The length of a root canal procedure varies based on the number of canals that the tooth has and the complexity of its root canal system. Most procedures can be completed in a single visit, ranging from 40 minutes for a single rooted front tooth, to 2 hours for a molar with 4 or more canals. If a tooth is severely infected, it may be beneficial to access the root canal system and place medicament for disinfection during the first visit, and then return for a second appointment to finish cleaning and filling the root canals.