We all know root canal treatment is a lengthy and not cheap procedure, but shouldn't be a painful procedure. Root canals can be narrow and take long time to get through. Besides this normal difficulty, accessory canals, additional canals, severely curved canals and abnormal anatomy like additional roots etc make root canal treatment far more complicated.
Complex root canal system is one of the reasons for root canal treatment failure. The more complicated the root canal system is, the more difficult to clean it thoroughly and higher chance to have a failure.
This case showed how a simple and straight root canal became complicated. Top front teeth normally have single and straight root canals and can be the easiest root canal treatments. What made this root canal system complicated were two accessory or lateral canals. They were impossible to be physically cleaned by endodontic files. But with thorough chemical irrigation, ultrasonic cleaning and firm root canal filling (obturation), they were cleaned and filled successfully. If they were left untreated, it's likely to have persist infection and eventually failed.
This is another case showing the complexity of root canal system. The main root canal divided into multiple accessory canals near the root apex. It's called apical delta or apical ramifications. Proper technique and skills were required to fill these thoroughly and achieve high success rate.
Another case with lateral canal.