Diseases

Abscess:

An abscess is an enclosed collection of liquefied tissue, known as pus, somewhere in the body. It is the result of the body's defensive reaction to foreign material.

Odontogenic abscesses include a broad group of acute infections that originate from the tooth and/or the periodontium.
In a periodontitis patient a periodontal abscess represents a period of active tissue breakdown and is the result of an extension of the infection into the still intact periodontal tissues.

Classification:

The most rational classification of periodontal abscesses is, the one based on its etiology. Depending on the cause of the acute infectious process, two types of abscesses may occur:
Periodontitis-related abscess, when the acute infection originates from bacteria present at the subgingival biofilm in a deepened periodontal pocket.
Non-periodontitis-related abscess, when the acute infection originates from bacteria originating from another local source, such as a foreign body impaction or from alterations in the integrity of the root leading to bacteria colonization.

Mechanisms behind the formation of a periodontitis-related abscess:

Exacerbation of a chronic lesion. Such abscesses may develop in a deepened periodontal pocket without any obvious external influence, and may occur in:
An untreated periodontitis patient,
As are current infection during supportive periodontal therapy.
Post-therapy periodontal abscesses. There are various reasons why an abscess may occur during the course of active therapy:
Post-scaling periodontal abscess. When these lesions occur immediately after scaling or after a routine professional prophylaxis they are usually related to the presence of small fragments of remaining calculus that obstruct the pocket entrance once the edema in the gingiva has disappeared. Abscess formation can also occur when small fragments of calculus have been forced into the deep, previously uninflamed portion of the periodontal tissues.
Post-surgery periodontal abscess. When an abscess occurs immediately following periodontal surgery, it is often the result of an incomplete removal of subgingival calculus or to the presence of foreign bodies in the periodontal tissues, such as sutures, regenerative devices, or periodontal pack.
Post-antibiotic periodontal abscess. Treatment with systemic antibiotics without subgingival debridement in patients with advanced periodontitis may also cause abscess formation.


External local factor that explains the acute inflammatory process occurred in Non-periodontitis-related abscess. Such factors may include:
Impaction of foreign body in the gingival sulcus or periodontal pocket. It may be related to oral hygiene practices (toothbrush, toothpicks), orthodontic devices and food particles.
Root morphology alterations. In this instance local anatomic factors, such as an invaginated root, a fissured root, an external root resorption, root tears or iatrogenic endodontic perforations , may be the cause of the abscess formation.
Also periodontal abscess could be categorized according to its positionas:
Gingival abscess: Localized painful, rapidly expanding lesion involving the marginal gingiva or interdental papilla, it is an acute inflammatory response to foreign substance forced into the gingiva. In early stage appear as red swelling with a smooth, shiny surface, within 24-48 hours, the lesion is usually fluctuant and pointed with a surface orifice from where a purulent exudate may be expressed, the lesion ruptures spontaneously.
Periodontal abscess: Is a localized accumulation of pus within the gingival wall of a periodontal pocket resulting in the destruction of the collagen fiber attachment and the loss of nearby alveolar bone It is usually associated with:
Tortuous periodontal pocket.
Furcation involvement.
Infra bony defect.
Calculus is often detected in the root surface.
Pericoronal abscess: Localized accumulation of pus within the overlying gingival flap surrounding the crown of an incompletely erupted tooth, usually occur in the mandibular third molar area, the gingival flap appear red and swollen, patient usually have a history of pericoronitis and may experience difficulty in swallowing. The infection may spread to the oropharyngeal area and the base of the tongue and involve the regional lymph node.
Pathogenesis and histopathology:
It is hypothesized that the occlusion of the periodontal pocket lumen, due to trauma or tissue tightening, will prevent drainage and result in extension of the infection from the pocket into the soft tissues of the pocket wall, resulting in the formation of the abscess.
It is the accumulation of leukocytes and the formation of an acute inflammatory infiltrate what will be the main cause of the connective tissue destruction, encapsulation of the bacterial mass and formation of pus.
The histopathology of this lesion demonstrates, in its first phases, the central area of the abscess filled with neutrophils, in close vicinity with remains of tissue destruction and soft tissue debris. At a later stage, a pyogenic membrane, composed of macrophages and neutrophils, is organized. The periodontal abscess lesion contains bacteria, bacterial products, inflammatory cells, tissue breakdown products, and serum.
The rate of tissue destruction within the lesion will depend on the growth of bacteria inside the foci and their virulence, as well as on the local pH. An acidic environment will favor the activity of lysosomal enzymes and promote tissue destruction.

