Periodontal Abscess


The periodontal abscess is an acute destructive process in the periodontium resulting in localized collections of pus communicating with the oral cavity through the gingival sulcus or other periodontal sites and not arising from the tooth pulp. It is localized acute bacterial infection confined to the tissues of the periodontium. It is the third most frequent dental emergency, representing 7–14% of all dental emergencies and affecting 6–7% of all patients 1. It is formed as a result of rapidly-growing bacteria within a periodontal pocket resulting in abscess formation. It is a frequent periodontal condition in which periodontal tissues may be rapidly destroyed. Periodontal abscesses may result in complications, due to bacteremia, that may cause infection in distant-locations 2-3. Periodontal abscess is different from periapical abscess as the later has pulpal origin of infection. Following images demonstrate the clinical presentation of  periodontal and periapical abscess.

Periodontal abscess

Periodontal abscess

Periapical abscess

Periapical abscess

Clinical features:

Periodontal abscess may be acute or chronic in its onset. An acute exacerbation in chronic cases can be seen in some cases. The clinical features of periodontal abscess include,

  • Patient complains of pain which is throbbing in acute periodontal abscess and dull and gnawing in chronic periodontal abscess.
  • Edema and redness at effected site.
  • The involved tooth is sensitive on percussion.
  • Increased mobility of the effected tooth.
  • Increased probing depth. Bleeding or purulent exudates on probing.
  • Suppuration can be spontaneous or may be present on putting lateral pressure on involved surface of gingiva.
  • Draining sinus may be present.
  • Bone loss which can be seen in radiographic examination in chronic cases.
  • In delayed cases of periodontal abscess patient may have lymph node enlargement, fever and malaise.


Diagnosis of periodontal abscess is made depending upon the chief complaint of the patient, medical/dental history of the patient and clinical and radiographical examination. Development of periodontal abscess is usually associated with pre-existing periodontitis. Drainage of abscess may be spontaneous with slight provocation. It is important to note that periodontal abscesses not always drain from the same surface of root where periodontal pocket is present. Further, radiographic examination and status of the pulp provides important information regarding swelling. Radiograph taken with a gutta percha cone gently guided into the periodontal pocket to the site of abscess may provide an idea regarding the origin of abscess. A radioleuscency on the lateral surface of the root suggests periodontal abscess, although it may not be present in many cases (acute periodontal abscess). Widening of periodontal ligament can be seen in involved tooth.

Classifications of periodontal abscess 1,4:

1) According to anatomical location:

Gingival abscess: In this case abscess involves the marginal gingiva or the interdental papilla.

Lateral periodontal abscesses/ parietal abscesses: In this case abscess is present adjacent to the periodontal pocket that may lead to the destruction of the periodontal ligaments and the alveolar bone.

Combined periodontal/ endodontic abscesses: In this case the localized, circumscribed abscess which either originates from dental pulp or the periodontal tissues surrounds the involved tooth root apex and/or the apical periodontium.

Pericoronal abscesses: This is localized purulent infection within the tissue surrounding the crown of a partially erupted tooth.

2) Classification according to duration of the disease:

Acute periodontal abscess:

When the abscess develops during a short period of time within days or a week, it is called as acute periodontal abscess. There is sudden onset of pain on biting and a deep throbbing pain in involved tooth. The gingiva appears red, swollen and tender 5-6. In the early stages, there is no fluctuation or pus discharge, but as the disease progresses, the pus and discharge from the gingival crevice become evident. Lymph node enlargement may be evident as the duration of infection prolongs. 

Chronic periodontal abscess:

In this case the infection is of prolonged duration and the abscess develops slowly. Because of prolonged duration the involved tooth may become mobile and tender. Pain is usually of low intensity as compared to acute periodontal abscess. Pus may be present and discharges from the gingival crevice or from a sinus in the mucosa overlying the affected root.

3) According to etiology:

Periodontitis related abscess: When acute infections originate from a biofilm ( in the deepened periodontal pocket).

Non-Periodontitis related abscess: When the acute infections originate from another local source eg. Foreign body impaction, alteration in root integrity.

4) According to number of abscesses:

Single abscess: Abscess confined to a single tooth.

Multiple abscesses: Abscess confined to more than one tooth.

Periodontal abscess usually develops in association with moderate to deep periodontal pockets 7-8. Other etiological factors include incomplete calculus removal, embedding of foreign body, uncontrolled diabetes mellitus,tooth perforation or root fracture.

