Root canal therapy is a dental procedure that removes inflamed or infected pulp from inside a tooth, cleans and disinfects the root canal system, and then seals the space. The pulp is the soft tissue in the centre of the tooth that contains nerves and blood vessels.
Treatment is usually recommended when the pulp is badly inflamed, infected or damaged, often because of deep decay, a crack, an injury or an infection. The aim of a root canal procedure is to save a natural tooth that might otherwise need to be removed.
The signs you need a root canal are not always obvious. Some teeth cause strong pain, while others cause few symptoms at all. Not every toothache means you need a root canal, and treatment cannot guarantee that a tooth will last forever. If you have tooth pain that will not settle, swelling or other worrying symptoms, book a dental assessment. This guide from Redwood Dental Centre in Thunder Bay covers when treatment is needed, what happens during it and what root canal recovery is usually like.
When Is Root Canal Therapy Necessary?
Root canal therapy is necessary when the pulp inside a tooth 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.
Deep tooth decay
When decay reaches the pulp, bacteria can cause inflammation or infection. If the pulp cannot recover, root canal therapy may be needed to save the tooth.
Infected dental pulp
Bacteria can reach the pulp through deep cavities, cracks or other damage. Infection can then spread to the tissues around the root tip.
Cracked or fractured teeth
Some cracks expose or damage the pulp. Where the crack is and how deep it goes decide whether treatment is possible.
Dental trauma
A knock to a tooth can damage the pulp even if the tooth looks fine. The American Association of Endodontists notes that trauma can damage the pulp even without visible cracks. Problems may only show up months later.
Repeated dental procedures
Several large fillings or repeated work on the same tooth can sometimes irritate the pulp.
Dental abscesses
An infection that starts inside the tooth can form an abscess (a pocket of pus) near the root. Treatment may involve root canal therapy, draining the infection, removing the tooth or other care, based on the diagnosis.
When a root canal may not be suitable
Root canal treatment may not be the right option if:
- Too little healthy tooth structure remains to restore it.
- The tooth has a fracture that cannot be treated.
- Gum and bone support around the tooth is poor.
- Other factors make the long-term outlook unlikely to be good.
Not every infected or badly damaged tooth can be saved.
What Are the Common Signs You May Need a Root Canal?
Common signs you need a root canal 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 at all.
Persistent tooth pain
Pain may be constant, come and go, or be triggered by eating or lying down.
Lingering sensitivity to hot or cold
Discomfort that lasts after the hot or cold food or drink is gone can point to an inflamed pulp. Brief sensitivity has many other causes, such as exposed roots.
Pain when biting or chewing
Tenderness when you bite down can come from problems in the pulp or around the root.
Swollen or tender gums
Swelling near a tooth can be a sign of infection.
Tooth discolouration
A tooth may turn grey or darker after an injury or pulp damage. Colour change alone does not confirm infection.
A pimple-like bump on the gum
A small bump that may leak fluid can be a draining infection.
Cracked or damaged teeth
Visible cracks, chips or deep cavities raise the chance that the pulp is involved.
Problems without pain
A tooth with a dead pulp or an infection can sometimes cause little or no pain. These are often found during a check-up or on an X-ray.
| Potential Symptom | What Patients May Notice | Recommended Action |
| Persistent toothache | Ongoing or recurring tooth pain | Arrange a dental examination |
| Lingering temperature sensitivity | Pain continuing after hot or cold exposure | Seek professional assessment |
| Pain when chewing | Discomfort when biting down | Have the tooth checked |
| Gum swelling | Swollen or tender tissue near a tooth | Contact a dentist promptly |
| Tooth discolouration | A tooth becoming noticeably darker | Discuss with a dental professional |
| Gum bump or drainage | Pimple-like swelling or discharge | Seek prompt dental care |
These symptoms can also come from other dental problems. Only a dental examination can confirm whether you need root canal therapy. For urgent dental problems, see our Emergency Dentistry page. Facial swelling that spreads quickly, or difficulty swallowing or breathing, needs urgent medical care: call 911 or go to the nearest emergency department.
What Happens During a Root Canal Procedure?
A root canal procedure involves numbing the tooth, removing the damaged pulp, cleaning and shaping the canals, filling and sealing them, and then restoring the tooth. Treatment may take one or two appointments.
- Examination and diagnosis: Your dentist checks the tooth, asks about your symptoms and may run simple tests and take X-rays.
- Local anesthetic: The area is numbed. Tell your dentist if you feel pain at any stage.
- Isolating the tooth: A thin rubber sheet called a dental dam is placed around the tooth to keep it dry and clean.
- Opening the tooth: A small opening is made to reach the pulp chamber and root canals.
