Periapical abscess is a limited accumulation of purulent exudate in the tissues around the apical third of the tooth root. Patients complain of the occurrence of dull pronounced pain in the area of the causal tooth, an increase in soreness when biting off food, chewing. In the projection of the root tips with a periapical abscess, a hyperemic edematous mucosa is detected. Fluctuation is observed, vertical percussion is positive. Diagnostics includes collection of complaints, physical examination, radiography. Treatment is aimed at creating an outflow for purulent exudate, sterilization of root canals, restoration of bone structure, prevention of complications.
Periapical abscess is a complication that occurs with an exacerbation of the inflammatory–destructive process in the tissues of the apical periodontium, characterized by a limited accumulation of purulent exudate. Periapical abscess occurs with the same frequency in both men and women. The main group of patients are young people. Rich periodontal blood supply and well-defined metabolic processes contribute to the acute course of pathology. More often, a periapical abscess is diagnosed in the autumn-spring period. Five main types of microorganisms are found in the pathological focus, among which anaerobic rods and peptostreptococci occupy the leading positions. In 65% of cases, the bacterium Prevotella Intermedia is detected in the periapical abscess.
A periapical abscess develops as a result of infection of the root canals in acute periodontitis or in the case of exacerbation of a chronic destructive process. The main causes of inflammation of the apical periodontium include injuries accompanied by rupture of the neurovascular bundle, thermal overheating of the pulp during the preparation of vital teeth before prosthetics, toxic effects on the pulp of photopolymer materials with deep caries.
A periapical abscess can also occur due to infection of periodontal tissues with dentine tubules in violation of the protocol of endodontic treatment, as well as in the case of incomplete obturation of the channels with permanent filling material. Predisposing factors contributing to the development of periapical abscess include hypothermia and frequent infectious diseases that reduce the reactivity of the body.
When the pulp disintegrates, along with the infiltration of the walls of the root canal by bacteria and their toxins, the penetration of pathogenic microflora beyond the tip of the root is observed, which leads to the development of periodontal inflammation. Polymorphonuclear leukocytes are the first to rush into the pathological focus. Macrophages bind bacterial cells, activate the complement system, as a result, microcirculation is disrupted, vascular permeability increases.
The accumulation of mononuclear lymphocytes and macrophages leads to an abundant release of lysosomal enzymes that catalyze the activity of osteoclasts, which entails the destruction of the periodontium and adjacent tissues. Leukocyte infiltration contributes to the formation of microabsesses, with the fusion of which one abscess is formed. The histological picture in periapical abscess is represented by a site of tissue melting, a shaft consisting of neutrophils is observed along the periphery.
Classification and symptoms
According to the nature of the course , periapical abscesses are divided into 2 categories:
- Periapical abscesses with fistula. They develop as a result of a long course of the inflammatory-destructive process, while the granulation tissue grows into the bone marrow spaces and mucosa. It is possible to form a junction with the skin, maxillary sinus, nasal cavity, oral cavity. The disease has a chronic course.
- Periapical abscesses without a fistula. Occur due to transcanal infection of periodontal tissues. They are characterized by a pronounced clinic.
When forming a periapical abscess, patients complain of the appearance of intense dull throbbing pain in the area of the causal tooth. Unpleasant sensations increase when chewing. The configuration of the face with a periapical abscess changes due to the formation of swelling. If an abscess forms on the upper jaw, the opening of the mouth is not disturbed. In the absence of timely treatment of exacerbation of chronic periodontitis of the lower molars (wisdom teeth), the masticatory muscles are involved in the inflammatory process, resulting in contracture of the lower jaw. Patients indicate a restriction when opening the mouth, soreness when swallowing.
With a periapical abscess on the mucous membrane of the oral cavity, painful swelling is detected in the projection of the tips of the causal tooth. The symptom of fluctuation is positive. The transitional fold is smoothed. The mucous membrane is hyperemic. Vertical percussion is sharply positive. Periapical abscess is more often localized from the buccal side of the alveolar process. If the infection has penetrated into the periodontium from the palatine channels of the second premolars or molars, an abscess is found in the palate.
