What Is a Cavity? Understanding Causes, Symptoms, and Proven Ways to Prevent Cavities

A cavity indicates that your oral care needs attention. If a cavity is left untreated, it can easily escalate from a tiny opening to a toothache, infection, and then tooth loss. Luckily, cavities can be easily prevented by adopting a daily dental hygiene routine. However, to do that, you need to understand how a cavity develops.

In this guide, we’ll discuss what a cavity is, explore its causes and progression, and offer tips to keep your teeth healthy. If you’re managing your baby's teeth or maintaining permanent teeth, here's what you need to know about cavities and how to prevent them.

What Is a Cavity?

A cavity, also known as dental caries, is the decayed area of a tooth that develops into tiny openings or holes. It starts with dental plaque, progresses to tooth decay, and erodes your tooth enamel, which is the hard protective layer covering the inside of your tooth. Cavities are permanent damage that a dentist has to repair with a filling.

Tooth decay occurs when acids produced by bacteria in your mouth attack the enamel. If you're not cleaning your teeth well over time, tiny openings develop where bacteria thrive, leading to tooth decay. You may not notice symptoms right away, but untreated decay can lead to tooth sensitivity, mouth pain, or visible openings. Eventually, the decay reaches the inner tooth material (pulp), causing infection or a tooth abscess.

According to the American Dental Association, cavities and tooth decay are among the most prevalent dental problems in the U.S., affecting both children and adults. Symptoms of cavities include tooth pain, temperature sensitivity, and visible holes or dark spots on teeth. Regular dental checkups can help detect problems early. A trained dental professional uses X-rays and physical exams to identify signs before they become painful.

How Cavities and Tooth Decay Progress

Cavities form over time in the following stages:

Plaque Forms on Teeth: After eating, bacteria in your mouth combine with leftover sugars and starches to form a sticky layer called dental plaque.
Acid Starts the Attack: The plaque produces acid that begins to erode your tooth enamel. This process is called tooth decay. This erosion can start within 20 minutes after you eat or drink.
Enamel Wears Down: As your enamel weakens, the decay penetrates further. Snacking a lot, sipping sugary drinks throughout the day, or vomiting without cleaning your teeth properly exposes your teeth to acid attacks that wear down enamel and raise the risk of cavities.
Dentin Gets Exposed: Under the enamel lies dentin, which is softer and more vulnerable to decay. Once the cavity reaches this layer, it spreads more quickly, causing pain and infection.
Pulp Gets Infected: Deep decay can infect the pulp, causing intense pain, swelling, or a serious toothache. If the cavity reaches this stage, it often leads to a tooth abscess.

Barranca-Enríquez & Romo-González (2022) established in their dental and craniofacial research that tooth decay forms tiny holes that affect both oral health and overall well-being. They emphasize that better oral health means you're able to taste, chew, speak, smile, and show emotion, comfortably and confidently, without pain or disease in your mouth or face.

What Causes Cavities?

A cavity is the inevitable result of the things we do daily. Here are some habits that increase the risk of cavities:

Failing to brush with fluoride toothpaste after eating and before bed.
Skipping flossing or using poor technique.
Snacking and sipping sugary or acidic beverages.
Choosing certain foods and drinks like dried fruits, soda, or sports drinks.
Mouth breathing or smoking (which leads to dry mouth).
Wearing fillings or dental appliances that trap food.
Poor oral care due to age (younger or older).

Even healthy foods, such as fruit juice or dried mango, can cling to your teeth and feed bacteria. Every time you eat or drink sugary foods, you’re feeding bacteria to produce the acid that erodes your enamel.

The 3 Types of Cavities

Understanding the following types of cavities helps you determine the most appropriate treatment options:

Smooth Surface Cavities: Develop on the outer surfaces of teeth, especially between teeth, where flossing is key.
Pit and Fissure Cavities: Form in the grooves of your back teeth, where brushing may miss debris.
Root Cavities: Happen when gums recede, exposing the tooth root, which lacks protective enamel. These are common in older adults.

Dentists use this knowledge to target specific areas of tooth decay and recommend options such as dental sealants, fluoride treatments, or fillings based on the severity.

How to Prevent Cavities: Daily Habits That Work

The easiest way to prevent decay is to stop it before it starts. Here's how you can prevent cavities effectively:

Brush with fluoride toothpaste twice daily. Brushing your teeth well is one of the simplest and most effective ways to prevent cavities. For better results, use Cheeky's Electric Toothbrush, designed for deep cleaning to remove 99% of plaque.
Floss once a day. Flossing is vital for cleaning all tooth surfaces, including hard-to-reach areas, and preventing cavities. For instance, Cheeky's Water Flosser is 50% more effective than string floss for removing trapped debris and plaque.
For more thorough cleaning, consider using Cheeky's LED Whitening Kit for enhanced disinfection.
Eat tooth-healthy foods like crunchy fruits, leafy greens, and dairy to support enamel strength.
Drink water throughout the day, especially after meals.
Chewing sugar-free gum increases saliva production, which neutralizes acids and helps remove debris.
Visit your dentist regularly, at least twice a year, for cleanings and exams. Your dentist can detect cavities early.
Ask your dentist about fluoride treatments and dental sealants if you're at risk of decay. Dental sealants collect food, protecting tooth enamel by covering the chewing surfaces.

