Phoenix abscess is an acute flare-up of a previously chronic periapical infection (usually around a tooth with a necrotic pulp or incomplete root canal treatment).
What exactly happens?
It’s like a “sleeping” infection suddenly becoming active again. A tooth that may have been relatively symptom-free develops sudden pain and swelling due to renewed bacterial activity and immune response.
Key features
Sudden severe pain
Swelling near the affected tooth
Tooth becomes tender to biting/percussion
May have pus formation
Usually associated with a non-vital tooth
Often occurs during or after root canal treatment
Why does it occur?
Common triggers include:
Disturbance of bacteria during root canal procedures
Incomplete cleaning of root canals
Reduced host resistance
Changes in microbial balance
Radiographic findings
Pre-existing periapical radiolucency (chronic lesion already present)
How is it managed?
Drainage (through root canal or incision if swelling present)
Continue/complete root canal treatment
Occlusal reduction (to relieve biting pressure)
Analgesics for pain
Antibiotics (only if systemic signs like fever or diffuse swelling)
