A dental abscess is a localized collection of pus in a cavity formed by the disintegration of tissues from a bacterial infection.
Dental abscesses occur when a small area of tissue becomes infected and the body is able to "wall off" the infection and keep it from spreading. White blood cells, the body's defense against some types of infection, migrate through the walls of the blood vessels in the area of the infection and collect within the damaged tissue. During this process pus forms, which is an accumulation of fluid, living and dead white blood cells, dead (necrotic) tissue and bacteria, or any other foreign invaders or materials; popcorn hulls, calculus, etc. This pus pocket is the abscess, characterized by swelling, redness, and pain.
The swollen area can rupture, allowing the pus to drain, but it will return if the cause of infection is not removed. As an abscess develops, the bacteria and host cells cause rapid destruction of connective tissues around the tooth and into the jawbone. Abscesses can be acute or chronic, with the acute abscess being the most painful. A chronic abscess may produce a dull pain with intermittent swelling, but can develop into an acute abscess at any time.
The most common types of dental abscesses are:
- Periapical abscess: located at the apex of an infected tooth surrounding the roots.
- Periodontal abscess: located in the periodontal ligament (PDL) surrounding the tooth.
Studies by the American Academy of Periodontology (AAP) find that periapical abscesses can occur on any tooth that has severe decay or is broken or chipped, but periodontal abscesses commonly involve the mandibular and maxillary first molars, maxillary incisors, and cuspids, followed by maxillary second molars.
Causes and symptoms
Periapical abscesses usually result from dental caries that allow bacteria to infect the center area of the tooth (pulp). But they can also occur after a traumatic injury to the tooth resulting in necrosis (death) of the pulp. This infection may spread out from the root of the tooth to the bones supporting the tooth, causing an abscess. This type of abscess is extremely painful and very sensitive to cold and hot, and to the touch. Acute inflammation of the apex commonly occurs with the tooth seeming to be slightly extruded from its socket. The patient may also have a fever and redness of the cheeks and gum tissue. The abscess itself may feel hot and hard to the touch. The bigger the abscess gets, the more painful it becomes.
A periodontal abscess occurs where pre-existing periodontitis is present. This infection occurs in the walls of the periodontal pocket as a result of bacterial invasion into the periodontal tissue. While abscesses usually spontaneously occur in patients with untreated periodontitis, they are more common in periodontitis patients with a systemic disease, in which there is a reduced ability to combat infections, such as individuals with diabetes or HIV, or patients on chemotherapy.
Periodontal abscesses are generally not sensitive to heat, and the pain is not as severe as with a periapical abscess, but the discomfort level is constant. They appear red, edematous (swollen), shiny, and very sensitive to the touch.
Other symptoms of a dental abcess include:
- general ill feeling
- bad breath or foul taste in mouth
- continuous or throbbing pain
When a patient has swelling and pain it is necessary to locate the exact region causing the pain. X rays greatly aid in locating the tooth or teeth in question. Hot and cold tests may be performed by touching the teeth with ice or heated instruments. This helps to pinpoint the exact location of the pain and to determine the type of abscess. Percussion tests may also be done by tapping the teeth in question lightly with the small end of an explorer. After diagnosis, the general dentist may choose to treat the abscess, but may also refer the patient to an endodontist or periodontist. The entire treatment may take a number of visits to complete depending on the severity of the abscess.
The cost for treatment of a periapical abscess is normally covered under dental insurance at 80%. The cost is usually a few hundred dollars or more if the patient is referred to an endodontist because of the specialty field. The insurance then only covers a certain amount of the usual and customary charge (UCR), commonly about 50%. A patient has to consider whether to have a general dentist treat the abscess, or whether to pay the extra cost to have a specialist perform the treatment. Usually having a specialist treatment the abscess is worth the extra cost in the long run.
For a periodontal abscess, a dental hygienist may perform the necessary scaling and root planing required to treat this condition. The cost for periodontal abscess treatment is commonly covered by dental insurance at 80%. Even when treated by a periodontist, insurance normally covers the treatment at 80% because a periodontal abscess is considered part of the periodontal disease for which the patient is already being seen by the specialist.
The goal of treating a dental abscess is to eliminate the infection while preserving the teeth and to prevent any complications. Releasing the direct pressure of the infection build up is the first step in the treatment.
With a periapical abscess, the pus is drained through an incision in the gum tissue, or by enlarging the hole in the tooth. This alleviates the pain and the tissue swelling. During this process the patient is given a local anesthetic to minimize the pain. Often with a periapical abscess, the infection is severe and pain is so intense that the anesthetic is injected into the tooth or infected area for immediate relief. Extraction of the tooth is sometimes required, especially if an injury to the tooth has fractured through the bifurcation area and saving the tooth is not possible.
The principle treatment for a periodontal abscess is to establish drainage of the inflammation and to eliminate the infective agent. Anesthetics are required because of the pain involved and the discomfort caused by scaling and root planing. Careful insertion of a dull probe into the pus pocket along the tooth will usually produce the drainage needed and the symptoms normally dissipate. Scaling and root planing through the periodontal pocket to rid the area of the cause of the infection is necessary.
If necessary, surgical procedures may be undertaken. Surgery aims at pocket reduction if not elimination. An incision into the gum tissue and the laying open of a flap of tissue may be necessary in order to reach the infection more easily. Surgery must be gentle and efforts are made to avoid damage to the remaining periodontal attachment. As soon as the etiologic factors have been eliminated the swelling is reduced.
