What is a tooth abscess?

A tooth abscess is a collection of pus around an infected tooth. There are two types of dental abscess:

• a pus-filled sac at the root of a tooth

• a pus-filled sac between the gum and a tooth.

How does it occur?

An abscess at the root is usually caused by severe tooth decay. When decay reaches the inside or pulp of a tooth, which contains the nerves and blood supply, the pulp dies. The infection in the pulp spreads from the tip of the root to the surrounding bone.

An abscess at the root can also be caused by injury to a tooth, such as a severe blow to the tooth or jaw.

An abscess between a tooth and gum usually forms when bacteria and food become trapped in an area that is hard to clean.

Sometimes the cause of an abscess is unknown.

What are the symptoms?

Possible symptoms of an abscess are:

• sensitivity to heat and cold

• a lingering ache

• throbbing, particularly if it occurs without apparent cause and is unrelated to biting or chewing

• pain on biting or chewing

• redness and swelling of the gums

• discolored tooth

• tender glands in the neck

• swollen face

• a bad taste

• foul drainage

• an open, draining sore on the side of the gum.

How is it diagnosed?

To diagnose a dental abscess, your dentist will examine your teeth and usually order x-rays to check for any disease.

The dentist may use ice or an electric tester to check the health of a tooth. An electric tester uses a small amount of electrical current to stimulate the nerve. A normal tooth will feel sensitive to the ice or the electrical stimulation but will feel relief when the dentist removes the ice or current. A tooth with an irritated nerve will feel some sensation even when the dentist removes the ice or current. A dead tooth will not feel any sensation at all.

Your dentist may slide a probe gently down the side of the tooth to check for pocketing. If an abscess exists, this procedure may release some of the pressure from built-up infection, but the pocket will have to be fully cleaned out to remove pus and debris.

How is it treated?

Abscess at the Root of a Tooth:

Root canal therapy is the usual treatment for an abscess at the root of a tooth. A general dentist or an endodontist (a specialist in this therapy) may perform a root canal.

If the tooth is not dead, the dentist will inject a painkiller, which makes the area numb. The dentist then drills a small opening in the top of the tooth and uses small files to clean out dead tissue and bacteria from the tiny canals. The canals are washed with special solutions. The dentist may use a soft, temporary filling to seal the clean canals.

At another appointment, the dentist will seal each canal and put a permanent filling on the chewing surface of the tooth. Most often, the dentist will recommend a crown to protect the tooth from breaking, since a tooth treated with root canal therapy may break more easily.

If the infection persists, additional treatment is necessary. Your dentist may refer you to a specialist (an oral surgeon) who may surgically remove the diseased tissue.

When root canal or surgery is not possible, the dentist may have to pull the tooth. You may then need to wear an implant, a bridge, or a partial denture to replace the lost tooth.

Abscess Between the Gum and a Tooth:

Dentists usually treat this kind of abscess by first draining the infection, then thoroughly cleaning the area. The dentist then smoothes out the root surfaces of the tooth to promote healing and to help keep the infection from recurring. Before doing this procedure, your dentist may inject a painkiller to numb the gum and tooth.

Your dentist may recommend a follow-up x-ray of the tooth in 6 months to see how well the bone is healing and if the infection has cleared up.

Your dentist may recommend gum surgery to help heal an abscess between the gum and a tooth. This surgery, often performed by a periodontist, involves surgically reshaping the gum tissue to make a shallow area that is easier to keep clean and free from infection.

How long will the effects last?

The effects of an abscessed root last as long as it is untreated. An infection that spreads from the tip of the root builds up pressure and destroys the surrounding bone. This destruction continues until the pressure is released by root canal therapy, or until the infection destroys enough bone so that it can drain out near the tooth, creating a gumboil on the tissue. The body continues to fight the build-up of pus and bacteria.

An abscess between gum and tooth will generally heal soon after the abscess has been drained and the root surfaces cleaned. However, the abscess may recur if the area is not kept clean. Your dentist or dental hygienist may recommend the use of special tools to make cleaning these areas easier.

How can I take care of myself?

Follow your dentist's instructions and take the full course of any antibiotics prescribed. In addition, you can:

• Rinse your mouth three to four times a day with warm salt water.

• Chew on the side that does not have the affected tooth or tissue.

• Keep your mouth as free from bacteria as possible by brushing frequently and flossing daily.

• Follow any special instructions given to you by your dentist or dental hygienist.

• Keep any follow-up appointments with your dentist.

What can be done to prevent the spread of a dental abscess?

To prevent the spread of an abscess, see your dentist for treatment.

The best way to prevent an abscess is to visit your dentist twice a year. At these appointments, your dentist and dental hygienist will:

• X-ray your teeth once a year to check for decay between the teeth and to evaluate the health of your jaw bone.

• Examine your teeth and mouth.

• Remove any plaque and tartar that have built up on your teeth.

• Teach you how to care for your teeth and maintain good oral health.

• Alert you to any problem areas.

• Recommend any needed treatments.