Root canal therapy removes inflamed or infected pulp from inside a tooth, cleans and disinfects the root canal system, and seals it. The pulp is the soft tissue in the centre of the tooth that holds nerves and blood vessels. Treatment is usually recommended when deep decay, a crack, an injury, or infection has damaged the pulp, and its aim is to save a tooth that might otherwise need to come out. Not every toothache means you need a root canal, and no treatment can guarantee a tooth will last forever. This guide explains when treatment is needed, what happens, and what recovery is usually like.
When Is Root Canal Therapy Necessary?
Root canal therapy is needed when the pulp is irreversibly inflamed or infected but the tooth itself can still be restored. A dentist must examine the tooth and take X-rays before recommending it.
Common causes include:
• Deep decay that reaches the pulp
• Cracked or fractured teeth that expose or damage the pulp
• Dental trauma. The American Association of Endodontists notes that trauma can damage the pulp even without visible cracks, and problems may appear months later.
• Repeated dental work on the same tooth
• An abscess, a pocket of infection near the root tip
Root canal therapy may not be suitable when too little healthy tooth remains, the tooth has an untreatable fracture, or gum and bone support is poor. Not every infected tooth can be saved.
What Are the Signs You May Need a Root Canal?
Common signs include ongoing tooth pain, sensitivity to hot or cold that lingers, pain when biting, swollen gums, a darkening tooth, and a pimple-like bump on the gum. Some teeth that need treatment cause no symptoms and are found on an X-ray.
| Possible sign | What you may notice | What to do |
| Persistent toothache | Ongoing or recurring pain | Book a dental examination |
| Lingering sensitivity | Pain that continues after hot or cold | Have the tooth assessed |
| Pain when chewing | Discomfort when biting down | Have the tooth checked |
| Gum swelling | Swollen or tender gum near a tooth | Contact a dentist promptly |
| Discolouration | A tooth turning grey or darker | Discuss with your dentist |
| Gum bump or drainage | A pimple-like swelling that may leak | Seek prompt dental care |
These signs can have other causes. For urgent problems, see our Emergency Dentistry page. Facial swelling that spreads quickly, or trouble swallowing or breathing, needs emergency medical care: call 911 or go to the nearest emergency department.
Root Canal Treatment Explained: What Happens Step by Step?
A root canal procedure involves numbing the tooth, removing the damaged pulp, cleaning and shaping the canals, filling and sealing them, and restoring the tooth.
1. Examination and diagnosis, including tests and X-rays.
2. Local anesthetic to numb the area. Tell your dentist if you feel pain at any stage.
3. Isolation with a dental dam, a thin rubber sheet that keeps the tooth clean and dry.
4. Access through a small opening to reach the pulp.
5. Removal of the inflamed or infected pulp.
6. Cleaning and shaping of the canals.
7. Filling and sealing with a rubber-like material called gutta-percha.
8. Restoration with a filling or crown, sometimes after a temporary filling.
9. Follow up to check healing.
The Canadian Dental Association notes that treatment may take one or two appointments, depending on the tooth and any infection. Learn more about our Root Canal Therapy in Thunder Bay service.
Is Root Canal Therapy Painful?
Root canal therapy is not usually painful during treatment because local anesthetic numbs the tooth. Most people feel pressure rather than sharp pain. The American Association of Endodontists explains that root canals usually relieve pain rather than cause it, since the inflamed pulp is often the source of the pain.
Mild tenderness when biting is common for a few days afterward. Your dentist may suggest suitable over-the-counter pain relief. Severe, worsening, or long-lasting pain should be checked. If you feel anxious about treatment, our guide to managing dental anxiety may help.
How Long Does Recovery Take?
Most people feel better within a few days. The American Association of Endodontists says symptoms usually improve within three to five days. Healing around the root, especially after a bad infection, can continue for weeks or months.
| Recovery period | What you may experience |
| First 24 hours | Numbness, then mild tenderness |
| Days 1 to 3 | Possible sensitivity when chewing |
| Days 4 to 7 | Symptoms usually easing |
| Following weeks and months | Continued healing around the root, where infection was present |
Recovery depends on the original infection, the tooth’s root shape, how complex treatment was, and how soon the final restoration is placed. Many people return to their usual activities soon after treatment, but ask your dentist what to expect in your case.
How Should You Care for the Tooth Afterward?
• Avoid chewing until the numbness wears off.
• Go easy on the tooth while it has a temporary filling or is waiting for a crown.
• Take any recommended medication exactly as directed. Antibiotics are not needed after every root canal.
• Keep brushing with fluoride toothpaste and cleaning between your teeth.
• Get the final restoration placed as advised, since delay raises the risk of fracture or reinfection.
• Attend follow-up visits.
Contact your dentist if you notice severe or worsening pain, swelling that persists or increases, fever, a loose or lost temporary filling, or symptoms that return after improving.
Root Canal Therapy vs. Tooth Extraction
| Comparison | Root canal therapy | Tooth extraction |
| Purpose | Treat the canals and keep the natural tooth | Remove the affected tooth |
| When used | Inflamed or infected pulp in a restorable tooth | Tooth cannot be predictably saved |
| Natural tooth | Kept | Removed |
| Afterward | Usually needs a filling or crown | May need an implant, bridge, or denture |
The Canadian Dental Association notes that keeping a natural tooth helps stop neighbouring teeth drifting out of line. When comparing costs, include the full path: root canal therapy plus a crown, or extraction plus a possible dental implant in Thunder Bay, bridge, or denture. Neither option is always better.
