Root Canal Therapy: What Happens, Step by Step
Root canals have a reputation problem, and most of what’s written to counter it is as unreliable as the reputation itself.
You’ll find a “95% success rate” repeated across hundreds of dental websites, usually credited to the American Association of Endodontists. The AAE’s own patient materials state no such figure; they describe root canal treatment as having a high success rate without attaching a number. The percentage appears to come from studies measuring tooth survival — whether the tooth is still in your mouth — which is a different question from whether treatment succeeded radiographically.
A root canal removes infected pulp from inside a tooth, disinfects and shapes the canals, and seals them, so the tooth can stay in place. It takes one or two appointments of 60 to 90 minutes and feels much like having a filling, because the tooth is fully anesthetized. The permanent restoration placed afterward is what determines how long it lasts.
What is a root canal?
Inside every tooth is a soft core of nerve and blood vessels called the pulp. When decay, a crack, or trauma lets bacteria reach it, the pulp becomes inflamed or infected. It can’t heal on its own, and the infection spreads toward the bone at the root tip.
Root canal therapy removes that infected tissue, disinfects and shapes the canals, and seals them. The tooth stays in place. What’s removed is the pulp, not the tooth.
What are the signs you need a root canal?
- A severe or lingering toothache
- Sensitivity to hot or cold that persists after the stimulus is gone
- Swelling, or a pimple-like bump on the gum near the tooth
- A tooth that’s darkening or discolouring
- Pain on biting or chewing
Worth knowing: not every tooth that needs a root canal hurts. Pulp can die quietly, and the problem shows up on a routine x-ray with no symptoms at all. Pain is a reliable signal when it’s present and an unreliable one when it’s absent.
What happens during a root canal, step by step?
- Diagnosis. Radiographs confirm the infection and pulp testing establishes whether the nerve is alive, dying, or dead.
- Anesthesia and isolation. Local anesthetic numbs the tooth, and a thin rubber dam isolates it — keeping the area dry and stopping anything reaching the back of your throat.
- Access. A small opening is made through the top of the tooth.
- Cleaning and shaping. The pulp is removed and the canals are disinfected and shaped with fine instruments.
- Filling and sealing. The cleaned canals are filled with gutta-percha, a biocompatible material, and sealed.
- Temporary filling. This protects the tooth between appointments.
- Final restoration. A permanent filling or crown is placed at a follow-up visit.
Most root canals take 60 to 90 minutes per visit and need one or two appointments. Because the tooth is fully anesthetized, the procedure itself feels much like having a filling done. The rubber dam is the part patients report as most unfamiliar, and it’s also the part that makes the treatment work — canals have to stay free of saliva.
What is recovery from a root canal like?
Most people are back to normal within a few days. Soreness peaks in the first day or two and responds well to over-the-counter ibuprofen or acetaminophen.
For the first while:
- Avoid chewing on the treated tooth until the permanent restoration is in place. The temporary filling is soft by design.
- Stick to softer foods for a few days, and steer clear of ice, nuts, and hard candy.
- Brush and floss normally, gently around the treated tooth.
- Warm salt-water rinses — about half a teaspoon in a cup of warm water — help with tenderness.
- Don’t smoke. It slows healing meaningfully.
Call the office if pain is severe, worsening after the first couple of days, or accompanied by swelling. That’s not typical and it’s worth checking.
Seek urgent care the same day for facial or neck swelling, fever, or any difficulty swallowing or breathing. A dental infection that spreads is uncommon but serious — if you can’t reach us, go to an emergency department.
Why does the final restoration matter so much?
This is the part that gets skipped, and it matters more than anything else on this page.
The largest study of its kind followed 71,283 root-canal-treated teeth across 99 general practices. Teeth that received a filling soon after treatment and then a crown had a median survival of 20.1 years. Teeth left with no filling and no crown: 6.5 years.
| Restoration after the root canal | Median survival of the tooth |
|---|---|
| A filling soon after, then a crown | 20.1 years |
| Crown only | 11.4 years |
| Filling only | 11.2 years |
| Neither | 6.5 years |
A crown alone came in at 11.4 years, a filling alone at 11.2. So the benefit isn’t the crown by itself — it’s the sequence of sealing the tooth promptly and then protecting it properly. Overall median survival across all teeth in that study was 11.1 years, pulled down by the large share that were never properly restored.
