Cavities (Tooth Decay)

A cavity is a hole in your tooth caused by tooth decay. Cavities form when acids in your mouth damage your tooth enamel, the hard outer layer of your tooth. Anyone can get cavities. Proper oral hygiene and regular dental cleanings can prevent them. Dental caries is another name for cavities.

Types of cavities

Cavities can start on any tooth surface:

• Smooth surface cavity: This type slowly dissolves tooth enamel. People in their 20s often develop this form of tooth decay between their teeth. Good oral hygiene can prevent a cavity.
• Pit and fissure cavity: This is a cavity on the top part of your tooth’s chewing surface. Decay can also affect the front part of your back teeth. This type tends to affect teenagers. Without treatment, it can get worse very quickly.
• Root cavity: This often happens with receding gums. With this issue, your gums pull away from your teeth, exposing your tooth roots to dental plaque and acid. Root decay is difficult to prevent or treat.

Cavity symptoms

Cavity symptoms may not start until decay moves through the enamel and into deeper layers of your tooth. Symptoms may include:

• Bad breath or a bad taste in your mouth
• Bleeding gums or other signs of gum disease
• Facial swelling
• Toothache or mouth pain
• Tooth sensitivity

A tooth has five layers. Over time, tooth decay can affect all layers. Your dentist may refer to these tooth decay stages:

• Demineralization: Small, white, chalky spots form on your tooth. This happens as minerals in your enamel break down.
• Enamel decay: White spots on your teeth may turn light brown, and you can see holes in your tooth. With this stage, decay breaks down more enamel.
• Dentin decay: Light brown spots become dark brown ones. Your tooth is sensitive to hot and cold. Dentin is softer than enamel, so cavities tend to form more quickly once they reach this part of your tooth.
• Pulp damage: Brown spots on your tooth get darker or turn black. Your tooth starts to hurt when cavities reach the tooth pulp. The gums around your tooth may swell or look red.
• Abscessed tooth: Your face and jaw may hurt if a deep cavity causes an infection. Your face and lymph nodes in your neck may swell. You can’t see it, but there’s a pocket of pus at the tip of your tooth root. The abscess the cavity causes can spread to other parts of your body.

Cavity causes

Cavities form when bacteria in your mouth make acid that eats through your tooth enamel:

• When you eat, bacteria in your mouth mix with food to form dental plaque.
• Plaque contains bacteria that turn sugar and starch from the foods you eat into acid.
• Acid breaks down your tooth enamel to make a cavity.

Risk factors

Several issues increase your risk, including:

• Age (cavities are more common in children)
• Dry mouth
• Family history of tooth decay
• Meals and snacks made of sugary and starchy foods
• Radiation therapy to your head and neck

Complications of cavities

Without treatment, a cavity can lead to an infection. Rarely, the infection may spread from your mouth to lymph nodes in your neck.

How doctors diagnose cavities

A dentist may do dental X-rays to check for cavities. They may check your teeth for soft spots that are signs of cavities.

Cavity treatments

Treatments vary depending on your situation, but may include:

• Fluoride treatments: This is an option if tooth decay is just starting. The treatment can fix damaged enamel and stop cavities from forming. You may have fluoride treatments and use prescription toothpaste and mouthwash.
• Dental fillings: Your dentist uses a drill to remove decayed tissue and replace it with filling material. The filling may be composite, silver amalgam or gold.
• Root canal: This procedure treats advanced tooth decay. With a root canal, your dentist removes tooth pulp. Then, they replace the pulp with a special filling material. They may place a dental crown on your tooth.
• Tooth extraction: Your dentist may remove your tooth if you can’t have a root canal. You may need a dental bridge or dental implant to replace your tooth.

What can I expect if I have a cavity?

Treatment cures cavities. But another one can develop, especially if you don’t use good oral hygiene. You should also have regular dental checkups.

How do I prevent cavities?

Proper oral hygiene, including regular brushing and flossing, can get rid of bacteria, plaque and acid that damage your tooth enamel. Here’s how to take good care of your teeth and gums:

• Brush your teeth with a soft-bristled brush and fluoride toothpaste at least twice a day, and preferably after every meal.
• Floss daily to remove food and plaque stuck between your teeth.
• Cut back on sugary, starchy foods and drinks.
• Have dental checkups at least twice a year. You might need more frequent visits if you’re prone to tooth decay, gum disease or other oral health issues.
• Get dental sealants that protect the top chewing surfaces of your teeth.

What’s the difference between a cavity and a stain?

It’s easy to confuse cavities and stains because both change the color of your tooth. Here are the differences:

• Cavities are darker than stains.
• Stains tend to affect several teeth. A tiny spot on one tooth is likely a cavity.

Is it possible to heal a cavity?

Yes, fluoride treatments can heal a cavity that’s just beginning to form. Cavities start when your tooth enamel breaks down. Fluoride treatments repair damaged tooth enamel.

Does a toothache from a cavity mean it’s too late for treatment?

No, it doesn’t. You may have a toothache if decay reaches your tooth pulp. Your dentist may do a root canal to clean out decay. A toothache from a cavity means decay has spread to your tooth’s deeper layers.