The healing process is usually uneventful and regeneration frequently occurs. The abscess will recur unless the cause of the infection is removed and the depth of the pocket is reduced. Extraction of the tooth is indicated after the acute symptoms have subsided, but in some cases, normal tissue contours cannot be developed and maintained.
In cases where the periodontal destruction approaches the periapical region of the tooth (the apex) the patient may develop pulpitis. Treatment may cause the patient to experience pain and discomfort following the root planing treatment and treatment for pulpitis will need to be completed, usually with root canal therapy.
Antibiotics are vital in ridding the system of any infection for both periapical and periodontal abscesses. If the infection is not eliminated the abscesses will recur with a stronger infection and more severe symptoms.
The types of antibiotics prescribed for acute abscesses include:
- Penicillin VK: an initial dose of 1000 mg followed by 500 mg four times daily for seven days.
- Amoxicillin (Augmentin): 250 mg three times daily for ten days.
- Erythromycin: 1000 mg first followed by 500 mg four times daily for seven days (for patients allergic to penicillin).
For chronic infections or infections with an inadequate response to penicillin, clindamycin is often prescribed (300 mg daily for seven days).
Warm salt-water rinses can soothe the gum tissue and help with the healing process. Over-the-counter medication can be taken for pain along with the antibiotics. Medications such as acetaminophen (Tylenol) reduce fever (if any) and pain. Anti-inflammatory medicines such as ibuprofen (Motrin and Advil) aid in reducing fever and also help reduce swelling and inflammation in the tissue.
While the loss of periodontal attachment is commonly rapid during an acute periodontal abscess, the potential for repair and healing is very high if the abscess is treated quickly and appropriately. The prognosis for a periapical abscess is similar, if it is treated quickly and appropriately with the elimination of the infection that is causing the abscess.
Health care team roles
The role of the dentist is vital in combating the infection of a dental abscess. The patient needs to be educated that abscesses and infections of the mouth do not subside on their own without recurrence. An endodontist should be consulted if a periapical abscess needs to be treated. A periodontist should be consulted if an existing condition of periodontitis is being treated. Each type of dentist needs to have a good working relationship with the patient.
The dental hygienist can complete the scaling and root planing of the abscessed area in the dental office or the periodontist's office. Dental assistants can aid in taking x rays of the area needing treatment and in sterilization of the instruments. The front desk is the first to greet a patient and the last to see a patient leave. Having a warm and courteous front office is vital to any dental office where treating disease, emergencies, and healing of patients is accomplished. All roles are important to the successful functioning of the health care team and good patient care.
Dental abscesses can be prevented with regular dental care, including daily brushing and flossing, and regular dental check ups and cleaning. Wearing mouth guards during sports is one of the best ways to prevent an injury and trauma to the mouth.
Acute—Extremely sharp or severe, reaching a crisis rapidly.
Apex—The point at the end of the root of a tooth in the gum tissue.
Bifurcation—The area where the roots of the teeth separate into individual roots.
Calculus—Calcium deposits on teeth from the build up of plaque.
Chronic—Of long duration or frequent recurrence.
Cuspids—The teeth that are considered the cornerstone teeth of the mouth on the upper and lower jaws. More commonly known as the "eye" teeth.
Dental caries—Dental decay.
Edematous (edema)—An abnormal accumulation of serous fluid in the tissue.
Endodontist—A dentist who specializes in the diagnosis and treatment of disorders affecting the inside structures of the tooth.
Extraction—Surgical removal of a tooth.
Incisors—The teeth on the upper jaw right and left sides that sit next to the central front teeth.
Mandibular—Relating to the lower jaw region.
Maxillary—Relating to the upper jaw region.
Necrotic, necrosis—Pathologic death of tissue.
Periodontal—Tissue and structures that surround and support the teeth.
Periodontist—A dentist with specialized training for periodontal treatment and care.
Pulpitis—Inflammation of the pulp of a tooth involving the blood vessels and nerves.
Root canal—The space within a tooth that runs from the pulp chamber to the tip of the root.
Root canal therapy—The process of removing diseased or damaged pulp from a tooth, then filling and sealing the pulp chamber and root canals.
Root planing—Making the tooth smooth by removing built up calculus and tartar from below the gum tissue.
Scaling—The removal of food and debris from the portion of the tooth above the gum line.
Prosthodontist—A dentist with specialized training in crown and bridge treatment.
Physicians Desk Reference. Montvale, NJ: Medical Economics, 2000.
Meng, Huan X. "Periodontal Abscess." Journal for Periodontology 4 (December 1999): 79-82.
American Academy of Periodontology, 4157 Mountain Road, PBN 249, Pasadena, MD 21122. (410) 437-3749. <http://www.perio.org>.
American Dental Association (ADA), 211 East Chicago Avenue, Chicago, IL 60611. (312) 440-2500. <http://www.ada.org>.
American Institute for Preventive Medicine, 1431 Saratoga Ave. Suite C-9, Morgantown, VW 26505. (304) 599-6981. <www.peiapathways.com>.
UCLA School of Dentistry, 10833 Le Conte Ave. Box 951668, Los Angeles, CA 90095-1608. (310) 825-2337. <www.dent.ucla.edu>.
Marais, J.T. "What Is a Dental Abscess?" Electronic Doctor, December 1999. <www.edoc.co.za/dhw/faq/abscess.html>.
"Oral Health Topic: Abscess." ADA.org, January 2, 2001. <www.ada.org/public/topics/abscess.html>.
"Periodontal Abscess." UCLA Dental School, 2001. <www.dent.ucla.edu.81/pic/courses/antibiotics/abscess/>.
Cindy F. Ovard, RDA