Case 37 Five canals more common than we think

Pre-operative x-ray #19

Patient presented with swelling and painful to bite.

Photo showing pulp chamber floor #19

Once the pulp chamber was clear, five canals clearly visible. Note: The fifth canal is usually in the isthmus area between distal buccal and distal lingual systems, if in the distal root. 

Post-operative x-ray #19

All canals were filled to the apex.

Comments: Usually if there are five canals you will find three in the mesial root more often than the distal root. Three canals in the either root are usually not three separate canals.  In my experience, a third canal either joins the  buccal or lingual canal system.  I can tell you from surgically treating first molars, that the isthmus area many times is the cause of periapical problems because the isthmus has not been or cannot be cleaned adequately.