Cavities: most of us have had them, and none of us want them. Whether you want to avoid more or be one of those unicorns who’ve never had a cavity in their lives, prevention is key. And at the core of preventing cavities is knowing what actually causes them.
So, what causes cavities? And how can you prevent them? We’ve got you covered! Below is a primer on how cavities develop, plus how you can avoid and treat them.
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Understanding Cavities: The Basics
Cavities and the tooth decay that cause them are among the most common health problems worldwide. According to the CDC, about 90% of U.S. adults aged 20 and older have had at least one cavity. Many people dismiss them as minor inconveniences, but cavities can cause significant health problems, leading to everything from tooth loss to heart disease.
While they’re most common in older teens and adults, anyone can develop cavities — even infants. Proper oral healthcare can prevent many, but you can’t avoid all cavities with care alone. In the end, genetics and luck play big roles, too.
Types of Cavities
Not all cavities are the same, and dentists classify them based on their location and persistence. Below are the three main types.
- Coronal Cavities: This is the most common type, and they’re defined by their location; they form on the chewing surfaces or between the teeth.
- Root Cavities: Most common in older adults with gum loss or disease, these cavities develop on the tooth roots exposed by gum recession. Tooth roots are vulnerable since they don’t have enamel.
- Recurrent Cavities: Defined by their persistence rather than location, these develop around dental restorations used to treat older cavities. Plaque and tartar adhere to the restorations, making these spots vulnerable.
How Cavities Develop
Not all cavities follow the same path, but most do, and the process starts with plaque formation. This is the sticky substance that forms on your teeth when food particles and saliva mix. That fuzzy texture on your teeth when you haven’t brushed for a while? That’s plaque.
Plaque calcifies and turns into tartar within 24–48 hours. This substance is hard, stuck in place, and you can’t remove it with brushing and flossing alone.
Tartar contains acids and bacteria, which both damage the teeth. The acids weaken and erode the enamel — the protective layer of our teeth — by extracting minerals and opening the pores. The bacteria then attack, creating holes in the teeth, which is the first stage of cavity development.
Mild cavities only impact the enamel, but moderate and severe ones penetrate deeper, into the dentin, and eventually the pulp and root. The deeper a cavity goes, the more invasive treatment will be. That’s why twice-yearly dental appointments are so important; they give you the best chance at catching cavities early, when simple treatments still work.
Top Causes of Cavities
Now you know how cavities form, but that’s not the same as their causes. Many factors come into play, and most people will have multiple causes behind any individual cavity. Below are the most common reasons cavities develop.
Poor Dental Care
The number-one cause of cavities is infrequent or improper brushing and flossing, which lets plaque and tartar flourish on your teeth, creating an ideal environment for cavity formation.
But dental care goes beyond your at-home oral hygiene routine; twice-yearly check-ups and cleanings are also important. Since a dental hygienist will remove tartar at these visits, skipping them increases the likelihood that you’ll end up with cavities.
Misaligned Teeth
Dental misalignments put you at greater risk of developing cavities. Crowded and twisted teeth make proper cleaning more difficult; brushes often can’t get into the nooks and crannies, and many people aren’t skilled enough with dental floss to navigate those awkward spots. This lets tartar develop and eat away at the teeth.
Tooth Shape
Certain teeth naturally have many grooves and pits — like the molars. However, some people have deeper ones than others. This can give plaque better places to hide, allowing it to calcify. That’s why it’s more common to get cavities on your back teeth.
Diet and Hydration
We’ve all heard that sugary foods cause cavities, but it isn’t sugar itself as much as the stickiness of sugary foods. Basically, any foods and drinks that cling to the teeth and are hard to brush away make it easier for plaque to calcify. This includes sugary foods but also dairy products, baked goods, and even pasta. Additionally, acidic foods weaken the enamel, making the teeth more vulnerable.
Another factor to consider is how often you eat and drink. When you steadily consume foods and beverages throughout the day, you don’t give your saliva time to wash things away, making build-up more likely.
A Lack of Fluoride
Fluoride is a naturally occurring mineral that helps keep enamel strong. In fact, if you catch cavities early enough, a professional cleaning and fluoride can reverse them. If you aren’t using fluoridated toothpaste and don’t drink public water, you might not be getting what your teeth need for maximum protection.
Age
Cavities are most common in young children who aren’t adept at brushing and flossing, and older adults. Since the teeth wear down over time and the gums recede with age, older adults are naturally more vulnerable to cavities. Plus, older people often take more medications, some of which cause conditions that make it easier for cavities to develop.
Old or Bad Dental Work
Fillings, crowns, veneers, and more — old or poorly administered dental work makes it easier for bacteria to reach the more vulnerable parts of the teeth and stay there, eating away at the structures. If you have dental restorations, know their average lifespans and get them checked as you near the lower limit.
Poorly Maintained Dental Devices
Also problematic are removable dental devices — like aligners, retainers, dentures, and snap-on veneers — if you don’t properly care for them. You should clean them multiple times a day, or they will be a breeding ground for bacteria and hold it against your teeth, leading to decay.
Certain Medical Conditions
Some medical conditions make you more likely to develop cavities. If you have any of the following medical issues, take extra care with your teeth.
- Dry Mouth: Saliva is your mouth’s first line of defense against tooth decay. When you have chronic dry mouth, there isn’t enough saliva to eliminate food particles throughout the day.
