The hardest root canal treatment

This was a 27 that needed a root canal. I started the treatment like any other root canal. As soon as I opened the access, I only saw a buccal and a lingual canal. This is not common but is a phenomenon that occurs on 2nd molars. I continued to clean and shape as normal. Just to rule out the presence of an extra canal, I took a cbct. To my surprised, there was a distobuccal canal in the same orifice of the buccal canal. Which means, the mesiobuccal and distobuccal are in the same orifice. This was extremely hard to negotiate and locate. But with the aid of my microscope, everything was possible