Canines and incisors. Canine and incisor teeth are the teeth in the front of your mouth that help you tear and cut food when you eat. Their single root makes them faster and easier to fill and treat.
Premolars. Premolars are more toward the middle of your teeth. They have one or two roots, so cleaning them out may take an hour or more.
Molars. Molars are the large teeth in the back of your mouth and can have up to four canals. Root canals performed on molars can take 90 minutes or more.