translate English to French: Problems with root canal treatments are caused by the dentist's inability to either completely clean out the inside of the tooth all the way to the apex, because of obstructions or curves, or an inability to completely seal the apex of the tooth, thus allowing leaking of living material into the tooth that can become a further source of infection. If this happens, it is called a failed root canal.
Le traitement endodontique est plus difficile avec les dents postérieures qu’avec les dents antérieures.