There may be a deep carious cavity or filling on the chewing surface of the causal tooth. The tooth is changed in color. With a periapical abscess, the regional lymph nodes are enlarged. The general condition is broken. Patients complain of malaise, headache, fever. With a periapical abscess with a fistula, the clinical picture is erased. As a rule, the causal tooth is gray. Vertical percussion is painful. Lukomsky’s symptom is positive. A fistula with granulations is detected on the mucosa.
Diagnosis of periapical abscess includes collection of complaints, anamnesis of the disease, physical examination, radiography, EOD, thermography. During the examination, the dentist reveals the facial asymmetry. The mucous membrane in the projection of the causal tooth with periapical abscess is hyperemic, painful. Fluctuation is observed. The vertical percussion is positive. A causal tooth with a periapical abscess can be destroyed, restored or covered with a crown.
In the case of a carious cavity, probing its walls and bottom with a periapical abscess is painless. When the pulp chamber is opened, putrid masses or filling material are determined in the root canals. In the chronic course of the disease, a fistula is found on the mucosa. Lukomsky’s symptom is positive. The pulp chamber has a connection with the carious cavity. In most cases, the causal tooth has been previously treated. The thermal test for periapical abscess is negative. EOD is used to determine the vitality of the pulp. The pulp sensitivity value in the range from 2 to 20 µA indicates its viability, an indicator from 20-100 µA signals the development of the inflammatory process. With periapical abscess, the results of EOD are at the level of 100 mcA and higher, which indicates the disintegration of the pulp with the involvement of periodontal tissues in the inflammatory process.
If a periapical abscess has formed during exacerbation of chronic fibrous periodontitis, the expansion of the periodontal gap in the apical third of the root is determined radiographically. A characteristic radiological sign of chronic granulomatous periodontitis is a site of destruction of rounded bone tissue with a diameter of up to 5 mm around the tip of the causal tooth. When a periapical abscess is formed against the background of chronic granulating periodontitis, destructive changes in the periapical zone with uneven contours resembling “flames” are revealed on a targeted radiograph. Root resorption may occur. Periapical abscess is differentiated with acute periodontitis, exacerbation of chronic periodontitis, periodontal abscess, periostitis, osteomyelitis, suppuration of the radicular cyst. A clinical examination is carried out by a dentist-therapist, a dentist-surgeon.
The primary task in identifying a periapical abscess is to ensure a full outflow for purulent exudate. For this purpose, the dentist creates access to the mouths of the channels, removes putrid masses, performs instrumental and drug treatment. The tooth remains open. In case of periapical abscess, the patient is prescribed soda-salt hyperosmotic oral baths, antibacterial drugs. Next, a test for “hermeticism” is carried out in dentistry. Root canals are sealed with a temporary calcium-containing paste. If a periapical abscess has arisen against the background of acute periodontitis, in the absence of exudation, the root canals are lined with a permanent filling material. In case of exacerbation of chronic periodontitis, calcium hydroxide-based pastes are changed every 3-4 weeks during the first 4-6 months. With positive X-ray dynamics, the channels are sealed.
Often, in the treatment of periapical abscess, a method is used in which, to prevent additional contamination of the root canals, the tooth is closed with a temporary seal after primary endodontic treatment. An antiseptic dressing is placed in the root canal, which, along with an antimicrobial drug, includes a hormonal agent. To relieve inflammation, antibiotics, nonsteroidal anti-inflammatory drugs are prescribed for oral administration. The transcanal effect on the pathological focus is carried out by introducing a calcium-containing paste into the periapical zone. For permanent obturation, gutta-percha pins are used together with a siller.
Drainage of the periapical abscess can also be carried out through an incision of soft tissues. In the absence of pathological destructive changes on the radiograph, the prognosis for periapical abscess is favorable. High-quality endodontic treatment eliminates an infectious focus in periodontal tissues. If a periapical abscess has arisen with an exacerbation of chronic granulating or granulomatous periodontitis, the prognosis largely depends on the age and immune status of the body. If conservative therapy of periapical abscess is ineffective, tooth-preserving operations (hemisection, resection of the apex) are performed. With an increase in inflammatory phenomena, the tooth must be removed.
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