Cavities 101: A Guide to What Causes Cavities and More

Photo: chormail via 123RF

Routine visits to the dentist are an essential part of good dental health. During a cleaning or exam, or when reading your X-rays, your dentist might discover a cavity on one or more surfaces of your teeth. But what causes cavities? How common are they? What are some cavity symptoms? What food causes cavities, and how are they treated?

At Sanitas Family Dentistry, we believe that knowledge is key to empowering our patients. Let’s explore the answers to these questions to raise your awareness of cavities and promote good dental habits.

What Exactly Is a Cavity?

When you eat and drink, bacteria, plaque, and acids that mix in your mouth can cause tooth decay that damages the hard, protective outer layer of your teeth (called enamel). When left untreated, tooth decay can form holes in your teeth called cavities (also known as dental caries).

How Common Are Cavities?

Cavities are a common health concern for people of all ages in the United States. The CDC’s 2024 Oral Health Surveillance Report showed:

• More than one in 10 children aged two to five had at least one untreated cavity in their baby teeth.

• Half of all children aged six to nine years have had cavities in their primary or permanent teeth.

• One in 10 adolescents aged 12 to 19 had at least one untreated cavity in their permanent teeth.

• One in five adults aged 20 to 64 years had at least one untreated cavity.

Where Do Cavities Form on Your Teeth?

Cavities can form on multiple surfaces of your teeth, including:

• On the crown (the part that extends from your gums and you see when you look in the mirror) or between your teeth

• On the top part of your tooth’s chewing surface or the front side of your back teeth

• At the root of your tooth

What Causes Cavities?

Ultimately, tooth decay is what causes cavities. So, to understand what actually causes cavities, you need to know how tooth decay progresses.

Tooth Decay Progression

In the early stages, tooth decay breaks down the minerals in your tooth enamel, and white spots may appear. Left untreated, the decay continues to break down the enamel, and holes (cavities) may become visible. You may see light brown spots on your teeth.

In the next phase, decay reaches the dentin (which is a soft layer underneath the tooth enamel). When the plaque and bacteria hit this layer, cavities form more quickly. You might also notice teeth sensitivity or dark brown spots on your teeth in this stage.

If tooth decay reaches the pulp (the innermost layer of your tooth), you may feel pain or notice swelling and redness around your gums surrounding the affected tooth. Any visible spots may also become darker brown or black.

Signs of a Tooth Abscess

An untreated deep cavity can cause an infection called an abscess. When this occurs, a pocket of pus forms around the tooth root and can be very painful. Symptoms of an abscess include:

• Jaw or facial pain

• Facial swelling

• Swollen lymph nodes in your neck

In some cases, you may wonder what cavities cause in your body. Unfortunately, a tooth abscess can spread to surrounding tissues or other places.

Rare, serious complications can cause the infection to spread to your brain or bloodstream – which can cause sepsis. To help reduce the risk of complications, it’s critical not to leave any dental concerns or pain untreated — and to seek professional dental help as soon as possible.

What Is Plaque and How Does it Form?

Plaque is a sticky substance that coats your teeth and destroys your tooth enamel. It forms when bacteria, saliva, acid, and food mix while eating. Acids in dental plaque break down enamel, creating holes — or cavities — in the enamel surface.

Proper brushing and flossing after meals can help remove and prevent plaque buildup.

What Causes Cavities in Kids?

Simply put, tooth decay causes cavities in kids. The following factors may raise the risk of a child getting tooth decay:

• Poor oral hygiene

• Water with limited or no fluoride

• High amounts of oral bacteria that cause cavities

• A sugar and starch-heavy diet

• Reduced saliva flow

What Causes Cavities in Adults?

All the tooth decay risk factors mentioned above that cause cavities in kids also apply to adults. Let’s review them and add some additional cavity risk factors for adults.

• Failing to brush and floss teeth regularly (at least twice a day for two minutes) and after meals

• Consuming a high-sugar, high-starch, or highly acidic diet

• Deep teeth crevices that catch food and allow more room for plaque to form

• Excessive dry mouth/reduced saliva flow

• Grinding your teeth in your sleep or throughout the day, which wears down enamel

• Genetics causing a family history of dental issues/tooth decay

• Life changes that negatively affect oral hygiene or dietary habits, including stress, moving to a new home, starting a new job, or starting school

• Receding gums, which expose more of your teeth and make them vulnerable to decay

• Brushing teeth too hard

• Spacing dental appointments too far apart or not going to the dentist at all (going every six months for a teeth cleaning and exam is best)

What Food Causes Cavities?

The foods and beverages that people of all ages consume have a significant impact on dental health.

The American Dental Association warns that sugar-laden drinks like soda, lemonade, juice, and sweetened coffee or tea “are particularly harmful because sipping them causes a constant sugar bath over teeth, which promotes tooth decay.”

Photo: theoracle007 via 123RF

Hard and sticky candy like lollipops, caramel, mints, and taffy, sweets like cake, muffins, pie, and cookies, and starchy snacks like potato chips, crackers, and pretzels contain empty calories that offer no nutritional value. Plus, the amount and type of sugar they contain that adheres to teeth also helps form tooth decay.