How Long Does a Root Canal-Treated Tooth Last?
A treated tooth can last many years. How long depends on the quality of treatment, the final restoration, how much healthy tooth remains, gum and bone health, oral hygiene, bite forces or grinding, and regular check-ups. Root canal treatment can sometimes fail and need retreatment or extraction.
Who Provides Root Canal Therapy?
General dentists carry out many root canal treatments. Endodontists are specialists in the pulp and the tissues around tooth roots, and complex cases may be referred to them. Read more about when you may need a root canal specialist. At Redwood Dental Centre, root canal therapy is provided by our general dentist, with referral to a specialist when a case calls for it.
What Happens If You Delay Root Canal Treatment?
Waiting rarely makes an inflamed or infected pulp heal on its own. Pain may come and go, and a tooth that stops hurting can still have an active infection, because the nerve inside may have died. Delaying treatment can allow infection to spread into the bone around the root, form an abscess, or weaken the tooth further, which can reduce the chance of saving it.
If cost or timing is a concern, tell your dentist. They can explain which steps are urgent, whether a temporary measure such as opening and medicating the tooth makes sense, and how treatment might be phased.
What Is the Pulp and Why Does It Matter?
The pulp is the living tissue in the centre of the tooth. It contains nerves, blood vessels, and connective tissue, and runs from the crown of the tooth down through narrow channels called root canals to the tip of each root.
The pulp helps a tooth develop while it is growing. Once a tooth is fully formed, it can survive without the pulp because the surrounding gum, bone, and ligament keep supplying it. That is why removing damaged pulp and sealing the canals can keep a tooth working for years.
| Tooth layer | What it is | Role |
| Enamel | Hard outer layer of the crown | Protects the tooth from wear and bacteria |
| Dentine | Layer beneath the enamel | Supports the enamel; transmits sensation |
| Pulp | Soft tissue in the centre | Contains nerves and blood vessels |
| Root canals | Channels inside each root | Hold the pulp running to the root tip |
Can a Root Canal Fail, and What Happens Next?
Most root canal-treated teeth heal well, but treatment can sometimes fail. Common reasons include a canal that was hard to find or clean, a crack in the root, new decay, or a filling or crown that leaks and lets bacteria back in. Signs include pain or swelling that returns, a gum bump, or changes on a follow-up X-ray.
Options depend on the cause:
• Retreatment: the tooth is reopened, the filling material removed, and the canals cleaned and sealed again.
• Root-end surgery (apicoectomy): a specialist removes the tip of the root and seals it from the outside.
• Extraction: when the tooth cannot be predictably saved, followed by planning for a replacement.
Your dentist may refer you to an endodontist for retreatment or surgery.
What Can You Eat After a Root Canal?
Wait until the numbness wears off before eating so you do not bite your cheek, tongue, or lip. For the first few days, soft foods such as eggs, yogurt, soup that has cooled, pasta, and cooked vegetables are easiest. Chew on the other side, and avoid hard, sticky, or very chewy foods on the treated tooth until the final filling or crown is in place.
Does Insurance Cover Root Canal Therapy?
Many dental plans include some coverage for root canal therapy, but the amount depends on your plan, waiting periods, annual maximums, and whether the tooth also needs a crown. Ask for a treatment estimate that lists the root canal and the final restoration separately, and submit it to your insurer before treatment if you are unsure what will be covered. If you are enrolled in the Canadian Dental Care Plan, ask whether the services you need are eligible and whether a co-payment applies.
Are Front and Back Teeth Treated Differently?
Front teeth usually have one canal and are reached through the back of the tooth, while molars can have three or more canals that curve or branch, which can make treatment longer. Back teeth also take heavier chewing forces, which is why they more often need a crown afterward. Your dentist will explain what applies to your tooth.
Root Canal Therapy and Pregnancy
If you are pregnant and have a painful or infected tooth, tell your dentist. Urgent dental care is often still recommended, with planning around X-rays and medications. Your dentist may consult your doctor or midwife.
Frequently Asked Questions
What is root canal therapy and why is it needed?
It removes inflamed or infected pulp, cleans and disinfects the canals, and seals them. It may be needed when deep decay, cracks, injury, or infection damage the pulp, and the goal is to save a tooth that can still be restored.
Is root canal treatment painful?
Not usually. Local anesthetic numbs the area, so most people feel pressure rather than pain. Mild tenderness when chewing is common for a few days afterward.
How long does a root canal procedure take?
It depends on the tooth, the number and shape of its canals, and any infection. Some treatments are done in one appointment; others need two or more.
How long does it take to recover from a root canal?
Most people feel less tender within a few days. Healing around the root can continue for weeks or months. Contact your dentist if symptoms get worse.
Will I need a crown after root canal treatment?
Many treated teeth need a crown, especially back teeth that take heavy chewing forces. Your dentist will recommend a restoration based on the tooth and your bite. Learn more about our Crowns and Bridges in Thunder Bay service and whether dental crowns are covered by insurance.
Book an Assessment in Thunder Bay
If you have tooth pain, swelling, or signs of infection, contact Redwood Dental Centre to book an examination. We will find the cause and explain your options, including root canal therapy, the final restoration, and alternatives. Looking for a dentist in Thunder Bay? Redwood Dental Centre welcomes new patients.
*This article is general information, not dental advice for your situation.*