Periapical Abscess: Tooth Infection, Pus Formation, and Treatment

A periapical (dental) abscess is a pus-filled infection at the root apex, caused by bacterial invasion of the pulp through caries, crack, or trauma.

Pathophysiology

Bacteria → pulp necrosis → toxins exit apical foramen → periapical inflammation → abscess formation. Can spread to fascial spaces (cellulitis, Ludwig's angina).

Symptoms

• Severe, throbbing toothache (worsens with pressure/heat)
• Swelling (gingival, facial)
• Fever, malaise (if spreading)
• Purulent drainage (fistula/sinus tract)

Treatment

• Definitive: Root canal therapy (debridement, disinfection, obturation) or extraction
• Adjunct: Incision & drainage for fluctuant swelling; antibiotics for systemic signs (fever, spreading cellulitis, immunocompromise)

Urgent dental care prevents complications.