, gum recession can be treated with gum graft surgery. This can help to protect the teeth and prevent more tooth decay.

4. Dry mouth

Saliva helps to sweep away the plaque on your teeth, keeping the acids and bacteria that cause cavities at bay. If you have a lack of saliva, it prevents this cleaning mechanism and can make a cavity more likely to form.

A change in your daily medications may lead to a decrease in saliva and subsequent dry mouth. In this case, speak with your prescribing healthcare provider about possibly changing the dosage or brand of this new medication.

Common medications that can lead to dry mouth include:

• Selective serotonin reuptake inhibitors, like fluoxetine

• Medications to treat high blood pressure, such as propranolol

• Medications to treat Parkinson’s disease, like benztropine

• Antihistamines, like diphenhydramine

• Decongestants, such as pseudoephedrine

• Prescription pain medications, like hydrocodone/acetaminophen (Norco)

• Muscle relaxants, like cyclobenzaprine

5. Teeth grinding

Grinding your teeth against each other can reduce the thickness of the protective enamel layer around your teeth. This leaves your teeth more susceptible to cavity formation.

Some people grind their teeth while awake in response to stress or anger. But most tooth grinding happens unknowingly while sleeping. Signs that you may grind your teeth include:

• Chipped or cracked teeth that you can’t otherwise explain

• Popping or clicking of the jaw or temporomandibular joint (TMJ)

• Jaw pain

• Headaches

• Damage to the inside of the cheeks

If you grind your teeth, your dentist may suggest that you wear a night guard around your teeth while you sleep. This is a plastic device that can be fitted to cover your teeth and protect them at night, decreasing your risk of damage.

How do you prevent cavities?

The best way to prevent cavities is to adopt a healthy oral hygiene routine. Your dental care routine should include the following:

• Schedule a routine dental cleaning and exam at least every 6 months. Staying on a regular cleaning schedule will allow the proper removal of tartar buildup. This will reduce your chances of a cavity forming. Also, your dentist will be able to proactively treat small cavities before they have time to grow deeper and larger.

• Rinse your mouth with nonalcoholic mouthwash after brushing and flossing. This will help reduce even more bad bacteria from sticking around your teeth. Alcohol in mouthwash can dry your mouth, reducing the saliva that helps to remove plaque.

• Brush your teeth twice a day with fluoride toothpaste. Having fluoride in your toothpaste will help strengthen your tooth structure.

• Avoid frequent snacking and sipping of sugary drinks throughout the day. Frequent snacking between your regular brushing times will thicken the plaque biofilm and allow the bacteria in your mouth to thrive.

Can a cavity go away?

A cavity can go away on its own, but very rarely. A cavity can only be reversed when it’s in the very beginning stage called demineralization. This is when the tooth structure begins to be weakened by acid from tartar and plaque. These early cavities may look like white spots on the teeth. 

A dedicated and healthy oral hygiene routine can help to replenish your teeth of lost minerals to keep the cavity from worsening. Unfortunately, most people don’t catch cavities this early as they’re hard to see. When cavities are past the initial demineralization stage, they need to be addressed by a dentist and treated accordingly.

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Written by:

Zack Youngblood, DMD

Zack Youngblood, DMD, is a dentist who strives to change the general look of dentistry. Before stepping foot in the clinical field, he authored multiple works that helped dental students and dentists find their unique path in dentistry.

Edited by:

Karla Robinson, MD

Karla Robinson, MD, is a medical editor for GoodRx. She is a licensed, board-certified family physician with almost 20 years of experience in health through varied clinical, administrative, and educational roles.

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