These habits will reduce the risk of tooth decay and keep your smile strong for life.

What Happens If You Don’t Prevent Cavities

When prevention slips, intervention steps in. Most cavities get fixed with dental fillings. Here’s how it works:

A dental professional removes decayed material.
They clean and sterilize the area.
They fill it with composite resin or other safe material.

In more severe cases, you may need antiseptic and disinfecting treatments, root canals, crowns, or even extractions.

Untreated cavities can cause:

Toothache infection and tooth loss.
Persistent mouth pain and tooth sensitivity.
High-cost dental procedures.
Damage to permanent teeth and long-term oral issues.

Early detection makes treatment simpler. So if you notice pain when chewing or spots on your teeth, don’t wait, see your dentist to detect the problem early.

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Frequently Asked Questions

Can A Cavity Go Away On Its Own?

No, cavities won’t heal on their own. When mouth bacteria produce acid that erodes enamel, the decay begins and progresses unless a dentist intervenes. Fluoride can certainly remineralize the enamel in the early stages, but it won’t repair microscopic cracks and cavities that have already begun. If you leave them untreated, the cavities will excavate further into the tooth, increasing the possibility of an abscess, infection, and even tooth loss. The American Dental Association recommends treating the decay early to prevent tooth loss.

What are The Early Signs of a Cavity?

Catch decay early, and you can often avoid more invasive treatment. Early signs include:

Sensitivity of the teeth to hot, cold, and sweet substances.
Visible white spots or darkened areas on the surface of your tooth.
Discomfort when chewing or brushing.

If you find yourself snacking frequently, sipping soda, juices, or sticky snacks like milk, ice cream, honey, sugar, or dried fruits, you're feeding the bacteria that cause decay. These habits raise mouth acid levels, creating a perfect environment for cavities to form.

How Fast Do Cavities Spread?

Cavity progression varies depending on your daily routine. If you’re sipping a lot of sugary drinks or mouth snacking a lot, you're prolonging acid attacks on enamel. Cavities spread faster when your teeth stay under that kind of constant pressure. Poorly fitted fillings or dental devices trap even more food and plaque in hard-to-reach areas. That’s why the Centers for Disease Control stress the importance of prevention through brushing, flossing, and regular cleanings.

What Happens If a Cavity Goes Untreated?

If you ignore a cavity, it’ll dig in. The decay spreads from the enamel into the dentin and eventually reaches the nerve-rich pulp, causing pain, swelling, and, in some cases, a tooth abscess. You could end up needing a root canal or losing the tooth entirely. The Centers for Disease Control and Prevention and Mayo Clinic Press both highlight the link between untreated cavities and long-term oral health issues.

What Does Cavity Pain Feel Like?

Cavity pain can vary, but usually includes:

Sharp or throbbing pain when chewing.
Sensitivity that lingers after consuming hot or cold foods and drinks.
A dull ache that doesn’t go away.

In kids, bedtime baby feeding can expose teeth to prolonged sugar and trigger early decay, also called baby bottle tooth decay. In adults, habits such as repeated vomiting called purging washes, or conditions like gastroesophageal reflux disease (GERD), can wear down enamel and expose teeth to acid, even if you’re brushing regularly.

And it’s not just sweets. Highly processed cream, honey, sugar, soda, and even milk ice cream leave behind residue that bacteria feed on. Once that cycle starts, pain is a clear sign you need professional treatment fast.

Final Thoughts: Healthy Teeth, Healthy Life

Teeth can get cavities if you neglect them, but they’ll also thrive if you give them a little love every day. By understanding what a cavity is, you’re already on the path to better oral health. Use the right tools, stick to a simple routine, and trust that prevention always beats treatment.

If you’re managing baby bottle tooth decay, protecting your back teeth, or simply trying to avoid the next tooth abscess, we’ve got your back. Your smile deserves the best. And with Cheeky, you don’t have to wait for your next appointment to get it.

References

American Dental Association. (n.d.). Nutrition and oral health. American Dental Association.
Barranca-Enríquez, A., & Romo-González, T. (2022). Your health is in your mouth: A comprehensive view to promote general wellness. Frontiers in Oral Health, 3, 971223.
Mayo Clinic. (2023, June 1). Cavities (tooth decay): Symptoms and causes.
The Centers for Disease Control and Prevention (CDC). (2024, May 15). Oral Health: About cavities (Tooth decay).