The hard outer surface on your teeth is called the enamel. The pulp is deep inside the tooth and contains blood vessels and nerves. Bacteria can damage different parts of the tooth.
What are cavities?
Cavities are decayed parts of your tooth.
Bacteria build up on your tooth enamel and make acids that cause holes in the tooth—the holes are called cavities
Tooth pain happens as cavities get bigger and go through the enamel to the inside of your tooth
Dentists find cavities by looking at your teeth and taking x-rays
Treatment includes drilling out decay and filling the hole
Regularly brushing your teeth, getting dental check-ups, and avoiding sugary foods can help prevent cavities
What causes cavities?
Bacteria build up on your teeth and make acid that causes decay.
Bacteria, saliva (spit), and bits of food form a thin layer called plaque that clings to your teeth. Plaque hardens over time and turns into tartar. Tartar is usually yellow. You sometimes see it at the base of teeth. Bacteria living in plaque and tartar are hard to get rid of.
The bacteria thrive on sugar. That's why sugary foods and drinks can lead to cavities. The amount of sugar you eat is less important than the how often you eat sugar. What matters is the amount of time sugar is in contact with your teeth. Sipping a sugary soft drink over an hour is more damaging than eating a candy bar in 5 minutes, even though the candy bar may contain more sugar. Babies who go to bed with a bottle, even if it contains only milk or formula, are also at risk of cavities. Bedtime bottles should contain only water.
You’re more likely to get cavities if you:
Have a lot of plaque and tartar in your mouth
Eat and drink sugary or acidic foods, such as cola sodas or juice
Have too little fluoride (a mineral that makes your enamel harder) in your teeth
Don’t have much saliva (spit) in your mouth (a condition called dry mouth Dry Mouth Dry mouth is caused by a reduced or absent flow of saliva. This condition can cause discomfort, interfere with speech and swallowing, make wearing dentures difficult, cause bad breath (halitosis)... read more )
Have gums that have shrunk down the bottom of your teeth (receding gums)
What are the symptoms of cavities?
A shallow cavity in your enamel doesn't hurt. Cavities that are a little deeper may cause pain when you eat hot, cold, or sweet foods or drinks.
A cavity that gets deep enough to reach the pulp causes pulpitis Pulpitis The hard outer surface on your teeth is called the enamel. The pulp is a softer layer deep inside the tooth. The pulp contains the tooth's blood vessels and nerves. Pulpitis is painful inflammation... read more . Pulpitis causes toothache even when you’re not eating or drinking. If the pulp gets infected, you may develop a pocket of pus called a dental abscess Dental Abscess An abscess is a collection of pus. Pus is a mix of white blood cells, dead tissue, and bacteria. It builds up wherever your body is fighting an infection. A dental abscess is an abscess that... read more .
How can dentists tell if I have cavities?
Dentists diagnose cavities by:
Looking at your teeth and probing them with dental tools
Taking x-rays of your teeth
How do dentists treat cavities?
If your cavity is very small and only on the enamel, the tooth can fix itself if you have enough fluoride.
Dentists treat cavities that are deeper than the enamel by drilling out the decayed part of the tooth and putting in a filling. The filling can be made of:
Silver amalgam (a combination of silver, mercury, copper, tin, and sometimes other metals), often used in back teeth where it will be out of sight
Composite resins, which match the color of your teeth
Glass ionomer, which is tooth-colored and releases fluoride, good for people with a lot of tooth decay
Root canal treatment or tooth removal
When tooth decay goes deep enough to reach the pulp and it becomes severely inflamed, dentists will give you pain medicine and either:
Do a root canal to remove the pulp from your tooth and then fill and seal the tooth canal
Take out the tooth if it can't be saved
If you have an infection, they'll also give you antibiotics.
How can I prevent cavities?
You can prevent cavities by:
Brushing your teeth with toothpaste that contains fluoride (in the morning and evening and after eating sugary foods)
Flossing your teeth daily
Getting regular dental care
Eating healthy foods and cutting back on food and drinks that have a lot of sugar or acid
It's important to get enough fluoride. Fluoride is a mineral that protects your teeth from cavities. Fluoride is added to the public water supply in some areas. If it's not in your water, the dentist may prescribe fluoride supplements for children up to age 8, or apply fluoride treatments to your teeth.
If you still get a lot of cavities, dentists may:
Put sealants on your teeth (sealants are a hard plastic coating that prevent cavities in teeth with deep crevices)
Have you use an antibacterial mouth rinse that helps kill cavity-causing bacteria