- Heartburn: Since acid reflux brings stomach acid into the throat and mouth, it can wear down the enamel, weakening or even eliminating the protective layer of your teeth.
- Chronic Vomiting: Just like heartburn, this puts stomach acid into direct contact with your teeth. Over time, it can wear down the enamel. Eating disorders, morning sickness, and surgical complications can all cause chronic vomiting.
- Gum Disease: Gum disease goes hand-in-hand with gum recession. This exposes the tooth roots, which lack enamel, leaving them especially vulnerable to cavities.
Preventing Cavities
Now that you know the top causes of cavities, you are better positioned to prevent them. While there is no foolproof method — sometimes, you’re just a victim of genetics — certain habits go a long way toward offering protection.
- See Your Dentist Twice a Year: During these visits, professional cleaning and scaling will eliminate any tartar you have — hopefully before it can cause decay.
- Brush at Least Twice a Day: Use a soft-bristled brush and brush for at least two minutes. Be sure to get all surfaces of the teeth.
- Use Toothpaste With Fluoride: Fluoride helps remineralize and strengthen the enamel, the protective outer layer of your teeth.
- Learn How to Brush Your Unique Teeth: While there are general guidelines on proper brushes, the right approach depends on the shape and position of your teeth.
- Floss at Least Once a Day: Your toothbrush can’t get between your teeth well enough to eliminate plaque there, so flossing is essential.
- Straighten Crooked Teeth: Since misaligned teeth are harder to clean, straightening a crooked smile helps prevent cavities.
- Eat Well: Consume fewer sugary and acidic foods, limit your snacking, and avoid eating after you brush your teeth at night.
- Stay Hydrated: Since saliva washes away food particles, you need to stay hydrated to enhance your first line of defense against cavities.
- Get Dental Sealants: If you have suffered enamel loss or are genetically predisposed to forming cavities, dental sealants can help protect your teeth.
- Keep an Eye on Dental Work: If you’ve had restorations, such as fillings and crowns, watch them for signs of problems and get help if you notice anything wrong.
- Take Care of Dental Devices: If you wear any dental devices, like dentures or a night guard, clean them at least twice a day.
- Mitigate Medication and Illness Side Effects: If your medication or medical condition causes dry mouth or stomach acid to contact the teeth, ask your doctor for help mitigating those side effects.
- Address Dental Injuries Immediately: Any damage to the teeth can give bacteria access to vulnerable tissues. Address these injuries right after they happen.
Treating Cavities
If prevention hasn’t worked out as well as you’d hoped, the good news is that cavities are usually easy to treat. The specifics of this treatment vary based on how severe the cavity is.
As you might expect, early-stage treatment is the least invasive. Typically, this only works when a dentist spots the cavity before you experience any symptoms. This approach cleans the bacteria away and restores the enamel using fluoride.
If your cavity causes symptoms, it’ll probably require some drilling. This approach removes decayed and infected dental tissues, stopping the condition from worsening. Once drilling is complete, your dentist must restore the tooth to protect the remaining tissues from further decay. Fillings are enough for smaller cavities, while larger ones often need crowns. In limited cases, veneers can offer proper protection, but only on the upper front teeth.
If a cavity progresses far enough, it can reach the pulp and root, requiring a root canal. This is often enough to save the tooth, but not always; some cases require an extraction. In this situation, your dentist might suggest an implant or partial dentures to help maintain function and guard against further issues.
Final Thoughts
They say knowledge is power, and now that you know the causes of cavities and steps to prevent them, you can maintain better control over your oral health.
Take good care of your teeth, customize your approach to your needs, and don’t skip your dental visits. And if cavities develop despite your best efforts, know that it’s not necessarily your fault; sometimes, it’s just a matter of genetics or luck.
Frequently Asked Questions
Will everyone get cavities in their life?
No, but most people will. Around 90% of us will experience some form of tooth decay by the time we’re 40. That percentage rises with age, but it never quite reaches 100%.
Are cavities always caused by poor hygiene?
No, you can have excellent hygiene and still end up with cavities from things like medical conditions, bad dental work, or genetics.
What are the earliest signs of cavities?
For most people, the first signs of cavities are sensations — tingling, pain, or sensitivity.
Do cavities always hurt?
No, some people never feel their cavities at all, while others will experience tingling but not pain. However, pain is the most common symptom.
Do cavities always start on the outside of the tooth?
No, sometimes they start within the tooth. That’s part of what makes those six-month check-ups so essential; X-rays are the only way to catch these cavities early.
How are cavities diagnosed?
While your dentist might be able to make a visual diagnosis, you will probably need X-rays, if only to rule out cavities in other teeth.
How can I prevent cavities?
Brush twice a day, floss once a day, eat well, stay hydrated, and get regular dental care. Don’t leave injuries untreated and address health issues that make cavities more likely.
Is it possible to fully prevent cavities?
You might manage it, but there is a certain amount of luck involved. Do your best, but don’t assume you can make the right choices to avoid cavities in all cases.
Is it normal for adults to get cavities?
Yes, it’s completely normal, and most adults will have had at least one by age 40.
Are cavities contagious?
Not the cavities themselves, but you can pass the bacteria that causes them to other people through kissing or sharing food and drinks.
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