Root canal: what actually happens, step by step
A root canal removes infected or damaged tissue inside your tooth. Learn what to expect during the procedure, from numbing through sealing and aftercare.
Medically reviewed by Dr. Jose, DDS — July 7, 2026
Why a root canal is done
A root canal becomes necessary when the inner tissue of your tooth — the pulp — is infected, inflamed, or damaged. This can happen due to deep decay, repeated dental work, cracks, chips, or trauma. If left untreated, the infection can spread and eventually lead to tooth loss or more serious complications.
What to expect: the step-by-step process
Before the procedure
Your dentist will take X-rays to see inside the tooth and confirm the problem. You’ll discuss what to expect and have a chance to ask questions. If you have anxiety about dental procedures, tell your dentist — they can work with you to make the experience more comfortable.
Numbing and access
Your tooth and the area around it will be numbed with a local anesthetic. You may also be offered nitrous oxide (“laughing gas”) or other comfort options, depending on your dentist’s practice. Once numb, you should feel pressure and vibration but not pain.
Your dentist will place a rubber dam — a small latex or non-latex sheet — around the tooth to keep it dry and isolate it from saliva. This is a standard safety step.
Removing the infected tissue
The dentist will create a small opening in the crown (top) of the tooth to access the pulp chamber. Using special instruments, they carefully remove the infected or inflamed pulp tissue from inside the tooth and from the canals that run through the root. This part of the procedure is the “cleaning” phase.
Shaping and cleaning the canals
Once the pulp is removed, the inside of the tooth is cleaned, shaped, and disinfected. This prepares the canals for filling. Your dentist may use an electronic device to help measure the length of the canals to ensure thorough cleaning.
Filling and sealing
The cleaned canals are filled with a biocompatible material (usually a rubber-like substance called gutta-percha) and a sealer cement. This prevents bacteria from re-entering and re-infecting the tooth. The access opening is then sealed with a filling material.
Restoration
After a root canal, your tooth is more fragile because it no longer has a living pulp to nourish it. Most teeth that have had root canals are restored with a crown, post-and-core build-up, or other permanent restoration. This protects the tooth and restores it to full function. Your dentist will recommend the best option for your tooth and discuss timing with you.
Aftercare and recovery
After the procedure, your tooth may feel slightly tender or sore for a few days. This is normal. Avoid chewing on the treated tooth until it is fully restored with a crown or other restoration. If you experience significant pain, swelling, or other concerns, contact your dentist promptly.
Most people return to normal activities right away. You can eat soft foods as soon as the numbing wears off.
When to call your dentist
Contact your dentist if you experience:
- Severe or worsening pain that doesn’t improve with over-the-counter pain relief
- Visible swelling of your face, jaw, or gums
- An allergic reaction (difficulty breathing, hives, swelling of lips or tongue)
- The tooth feeling taller or “hitting” when you bite
- A loose filling or crown on the treated tooth
- Symptoms that last more than a week
Understanding your options
If you’re worried about cost or recovery, have a conversation with your dentist about what’s involved and what happens if you delay treatment. You might also explore whether a second opinion makes sense for you. (Learn more about root canal alternatives and myths in our guide “Root canal myths vs. facts” and about comparing extraction to root canal in “Tooth extraction vs. root canal.”)
How MediMouth helps
If your dentist has recommended a root canal and you want to understand the procedure or explore your options, MediMouth dentists across Arizona can walk you through what to expect, answer your questions, and help you make an informed decision. Use our find-a-dentist tool to connect with a provider near you or request a second opinion.
Frequently asked questions
Will a root canal hurt?
Modern root canals are performed with numbing agents and focus on patient comfort. You should not feel pain during the procedure — though you may feel pressure or vibration. Some people experience discomfort afterward; ask your dentist what aftercare steps and over-the-counter options may help.
How long does a root canal take?
Most root canals take 30 minutes to two hours, depending on the tooth's location and complexity. Your dentist will give you a time estimate before you start.
Do I need a crown after a root canal?
Most teeth that have had a root canal benefit from a crown or other restoration to protect them and restore full function. Your dentist will advise you based on the tooth's condition and location. Ask about your options and timeline.