Endodontics · single question
During endodontic cleaning and shaping of a necrotic tooth, the tooth suddenly begins to bleed. What is the MOST likely explanation?
Show answer and explanation
Correct answer: B. Sodium hypochlorite accident (hypochlorite extrusion)
A sodium hypochlorite (NaOCl) accident occurs when irrigant is inadvertently extruded beyond the apex into the periapical tissues. Hypochlorite is highly caustic and causes tissue necrosis, severe pain, swelling, and rapid bruising/ecchymosis. Bleeding from the socket during cleaning and shaping of a necrotic tooth (which should not bleed) indicates periapical tissue damage from hypochlorite extrusion — the bleeding is from injured periapical vessels and tissues. This is a dental emergency.