May also be called: Acute Dentoalveolar Abscess, Acute Apical Dental Abscess, Acute Dental Abscess, Apical Abscess, Tooth Abscess, Dental Abscess, Periapical Infection, Tooth Infection, Abscessed Tooth A periapical (per-ee-AP-ih-kul) abscess is a collection of infected material (pus) that forms at the tip of the root of a tooth. More to Know Periapical abscesses form after bacteria enter the tooth and cause an infection in the pulp — the innermost portion of the tooth that consists of connective tissue, nerves, and blood vessels. This is usually the result of tooth decay or an injury that causes the tooth to chip or crack. When the pulp becomes infected, the body's immune system sends white blood cells to fight the infection. It's these white blood cells, along with other debris, that can form a collection of pus near the tiny hole (apical foramen) that sits at the tip of the root of the tooth. Periapical abscesses can cause severe tooth pain and sensitivity to temperature; a fever; pain while chewing; and swelling in the gum, glands of the neck, and upper or lower jaw. Treatment for a periapical abscess can involve antibiotic medications, draining the abscess, or performing root canal surgery to save the tooth. In rare cases, the tooth may have to be pulled. Keep in Mind If left untreated, periapical abscesses can get worse and cause serious complications. In many cases, however, prompt treatment can cure the infection and save the affected tooth. Practicing good dental hygiene can reduce the risk of a periapical abscess. All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts. Back to Articles Related Articles A to Z: Abscess An abscess is a collection of pus that forms as part of the body's response to an infection. Read More Gum Disease Gum disease doesn't just happen to people your grandparents' age - it can happen to teens too. Get the details here. Read More What Causes Bad Breath? Bad breath, or halitosis, can be a major problem, especially when you're about to snuggle with your sweetie or whisper a joke to your friend. The good news is that bad breath often can be easily prevented. Read More Going to the Dentist What happens when you go to the dentist? Find out in this article for kids. Read More Peritonsillar Abscess A peritonsillar abscess is an area of pus-filled tissue at the back of the mouth, next to one of the tonsils. Find out how it happens and what to do. Read More Peritonsillar Abscess Older kids and teens with tonsilitis sometimes develop this painful abscess, a pus-filled tissue at the back of the mouth. Read More Taking Care of Your Teeth The healthier your teeth are, the happier you look. That's why it's important to take great care of your teeth by brushing, flossing, and visiting the dentist. Learn more. Read More Abscess People can get abscesses on the skin, under the skin, in a tooth, or even inside the body. Most abscesses are caused by infection, so it can help to know what to do. Find out in this article for teens. Read More Taking Care of Your Teeth There's a lot more to taking care of your teeth than breath mints and mouth sprays. Read this article to learn the facts on flossing, how to give plaque the brush-off, and much more. Read More Mouth and Teeth Our mouth and teeth play an important role in our daily lives. Here's a course on the basics - including common problems of the mouth and teeth. Read More Abscess An abscess is a sign of an infection, usually on the skin. Find out what to do if your child develops one. Read More Keeping Your Child's Teeth Healthy Here are the basics about how to care for your child's teeth - and when. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.