Causes - Phoenix abscesses are believed to be caused by changes in the internal environment of the root canal system during root canal treatment. - These changes can lead to a sudden worsening of symptoms of chronic periradicular periodontitis. - Instrumentation during root canal treatment can stimulate residual microbes in the root canal space, causing an inflammatory reaction. - The microbes involved are predominantly facultative anaerobic gram-positive bacteria, such as Streptococcus, Enterococcus, and Actinomyces species. - Another cause of a phoenix abscess is a decrease in a patient's resistance to these bacteria and their products.

Signs & Symptoms - Exacerbated and exaggerated pain is a common clinical feature of a phoenix abscess. - Pain may or may not be associated with pus and suppuration. - The signs and symptoms are similar to those of an acute periradicular abscess, with the presence of a periradicular radiolucency. - The affected tooth will have a non-vital pulp with no previous symptoms. - The tooth is extremely tender to touch and may be extruded from the socket, leading to high occlusion. - Mobility of the tooth may be observed. - Radiographically, a periapical lesion associated with the tooth will be visible. - This lesion is usually present prior to the onset of the phoenix abscess. - A widened periodontal ligament (PDL) space can be seen on the radiograph.

Treatment - Further root canal treatment is often the recommended option for treating a phoenix abscess. - The tooth should be accessed and thoroughly irrigated using sodium hypochlorite. - After irrigation, the canals should be dried using paper points. - Debridement of the tooth should be performed, and drainage should be established. - Antibiotics may be necessary in certain circumstances, such as the presence of diffuse swelling or cellulitis. - Antibiotics may also be indicated when immediate drainage cannot be achieved or when the patient has systemic involvement. - Analgesics may be advised to control pain associated with a phoenix abscess. - If the tooth is unrestorable, extraction may be considered as a treatment option for a phoenix abscess. - Adjusting the bite may provide temporary relief, but it is not a permanent solution to the problem.

References - Classification of Pulpal and Periradicular Pathoses «UCLA School of Dentistry Clinic Guide. - Sakko, Marjut; Tjäderhane, Leo; Rautemaa-Richardson, Riina (2016-05-01). Microbiology of Root Canal Infections. - Carrotte, P (September 2004). Endodontics: Part 3 Treatment of endodontic emergencies (PDF). - McClanahan, Scott B (2002). Pulpal and Periradicular Diagnostic Terminology (PDF). - Shetty, Neeta. Mid Treatment Flareups in Endodontics (PDF).

Subtopics (not included in the previous groups) - SUBTOPIC 2.1: Clinical Features - SUBTOPIC 2.2: Radiographic Features - SUBTOPIC 3.1: Further Endodontic Treatment - SUBTOPIC 3.2: Medications - SUBTOPIC 3.2.i: Antibiotics - SUBTOPIC 3.2.ii: Analgesics - SUBTOPIC 3.3: Extraction - SUBTOPIC 3.4: Bite Adjustment