- Removing the pulp: Fine instruments remove the inflamed or infected tissue.
- Cleaning and shaping: The canals are cleaned, disinfected and shaped so they can be filled.
- Filling and sealing: The canals are filled with a rubber-like material called gutta-percha and sealed.
- Restoring the tooth: The tooth needs a filling or crown to protect it and restore function. Sometimes a temporary filling is placed first.
- Follow-up: Your dentist may recommend check-ups or X-rays to confirm healing.
Some root canals can be finished in one visit. Others need two or more, based on the tooth’s anatomy, the infection and the complexity of the case. The Canadian Dental Association notes that treatment may take one or two appointments. Learn more about our Root Canal Therapy 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 or movement rather than sharp pain.
Pain control during treatment
The American Association of Endodontists explains that modern root canals usually relieve pain rather than cause it. Tell your dentist right away if you feel discomfort, so they can give more anesthetic.
Why the tooth may hurt before treatment
An inflamed or infected pulp is often what causes the pain that leads people to the dentist. Treatment removes the source of that pain.
Discomfort after treatment
Mild tenderness or soreness when biting is common for a few days afterward.
Managing discomfort
Your dentist may suggest suitable over-the-counter pain relief and a cold compress. Follow their advice and the product directions.
When pain needs checking
Severe, worsening or long-lasting pain should be assessed by your dentist. Everyone’s experience is different. If you feel anxious about treatment, our guide to managing dental anxiety may help.
How Long Does It Take to Recover From Root Canal Therapy?
Most people feel better within a few days of root canal therapy and can return to normal activities quickly. Healing around the root, especially after a bad infection, can continue for weeks or months.
| Recovery Period | What Patients May Experience |
| First 24 hours | Temporary numbness and mild tenderness |
| Days 1 to 3 | Possible sensitivity or discomfort when chewing |
| Days 4 to 7 | Symptoms often continue to improve |
| Following weeks | Further recovery of the surrounding tissues |
| Following months | Ongoing healing of infection-related changes when present |
First 24 hours
Numbness can last a few hours. Mild tenderness may start as the anesthetic wears off.
Days 1 to 3
Some sensitivity when chewing is common. Symptoms should start to improve.
Days 4 to 7
Tenderness usually eases. The American Association of Endodontists says symptoms usually improve within three to five days.
Weeks and months afterward
If there was an infection around the root, the bone and tissue there may take months to heal. Follow-up X-rays can show how healing is progressing.
Factors that affect root canal recovery
- How severe the infection was before treatment.
- The tooth’s position and root shape.
- How complex the procedure was.
- Inflammation around the root.
- Your own healing response.
- How well and how soon the final restoration is placed.
- Any complications.
These timeframes are a guide, not a guarantee. Contact your dentist if pain, swelling or other symptoms get worse.
How Can You Care for Your Tooth After Root Canal Treatment?
After root canal treatment, avoid chewing until the numbness wears off, go easy on the treated tooth, keep it clean and get the final restoration placed as advised.
Avoid chewing while numb
You could bite your tongue, cheek or lip without realizing.
Protect the treated tooth
Avoid hard or sticky foods on that side while the tooth has a temporary filling or is waiting for a crown.
Follow medication advice
Take any recommended or prescribed medication exactly as directed. Antibiotics are not needed after every root canal.
Keep up good oral hygiene
Keep brushing with fluoride toothpaste and cleaning between your teeth, gently around any tender spots.
Complete the final restoration
A permanent filling or crown protects the tooth from breaking and from bacteria getting back in. Delaying it can raise the risk of fracture or reinfection.
Attend follow-up visits
Check-ups let your dentist review symptoms, the restoration and healing.
Contact your dentist if you notice:
- Severe or worsening pain.
- Swelling that persists or increases.
- Fever.
- A temporary filling or crown that loosens or falls out.
- Significant pain when biting.
- Symptoms that return after improving.
Your dentist’s instructions come first.
Root Canal Therapy vs. Tooth Extraction
Root canal therapy keeps your natural tooth, while an extraction removes it. The right choice comes down to whether the tooth can be saved and restored.
| Comparison | Root Canal Therapy | Tooth Extraction |
| Primary purpose | Treat the root canal system and keep the natural tooth | Remove the affected tooth |
| Common indications | Irreversible pulp inflammation or infection in a restorable tooth | Tooth cannot be predictably saved, or removal is otherwise advised |
| Treatment approach | Remove damaged pulp, disinfect canals and seal the tooth | Remove the tooth from its socket |
| Natural tooth | Kept | Removed |
| Restoration needs | Often needs a permanent filling or crown | May need tooth replacement planning |
| Recovery | Usually brief tenderness | Healing of the extraction socket |
| Long-term considerations | Needs a restoration, good hygiene and monitoring | May need an implant, bridge or denture |
Benefits of keeping a natural tooth
Saving a restorable tooth helps you keep chewing normally. The Canadian Dental Association notes that keeping the tooth also helps stop neighbouring teeth drifting out of line.