Microbiology:

These studies have shown that the microbiota of periodontal abscess is not different from the microbiota of chronic periodontitis lesions. This microflorais polymicrobial and dominated by non-motile, Gram negative, strict anaerobic, rod-shaped species. From this group, Porphyromonas gingivalis is probably the most virulent and relevant microorganism. The occurrence of P. gingivalis in periodontal abscesses ranges from 50–100%.
Other anaerobic species that are usually found include Prevotella intermedia, Prevotella melaninogenica, Fusobacterium nucleatum, and Tannerella forsythia. Spirochetes (Treponema species) are also found in most cases
Diagnosis:
The diagnosis of a periodontal abscess should be based on the overall evaluation and interpretation of the patient´s chief complaint, together with the clinical and radiological signs found during the oral examination.
symptom of a periodontal abscess:
The presence of an ovoid elevation of the gingival tissues along the lateral side of the root.
Abscesses located deep in the periodontium may be more difficult to identify by this swelling of the soft tissue, and may present as diffuse swellings or simply as a red area.
Suppuration, either from a fistula or, most commonly, from the pocket. This suppuration may be spontaneous or occur after applying pressure on the outer surface of the gingiva.
Pain (from light discomfort to severe pain).
Tenderness of the gingiva, swelling, and sensitivity to percussion of the affected tooth.
Tooth elevation and increased tooth mobility.
The radiographic examination may reveal either a normal appearance of the interdental bone or evident bone loss, ranging from just a widening of the periodontal ligament space to pronounced bone loss involving most of the affected root.
May be associated with elevated body temperature, malaise, and regional lymphadenopathy


Differential diagnosis:
Signs and symptoms indicating a more likely periodontal origin include:
A history of periodontal disease or previous periodontal therapy;
Clinical signs of deep periodontal pockets releasing pus;
Frequently a vital pulp response;
Radiographic findings of crestal bone loss frequently associated with angular bone defects and furcations.
signs and symptoms indicating a morelikely periapical (endodontal) origin will include:
A history of caries, restorative or endodontic therapy;
Clinical signs of questionable or lack of response topulp tests;
Presence of advanced caries lesions or restorations and the presence of a sinus tract;
The radiographic findings will usually evidence the presence of a periapical radiolucency associated with either a carious or restored tooth or an endodontically treated tooth showing more or less endodontic filling or endodontic or post perforations.

Treatment:

The treatment of the periodontal abscess usually includes two stages:
The management of the acute lesion,
The appropriate treatment of the original and/or residual lesion, once the emergency situation has been controlled.
For the treatment of the acute lesion, different alternatives have been proposed ranging from:
Incision and drainage,
Scaling and root planing,
Periodontal surgery,
The use of different systemically administered antibiotics ,( In principle, a high dose of the antibiotic delivered during a short period of time, is recommended. If the patient is recovering properly, the antibiotic should not be given for more than a 5-day period).


Complication:
Tooth loss: Periodontal abscesses have been suggested as the main cause for tooth extraction during the phase of supportive periodontal therapy.
Dissemination of the infection:
Dissemination of the bacteria inside the tissues during therapy.
Bacterial dissemination through the blood stream due to bacteremia from an untreated abscess.