You should also be cautious when eating nutritious, acidic foods like tomatoes and citrus fruits, as they can erode enamel. So, the ADA advises eating them with a meal, not by themselves. Even dried fruit, like raisins, stick to your teeth and produce plaque acids that harm your teeth.

What Foods Are Good for Dental Health?

The extensive list of foods to avoid may sound worrisome; however, thankfully, there are plenty of foods that are good for your dental health.

For example, calcium-rich foods and beverages like milk, cheese, plain yogurt, calcium-fortified tofu and nutrient dense leafy greens and almonds can promote tooth health.

Foods high in protein, such as meat, poultry, fish, milk, and eggs, are excellent sources of phosphorus. Both minerals — calcium and phosphorus — are vital for dental health as they help protect and rebuild tooth enamel.

Fruits and vegetables are not only part of an overall healthy diet but also offer fantastic benefits for your teeth. They are high in water and fiber, meaning they balance their natural sugars and clean your teeth.

Plus, they stimulate saliva production, which helps wash food and acid away from your teeth while also neutralizing the acid in your mouth to guard against tooth decay. Also, Vitamin C-rich foods promote healthy gums, and foods containing Vitamin A help build tooth enamel.

The best beverage of choice to support a healthy smile is fluoridated water.

What Are Daily Sugar Limits and Common Sources of Added Sugar?

Limiting your daily sugar intake as much as possible is best for your health — and for your teeth. Natural sugars, like those in fruit and milk, are part of a daily total sugar intake. Currently, the FDA does not have a daily total sugar intake recommendation.

Added sugars refer to sugars introduced during food processing (like sucrose and dextrose), those found in packaged sweeteners (such as table sugar), and sugars concentrated in fruit or vegetable juices.

The Daily Value for added sugar is 50 grams per day, based on a 2,000-calorie daily diet. Also, the Dietary Guidelines for Americans recommends limiting added sugar intake to less than 10% of total daily calories, and children under two years old should not have any added sugar at all.

When choosing what to eat and drink, you should limit your intake of common sources of added sugar. Some sources are ingredients on a food item’s nutrition label. They include:

• Regular soda

• Sweetened coffee and tea

• Fruit drinks that are NOT 100% juice

• Energy drinks

• Flavored milk

• Cookies, cake, and candy

• Ice cream

• Donuts

• Granola bars

• Flavored yogurt

• Many breakfast cereals

• Brown sugar, sugar, confectioners’ or powdered sugar

• Glucose

• Fructose

• High fructose corn syrup

• Corn syrup

• Corn sweeteners

This list is not all-inclusive. When you read food labels, anything ending in “ose” is a sugar ingredient, and the lists are weighted. So, if you see any of these ingredients high on the list, the item is high in sugar.

Tips for Cutting Back on Added Sugar Intake

Cutting back on added sugars is a vital part of maintaining good dental health and helping to prevent cavities. These healthy swaps can make a positive difference:

• Replace soda with water, sparkling water, or unsweetened tea.

• Eat plain oatmeal or plain yogurt with fruit instead of sugary breakfast cereal.

• Trade your candy dish for a fresh fruit bowl.

• Drink plain coffee or use a low or no-calorie sweetener instead of sugar.

• Reduce dessert portion sizes or share a dessert with someone else.

More Cavity Prevention and Oral Health Tips

Reducing sugar and added sugar intake is a vital step in preventing cavities for people of all ages. Other preventive and good oral health measures include:

• Drink fluoridated water.

• Brush your teeth for at least 2 minutes, twice a day, with fluoride toothpaste.

• Floss daily to dislodge food particles from between your teeth that can cause plaque.

• Don’t smoke or use tobacco products.

• Reduce alcohol intake.

• Visit your dentist for a dental cleaning and exam at least once a year, preferably every six months, to spot and resolve any dental issues, including oral cancer, oral health issues, and cavities.

Common Cavity Symptoms

If you do develop a cavity, you might not have any symptoms at all in the early stages. As the decay spreads to deeper layers of your teeth, you may experience:

• A toothache

• Mouth pain

• Bad breath

• Bleeding gums

• Facial swelling

• Pain when you bite down

• Tooth sensitivity upon contact or touch

• Pain when you eat or drink sweet, hot, or cold items

• Visible black or brown stains on your teeth

• Visible holes or pits in your tooth

What to Do if You Have a Cavity and How Cavities are Treated

If you suspect you have a cavity or are experiencing pain, swelling, or other symptoms, contact us as soon as possible to schedule an appointment to address and diagnose your issues.

Cavity treatment will depend on the severity of decay and may include fluoride treatments, fillings, or tooth extraction.

At Sanitas Family Dentistry, we treat the person, not just the teeth. We treat patients of all ages and offer personalized care in every case. We are here to listen to you with kindness and compassion and resolve your dental concerns to help you restore your smile.

Call us today at (303) 449-8875 to schedule a consultation in our Boulder office.