Why would you need a root canal?

Every tooth contains a soft tissue called the pulp, located in the centre of the tooth and extending down through channels (canals) in each root. The pulp contains nerves, blood vessels and connective tissue. It is essential during tooth development but once the tooth is fully formed, the tooth can survive without it.

A root canal becomes necessary when the pulp is damaged beyond repair. This happens because of:

• Deep tooth decay: Bacteria from an untreated cavity progress through the enamel and dentine layers until they reach the pulp, causing infection and inflammation
• Cracked or fractured tooth: A crack that extends into the pulp chamber allows bacteria to enter directly
• Trauma: A blow to a tooth (from a fall, sports injury or accident) can damage or sever the blood supply to the pulp, causing it to die even if the tooth appears intact externally
• Repeated dental procedures: A tooth that has undergone multiple fillings, crowns or other treatments can sustain cumulative irritation to the pulp, eventually triggering irreversible inflammation
• Large existing filling: A very deep filling sits close to the pulp and may eventually irritate or expose it

Signs you may need a root canal

• Severe, persistent toothache – especially throbbing pain that wakes you at night
• Prolonged sensitivity to hot or cold that lingers after the stimulus is removed (lasting more than 30 seconds)
• Darkening or discolouration of a tooth
• Swelling, tenderness or a persistent pimple on the gum near the tooth
• Pain when biting or pressing on the tooth

Sometimes a tooth needing root canal treatment causes no symptoms at all and is detected only on X-ray during a routine check-up. This is one reason regular dental visits are important.

The root canal procedure – step by step

Root canal treatment is typically completed in one or two appointments, depending on the tooth and whether active infection is present.

Step 1 – Diagnosis and treatment planning

Your dentist takes an X-ray to assess the shape of the root canals, the extent of infection, and the condition of the surrounding bone. Vitality tests (cold test, electric pulp test) may be performed to assess whether the nerve is alive, dying or dead. Based on these findings, your dentist confirms that root canal treatment is the appropriate option and explains the procedure, expected outcome and cost.

Step 2 – Anaesthesia

Local anaesthetic is injected to completely numb the tooth and surrounding area. You should feel no pain during the procedure. If you are anxious, sedation options (such as nitrous oxide or oral sedation) can be arranged before the appointment. Your dentist will not begin work until you confirm the tooth is fully numb.

Step 3 – Isolation with a rubber dam

A small sheet of rubber (dental dam) is placed over the tooth, isolating it from the rest of your mouth. This serves two purposes: it prevents bacteria from your saliva from entering the tooth during treatment, and it prevents the small instruments and irrigating solutions from entering your throat. The dam is held in place with a clamp and is painless.

Step 4 – Access opening

Your dentist drills a small opening through the biting surface of the tooth (for a back tooth) or the back surface (for a front tooth) to access the pulp chamber inside. Any remaining decay is also removed at this stage.

Step 5 – Pulp removal and canal shaping

Using very fine, flexible instruments called endodontic files, the dentist removes the infected or inflamed pulp tissue from the pulp chamber and each root canal. The canals are then shaped (widened slightly in a tapered form) to allow thorough cleaning and to create space for the filling material. An electronic apex locator is used to determine the exact length of each canal – this ensures the entire canal is cleaned without extending beyond the root tip.

Step 6 – Cleaning and disinfection

Throughout the shaping process, the canals are flushed repeatedly with antimicrobial irrigating solutions (typically sodium hypochlorite) to dissolve remaining tissue, kill bacteria and wash out debris. This irrigation step is critical to the success of the treatment.

Step 7 – Filling and sealing the canals

Once the canals are clean, dry and free of infection, they are filled with a biocompatible rubber-like material called gutta-percha, combined with a sealer cement. The material is packed tightly into each canal to seal the space and prevent bacteria from re-entering. The access opening is sealed with a temporary or permanent filling.

