How Long Does a Root Canal Take? Time per Tooth and Number of Visits

The Short Answer

Most root canals take 45 to 90 minutes per visit, and many are finished in one visit. A difficult tooth can take close to two hours, or be split across two visits so the infection can settle first.

How Long Each Type of Tooth Usually Takes

This is a rough guide. Your X-ray and your tooth decide the real time.

• Front teeth (usually one canal): about 45 to 60 minutes.
• Premolars (one or two canals): about 45 to 75 minutes.
• Molars, the large back teeth (three or four canals, sometimes more): about 60 to 90 minutes.
• Redoing an old root canal (retreatment): often longer, and often two visits.

Can a Root Canal Take 2 Hours?

Yes, and it doesn't mean something has gone wrong. These are the usual reasons:

• Curved or very narrow canals: they take longer to clean safely.
• An extra canal or extra root: some teeth have more than expected, and each one must be treated.
• An old root canal being redone: the old filling has to come out first.
• A broken instrument inside the canal: working around it takes patience.
• A very painful tooth: an inflamed lower molar can take longer to numb properly.

You can ask for a short break at any time. If the appointment is getting long, it can also be stopped safely and finished at a second visit.

One Visit or Two?

One visit usually works when the infection is limited, there is no pus draining into the canal, and the canals can be cleaned and dried in one sitting.

Two visits are usually better when:

• The face or gum is swollen, or pus keeps draining into the tooth
• The canals can't be dried properly at the first visit
• The tooth needs a medicine left inside it for a week or two
• The case is too long to finish comfortably in one sitting

Between visits the tooth has a temporary filling, so avoid chewing hard food on that side. A Cochrane research review, updated in 2022, found no clear difference in how well teeth heal after one visit compared with several, although pain in the first week was more likely after a single visit. The right number of visits is whatever lets the canals be cleaned and sealed properly.

What Happens During That Time

1. Numbing: the tooth is numbed and given time to take effect.
2. Opening the tooth: a small opening gives access to the canals.
3. Measuring: each canal's length is measured with an electronic apex locator and X-rays.
4. Cleaning and shaping: the infected nerve is removed and the canals are shaped with rotary instruments, under magnification.
5. Disinfecting: the canals are washed with disinfecting solutions.
6. Sealing: the canals are filled and sealed, and an X-ray checks the result.
7. Closing the tooth: a filling closes the opening.

The Crown Is a Separate Step

The time above covers the root canal only. Most back teeth also need a crown (cap) to protect them from breaking, ideally within a few weeks. Read more in do you need a crown after a root canal.

After the Appointment

• The numbness usually wears off within a few hours.
• Most people go back to work the same day.
• Mild soreness when biting is common for a few days. See what pain is normal after a root canal.

Bottom Line

Plan for 45 to 90 minutes, and expect a difficult tooth to take longer or need a second visit. The time matters far less than whether every canal is properly cleaned and sealed.

To find out what your tooth needs, read how root canal treatment works, or call or WhatsApp +91 97370 97666. I see patients across Ahmedabad by appointment, and emergency calls are answered 24/7, in English, Hindi or Gujarati.

Dr. Bhavya Soni
BDS | MDS, Conservative Dentist & Endodontist