That’s observational data, so some caution is warranted: teeth that never get restored may be a harder-to-restore group to begin with, and insurance status was itself a predictor of who completed treatment. But the size of the gap is hard to argue with.
The practical takeaway is simple. A root canal is not finished when you walk out after the last canal appointment. It’s finished when the tooth is permanently restored, ideally within about a month. Waiting longer risks fracture and new decay through the temporary.
How long do treated teeth last?
Depends which question you’re asking, and the distinction is worth understanding.
Survival — the tooth is still in your mouth. A study of nearly 1.5 million treated teeth found 97% still in service at eight years. A long-term series in a single specialist practice followed teeth for up to 37 years and found 97% survival at 10 years and 81% at 20. That series comes from one endodontist’s private practice and required patients to attend annual recalls, so it sits above what a general population would show — but it establishes what’s achievable.
Success — the infection resolved and the bone healed on radiographs. A 2022 systematic review of 42 studies put pooled success at 82% under strict criteria and 92.6% under looser ones.
| Measure | What it tells you | Figure |
|---|---|---|
| Survival | Whether the tooth is still in your mouth | 97% at 8 years; 81% at 20 years |
| Success | Whether the infection resolved and the bone healed on radiographs | 82% pooled under strict criteria, 92.6% under looser ones |
Both numbers describe good treatment. Success is the stricter standard and the lower figure; survival is what most patients actually care about and the higher one. A single number quoted without saying which one it is doesn’t tell you much.
Does insurance cover a root canal?
Most plans split a root canal across two categories. The therapy itself is usually a basic service, often reimbursed at 70–80%, though some plans place endodontics in its own category at a lower rate. The crown that follows is usually a major service at around 50%, drawn against the same annual maximum — which commonly sits between $1,000 and $2,500 and can be exhausted by a single tooth.
Under the Canada Dental Care Plan, standard root canals on front teeth, bicuspids, and first and second molars are covered without preauthorization. Retreatments, apicoectomies, and root canals on third molars require approval first, as do crowns.
Root canal therapy is one of the services we provide at Mellow Family Dental Care, and we direct-bill all insurance companies. For a treatment plan that includes a crown, ask us to submit a predetermination so your share is confirmed before anything starts.
Common questions
Is a root canal painful? Not during the procedure — the tooth is fully anesthetized and it feels much like a filling. Afterwards, expect mild soreness for a day or two, manageable with over-the-counter pain relief. The infection that leads to a root canal is usually far more painful than the treatment.
Do I always need a crown afterward? Molars and heavily restored teeth almost always do; they carry the most force and become brittle once the pulp is gone. Some intact front teeth need only a filling. The restoration data above is the reason this isn’t treated as optional.
Can it be done in one visit? Simple cases often can. Molars with curved or numerous canals more often take two.
What if I put it off? The infection spreads into the surrounding bone. That leads to more complex treatment, and eventually to the tooth becoming unsalvageable.
Does the tooth stay alive? No. The pulp is removed, so the tooth no longer has a nerve or blood supply. It remains fully functional, held in place by the ligament and bone around the root, but it won’t respond to temperature and it becomes more brittle over time.
What’s a retreatment? Redoing a root canal on a tooth that was treated before and has reinfected. It’s more involved than the original because the previous filling material has to be removed first, and it requires preauthorization under the CDCP.
Related reading
Toothache, swelling, or a tooth you’ve been told needs a root canal? Call Mellow Family Dental Care at 604.457.2273, or visit us at Unit 150–20528 Lougheed Highway in West Maple Ridge. We see emergency dental problems.
Sources: Thyvalikakath T, et al. Root Canal Treatment Survival Analysis in National Dental PBRN Practices. Journal of Dental Research 2022;101(11):1328–1334. Link · Burns LE, et al. Outcomes of primary root canal therapy: An updated systematic review. International Endodontic Journal 2022;55(7):714–731. Link · Salehrabi R, Rotstein I. Endodontic treatment outcomes in a large patient population in the USA. Journal of Endodontics 2004. Link · López-Valverde I, et al. Clinical Oral Investigations 2023;27(6):3233–3244. Link
This article is general information and does not replace an in-person dental exam.
