What is a cavity?
A cavity is a hole in a tooth that develops from tooth decay. Cavities form when acids in the mouth wear down, or erode, a tooth’s hard outer layer (enamel). Anyone can get a cavity. Proper brushing, flossing and dental cleanings can prevent cavities (sometimes called dental caries).
How common are cavities?
More than 80% of Americans have at least one cavity by the time they enter their mid-30s. Cavities are one of the most common chronic diseases that affect all ages.
Who might get a cavity?
Tooth decay can happen at any age, although cavities are more common in children. They may not brush properly and consume more sugary foods and drinks.
Adults also get cavities. Sometimes, new decay develops around the edges of cavities treated in childhood. Adults also are more likely to have receding gums. This condition exposes the lower parts of teeth to cavity-causing plaque.
What are the types of cavities?
Tooth decay can affect all layers of a tooth. It can take three years for a cavity to form in the strong outer layer of tooth enamel. Decay progresses more quickly through the dentin (middle layer) to pulp (innermost layer). Pulp contains a tooth’s nerve endings and blood supply. Types of tooth decay include:
- Smooth surface: This slow-growing cavity dissolves tooth enamel. You can prevent it — and sometimes reverse it — with proper brushing, flossing and dental cleanings. People in their 20s often develop this form of tooth decay between their teeth.
- Pit and fissure decay: Cavities form on the top part of the tooth’s chewing surface. Decay also can affect the front side of back teeth. Pit and fissure decay tends to start during the teenage years and progresses quickly.
- Root decay: Older adults who have receding gums are more prone to root decay. Gum recession exposes the tooth’s root to plaque and acid. Root decay is difficult to prevent and treat.
Symptoms and Causes
What causes cavities?
Many factors play a role in the development of cavities. These steps typically occur:
- Bacteria in the mouth feed on sugary, starchy foods and drinks (fruit, candy, bread, cereal, sodas, juice and milk). The bacteria convert these carbohydrates into acids.
- Bacteria, acid, food and saliva mix to form plaque. This sticky substance coats the teeth.
- Without proper brushing and flossing, acids in plaque dissolve tooth enamel, creating cavities, or holes.
What are the risk factors for cavities?
Certain factors increase your risk of cavities:
- Conditions like Sjogren’s syndrome, or medications like antidepressants, that cause dry mouth.
- Consuming sugary, starchy foods or drinks and snacking between meals.
- Family history of cavities.
- Previous radiation therapy to treat head and neck cancer.
- Receding gums.
What are the signs of cavities?
Tooth decay on the outer enamel surface doesn’t usually cause pain or symptoms. You’re more likely to experience symptoms as decay progresses into the dentin and root. Signs of cavities include:
Diagnosis and Tests
How are cavities diagnosed?
Twice-a-year dental checkups are the best way to catch cavities early when your dentist can save much of the tooth. Your dentist will use various instruments to examine your teeth. A tooth with a cavity will feel softer when your dentist probes it. You may also get dental X-rays. X-rays show cavities before the decay is visible.
Management and Treatment
How are cavities managed or treated?
Treatment depends on the severity of tooth decay. Cavity treatments include:
- Fluoride: When decay is caught early, fluoride treatments can repair tooth enamel. This process is called remineralization. You may need prescription toothpaste and mouthwash, as well as fluoride treatments at the dental office.
- Fillings: Once a hole forms in the tooth, dentists drill out the decayed material and fill the hole. Dental fillings are made of silver amalgam, composite resin or gold.
- Root canal: A root canal treats pain from root decay. Endodontists are dental specialists who treat problems that affect a tooth’s root. During a root canal, this healthcare provider removes the pulp that contains nerve endings that cause pain.
- Tooth extraction: If a root canal isn’t possible, your healthcare provider may extract (pull) the tooth. You may need a dental implant to replace a pulled permanent tooth. Implants keep teeth from shifting and changing your appearance and bite.
How can I prevent a cavity?
- Tooth-brushing with a fluoride toothpaste at least twice a day, and preferably after every meal.
- Cutting back on sugary, starchy foods and drinks.
- Daily flossing to get rid of food and plaque stuck between teeth.
- Dental checkups at least twice a year.
- Dental sealants to protect the top chewing surfaces of teeth.
Outlook / Prognosis
What are the complications of cavities?
When tooth decay goes untreated for too long, you can lose a large portion of the tooth and need an extraction. Advanced tooth decay can lead to a severe infection inside the tooth and under the gums (tooth abscess). This infection can spread throughout the body. Rarely, infection from a tooth abscess can be fatal.
What is the prognosis (outlook) for people with cavities?
Most people with cavities don’t experience any long-term problems. Because cavities develop slowly, it’s important to get regular dental checkups. Fluoride treatments can stop tooth decay in its early stages. Once tooth decay advances to the root, you risk losing the tooth or developing a painful abscess (infection).
When should I call the doctor?
You should call your healthcare provider if you experience:
- Bleeding gums.
- Difficulty chewing.
- Signs of infection.
- Swollen face.
- Toothache or mouth pain.
What questions should I ask my doctor?
You may want to ask your healthcare provider:
- Why did I get a cavity?
- What is the best treatment for this cavity?
- What steps can I take to lower the risk of getting more cavities?
- Should I look out for signs of complications?
A note from Cleveland Clinic
Regular dental checkups and good oral hygiene are key to preventing cavities. Newer dental treatments, including dental sealants and fluoride rinses, have lowered cavity risk in children and teens. Adults who have dental fillings from their childhood may develop cavities around the edges of the old fillings. Older adults may also develop cavities in roots that are exposed from receding gums. Ask your dentist about steps you can take to protect your oral health and prevent cavities.