Etiology of periodontal abscess:

Periodontitis related abscess:

  • Deep and tortuous periodontal pockets 1.
  • Marginal closure of a periodontal pocket that may lead to an extension of the infection into the surrounding periodontal tissues due to the pressure of the suppuration inside the closed pocket 9-11.
  • The changes in the composition of the microflora, bacterial virulence or in host defenses could also make the pocket lumen inefficient to drain the increased suppuration 12.
  • Treatment with systemic antibiotics without subgingival debridement in patients with advanced periodontitis may also cause abscess formation 13-15.

Non periodontitis related abscess:

  • Due to impaction of foreign bodies such as a piece of dental floss, a popcorn kernel, a piece of a toothpick, fishbone, or an unknown object 16-18.
  • Perforation of the tooth wall by an endodontic instrument 1,19.
  • Due to infected lateral cysts 12.
  • Anatomical factors affecting the root morphology like presence of cervical cemental tears may also predispose to periodontal abscess formation 20-22.

Note: Multiple periodontal abscesses are usually associated with increased blood sugar and with an altered immune response in diabetic patients. Therefore, the assessment of the diabetic status through the testing of random blood glucose, fasting blood glucose or glycosylated haemoglobin levels is mandatory to rule out the aetiology of the periodontal abscess.

Micro-biology of periodontal abscess:

The periodontal abscess microbiota is usually indistinguishable from the microflora found in the subgingival plaque in chronic periodontitis 11. It has been reported that reported that around 60% of cultured bacteria from periodontal abscess are strict anaerobes especially gram-negative anaerobic rods and gram-positive facultative cocci 11. Fusobacterium spp., P. intermedia/nigrescens and P. gingivalis are the most prevalent microorganisms associated with periodontal abscesses 11,15,23. Other organisms found in periodontal abscess include T. Forsythia 24, A. Actinomycetemcomitans 25-26, Micromonas micros 26, Campylobacter rectus 24, Prevotella Melaninogenica 11. One study has proposed presence of enteric and nonfermenter Gram-Negative rods in periodontal abscess which according to the authors have a potential role in the rapid tissue destruction observed in periodontal abscesses 26. Studies have demonstrated that bacterial species with capacity of producing proteinases, such as P. intermedia may increase the availability of nutrients and thereby, increasing the number of bacteria inside the abscess 27-28

Differences between gingival and periodontal abscess

Gingival abscess Periodontal abscess
Limited to marginal gingiva and interdental papilla. Usually involves attached gingiva. 
Caused by bacteria being carried deep into the tissues when a foreign substance like a toothbrush bristles is forcefully embedded in the gingiva Caused due to the localization of inflammation because of one of the underlying reasons:

  • Extension of infection to lateral wall of pocket
  • Extension of infection deep into the supporting periodontal tissues.
  • In the deep end of a spiral or complex pocket
  • Incomplete removal of calculus leads to shrinkage of the gingival wall and occludes the opening of the pocket.
  • Due to perforation through the root during endodontic therapy.

Differences between periodontal and periapical abscess

Periodontal abscess

Periapical abscess

Periodontal pocket is present Caries/fracture is present
May occur after periodontal treatment. May occur after endodontic or restorative treatment.
Tooth is vital Tooth is non-vital
Pain is usually dull and localized (easy to localize due to the presence of tactile fibers in the periodontal ligament) Pain is severe and difficult to localize (difficult to localize as pulp basically consists of only pain perceiving fibers)
Swelling is present on the lateral surface of root usually without fistulous track as abscess usually drains from pocket opening. Swelling is present at the apical portion of tooth which drains by formation of a fistulous track.
Tender on lateral percussion Tender on vertical percussion
Usually not visible on the radiograph Appears as a periapical radiolucency
Responds to periodontal treatment Does not respond to periodontal treatment

Treatment of periodontal abscess:

For treatment of periodontal abscess please go to ” Treatment of periodontal abscess”  link.


Periodontal abscess is a relatively common condition in patients with moderate to deep pockets. It needs to be differentiated from periapical and gingival abscess. Also conditions like poorly controlled diabetes may lead to multiple abscesses for which the underlying cause needs to be treated. No specific organism has been found to be particularly associated with periodontal abscess; instead it is close to organisms found in deep periodontal pockets. Patients usually presents with pain and discomfort. Drainage of abscess and removal of etiological agent is required for healing of involved tooth supporting structures.


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