When extraction may be better
Extraction may be advised for a tooth with an untreatable fracture, severe damage, weak gum and bone support or a poor long-term outlook.
Costs and long-term care
Compare the total cost of each path: root canal therapy plus a crown, or extraction plus a possible replacement such as a dental implant, bridge or denture.
Making an informed decision
Ask your dentist about the tooth’s outlook, your options, the risks and what each choice needs long term. Neither option is always better.
How Long Does a Root Canal-Treated Tooth Last?
A tooth treated with root canal therapy can last many years. The treatment, the final restoration and how well you look after it all affect how long.
- Quality of treatment: thorough cleaning, disinfection and sealing all matter.
- The final restoration: a well-fitting filling or crown protects against fracture and leakage.
- Remaining tooth structure: more healthy tooth means a better outlook.
- Gum and bone health: strong support helps keep the tooth.
- Oral hygiene: a treated tooth can still decay or develop gum problems.
- Bite forces and grinding: heavy forces can crack treated teeth.
- Regular check-ups: your dentist can spot problems early.
Root canal treatment can sometimes fail and may need retreatment, further procedures or extraction. No treated tooth is guaranteed to last a lifetime.
Choosing a Dentist for Root Canal Therapy
Choose a qualified dentist who diagnoses carefully, explains your options and plans the final restoration from the start.
Look for:
- Appropriate dental qualifications and registration with the Royal College of Dental Surgeons of Ontario.
- Experience diagnosing and treating pulp problems.
- Access to the right examinations and X-rays.
- Clear explanations of root canal therapy and alternatives.
- Honest discussion of risks and limitations.
- Good infection control, including use of a dental dam.
- A plan for the final restoration.
- Clear information about costs and appointments.
- A process for follow-up if symptoms persist.
- Referral to a specialist for complex cases when needed.
General dentists carry out many root canal treatments. Endodontists are specialists who focus on the pulp and the tissues around tooth roots, and complex cases may be referred to them. Our article explains when you may need a root canal specialist. Ask whether your case can be treated at the practice or needs a referral.
Root Canal Therapy in Thunder Bay
A professional dental assessment is the first step if you have tooth pain, swelling or signs of infection. Your dentist can examine the tooth, check the health of the pulp, review X-rays and decide whether root canal therapy or another treatment is right for you.
If you are looking for a dentist in Thunder Bay, Redwood Dental Centre offers Root Canal Therapy, provided by our general dentist. Most discomfort after treatment improves within a few days, and many of our patients return to school or work the next day. Treated back teeth often need a crown afterward, so we can plan that with you. Learn more about our Crowns and Bridges service and whether dental crowns are covered by insurance.
Call us to confirm treatment availability, appointment times, costs and specialist referral options.
Frequently Asked Questions
What is root canal therapy and why is it needed?
Root canal therapy removes inflamed or infected pulp from inside a tooth, cleans and disinfects the root canals and seals them. It may be needed when deep decay, cracks, injury or infection damage the pulp. The goal is to save a tooth that can still be restored.
Is root canal treatment painful?
Root canal treatment is not usually painful, because local anesthetic numbs the area. You may feel pressure or movement, so tell your dentist if you feel pain. Mild tenderness, especially when chewing, is common for a few days afterward.
How long does a root canal procedure take?
The tooth, how many canals it has, its shape, any infection and how complex the case is all affect the time. Some treatments are done in one appointment of an hour or more, while others need longer or several visits. Ask your dentist for an estimate.
How long does it take to recover from a root canal?
Most people feel less tender within a few days. Some sensitivity can last longer, depending on the original infection and how complex treatment was. 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 root canal-treated teeth need a crown, especially back teeth that take heavy chewing forces. Not every treated tooth needs one. Your dentist will recommend a restoration based on the tooth’s position, how much of it remains and your bite.
Saving Your Natural Tooth
Root canal therapy can save a tooth with an inflamed or infected pulp, as long as the tooth can still be restored. Getting an accurate diagnosis early, completing the final restoration and keeping up good daily care all improve the outlook for the tooth.
Dealing with tooth pain or swelling? Book an examination so we can find the cause and explain your options, including the procedure, recovery, final restoration and alternatives. Contact us to ask about root canal therapy and appointment availability.
This article is general information, not dental advice for your situation. Speak with a dentist about your own symptoms and treatment options.