Step 8 – Restoration (crown or filling)

After the root canal is completed, the tooth needs a final restoration to protect it and return it to full function. For back teeth, this is almost always a crown. For front teeth with minimal structural loss, a filling may be sufficient. Your dentist will discuss the recommended restoration and timeline – typically the crown is placed within 2-4 weeks of the root canal.

Does a root canal hurt? Managing pain and anxiety

The reputation of root canal treatment as painful is outdated. Modern techniques, anaesthetics and instruments have made the procedure comparable to having a routine filling.

During the procedure

The tooth is completely numb under local anaesthetic. You will feel pressure, vibration and the sensation of instruments working inside the tooth, but you should not feel sharp pain. If at any point you feel discomfort, tell your dentist immediately – additional anaesthetic can be administered.

Teeth with active, acute infection can sometimes be more difficult to numb completely. If your dentist anticipates this, they may prescribe antibiotics for a few days before the appointment to reduce the infection, which allows the anaesthetic to work more effectively.

After the procedure

Once the anaesthetic wears off (2-4 hours), mild to moderate aching is normal. This is inflammation in the tissues around the root tip, not inside the tooth itself. Pain typically peaks within the first 24-48 hours and then steadily improves.

Pain management after root canal treatment:

• Ibuprofen (Nurofen): 400 mg every 6-8 hours with food – effective for both pain and inflammation
• Paracetamol (Panadol): 500 mg-1 g every 4-6 hours – can be alternated with ibuprofen for stronger relief
• Avoid aspirin, which can increase bleeding
• Do not chew on the treated tooth until the final restoration (crown) is placed

If pain is severe, worsening after 3 days, or accompanied by significant swelling, contact your dentist. These are uncommon but can indicate a complication that needs attention.

For anxious patients

If dental anxiety is a concern, discuss sedation options with your dentist before the appointment. Nitrous oxide (happy gas), oral sedation and IV sedation can all be used during root canal treatment. You do not need to endure anxiety – effective options exist and your dentist will work with you to find the right approach.

Recovery timeline

Day 1 (treatment day): Numbness wears off in 2-4 hours. Mild aching begins. Take pain relief before the anaesthetic fully wears off. Avoid eating on the treated side. Eat soft foods.

Days 2-3: Some tenderness when biting is normal. Pain should be mild and manageable with over-the-counter medication. Continue avoiding hard or crunchy foods on the treated side.

Days 4-7: Most patients feel back to normal. Tenderness on biting should be minimal or gone. Resume normal diet, but continue to be careful on the treated tooth until the crown is placed.

Weeks 2-4: Crown appointment. Once the crown is fitted, the tooth is fully protected and you can chew normally on it.

The root and surrounding bone continue to heal over the following months. A follow-up X-ray (usually at 6-12 months) confirms that any pre-existing infection has resolved and the bone around the root tip is healthy.

Root canal versus extraction – which is the right choice?

The decision between saving a tooth with root canal treatment and extracting it depends on several factors.

When root canal treatment is usually preferred

• The tooth has a good long-term prognosis (sufficient remaining structure, no vertical root fracture, adequate bone support)
• Keeping the natural tooth preserves chewing function, appearance and alignment of surrounding teeth
• The overall cost of root canal plus crown is comparable to extraction plus replacement (implant or bridge)

When extraction may be the better option

• The tooth is cracked vertically below the gum line (a vertical root fracture cannot be repaired)
• Insufficient tooth structure remains to support a crown – the tooth would fracture even after restoration
• The root canals are severely calcified or have unusual anatomy that prevents adequate cleaning
• The tooth has a very poor prognosis and the resources would be better spent on a predictable replacement
• Budget constraints – in some cases, a simple extraction with no immediate replacement may be more practical, though the long-term consequences of a missing tooth (shifting teeth, bone loss, bite changes) should be considered

Your dentist will give you an honest assessment of the prognosis and help you weigh the options. There is no one-size-fits-all answer.