Root canal treatment has a reputation it no longer deserves. The procedure is carried out under local anaesthetic and most patients report it feels much like having a filling. The pain people associate with root canals is the pain that brings them in — the treatment is what stops it.
What follows is what actually happens, so there are no surprises.
Why it is done
Inside every tooth is a chamber containing the pulp: nerve tissue and blood vessels running down through the root. When bacteria reach that space — through deep decay, a crack, repeated fillings or a knock — the tissue becomes inflamed and then dies. It cannot recover on its own, and the infection spreads out through the root tip into the bone.
Root canal treatment removes the damaged pulp, cleans and shapes the canals, and seals them so bacteria cannot return. The alternative is removing the tooth — see our root canal treatment page.
The appointment, step by step
- Examination and radiographs to confirm the diagnosis and to see the shape and length of the roots.
- Local anaesthetic. The injection is the only part most people notice. Say if you are still feeling anything before work starts — more anaesthetic can be given, and no one expects you to be stoical.
- Isolation. A rubber sheet is placed over the tooth to keep the area clean and dry and to stop anything falling to the back of the mouth. It looks unfamiliar and is entirely painless; most patients find it makes the appointment more comfortable, not less.
- Opening the tooth. A small access is made through the biting surface.
- Cleaning and shaping. The canals are cleaned along their full length with fine instruments, irrigated with disinfecting solutions, and shaped so they can be sealed. This is the longest part and it is not painful — the tissue being removed is already damaged, and the tooth is numb.
- Filling and sealing the canals.
- A temporary or permanent seal over the access, and a radiograph to confirm the result.
How long it takes
A front tooth with one canal is quicker than a back molar with three or four. Expect roughly an hour to an hour and a half per visit. Some teeth are completed in a single appointment; others are treated over two, with a dressing in between if infection needs time to settle. You will be told which applies to you and why.
Does it hurt?
During: no, once anaesthetised. If a tooth is acutely inflamed it can be harder to numb, and that is worth saying at the outset so extra measures can be taken.
Afterwards: the tooth is commonly tender to bite on for a few days, and sometimes for a week or two, as the tissue around the root tip settles. Ordinary pain relief covers it. It should be improving steadily.
Contact the clinic if pain increases after the first few days rather than easing, if there is swelling, or if the temporary filling comes out.
The days afterwards
- Avoid chewing on that side until the tooth has its permanent restoration, particularly if it has a temporary filling.
- A tooth with only a temporary seal is vulnerable — do not delay the next appointment.
- Continue brushing and cleaning between the teeth normally.
- Take pain relief before the anaesthetic wears off rather than waiting.
Why a crown is often needed afterwards
This is the part patients are least often told clearly. A tooth that has had root canal treatment has lost its internal blood supply and has had structure removed both by the decay and by the access made during treatment. Back teeth in particular become more brittle and are at real risk of splitting under chewing load — and a tooth that splits below the gum usually cannot be saved at all.
A crown, or sometimes an onlay, distributes the load and protects it. This is a separate stage and a separate cost, and you should be told at the start whether your tooth is likely to need one. Front teeth with minimal loss sometimes do not. See crowns and bridges.
How long does the tooth last?
A well-treated and properly restored tooth can last many years. What ends them, most often, is not the root canal treatment itself but new decay at the margin of the restoration, fracture of an unprotected tooth, or a restoration that leaked and allowed bacteria back in. The tooth still needs cleaning and check-ups like any other — it can still decay, even though it no longer has a nerve to warn you.
What if it does not work?
Most root canal treatments succeed. Where symptoms persist or infection recurs, the options are retreatment — reopening, recleaning and resealing the canals — a small surgical procedure at the root tip, or extraction. None of that is a reason to avoid the initial treatment; it is a reason to have it done carefully and reviewed.
What makes one root canal harder than another
Patients often compare notes and find that one person’s treatment took forty minutes and another’s took two sessions of ninety. The difference is anatomy rather than effort.
Which tooth it is. A front tooth usually has a single, fairly straight canal. An upper molar commonly has three or four, one of which is frequently split in two and notoriously easy to miss. That single anatomical fact accounts for most of the variation in time, cost and success rate between front and back teeth.
Curvature. Sharply curved roots take longer to clean along their full length and require more careful instrumentation.
Calcification. Canals narrow with age and in response to past trauma or deep fillings. A heavily calcified canal can be difficult to locate at all.
Infection. An acutely infected tooth may be harder to anaesthetise and is more often treated over two visits with a dressing in between.
Previous treatment. Retreatment means removing the existing filling material before the canals can be recleaned, which adds a stage.
Asking which category your tooth falls into is a reasonable question, and the answer explains the time and the fee.
What improves the odds
Several things influence the outcome, and some are within your control:
- Treating it earlier. A tooth treated before extensive infection has developed does better than one treated after months of episodes.
- Not delaying the permanent restoration. This is the most commonly neglected factor. A temporary seal is not designed to last; bacteria leak back through it within weeks and can recontaminate canals that were cleaned perfectly. A root canal followed by a delayed crown is a common route to failure, and it is entirely avoidable.
- Protecting a back tooth with a crown or onlay where advised, before it splits.
- Keeping the tooth clean. It has no nerve, so new decay at the margin produces no warning until it is advanced.
- Attending the review. Healing at the root tip is assessed radiographically at intervals, typically over the following year.
If money is tight and you have to choose between the root canal and the crown, say so — the sequencing can sometimes be planned around it, and that conversation is far better had in advance than after a tooth has fractured.
Frequently asked questions
Should I just have the tooth out instead?
Extraction is quicker and usually cheaper on the day. Replacing the tooth afterwards with an implant or a bridge costs considerably more than the root canal would have, and nothing functions quite like your own tooth. Where a tooth is savable, saving it is usually the better decision.
Will the tooth go dark?
Front teeth sometimes darken after root canal treatment. Internal bleaching or a restoration can address it — see why whitening does not work on every tooth.
Do I need antibiotics?
Not usually. Antibiotics do not clear infection inside a root canal, because there is no blood supply to carry them there. They are used for spreading infection alongside the treatment, not instead of it.
Can I go back to work afterwards?
Generally yes. Your lip and tongue will be numb for a few hours — be careful eating and avoid hot drinks.
Is it safe during pregnancy?
Treating infection is usually preferable to leaving it. Tell us you are pregnant so the treatment and any imaging can be planned appropriately.
Get a painful tooth assessed
The earlier a tooth is treated, the more predictable the outcome. See our root canal treatment page and toothache: what the pain is telling you.
To arrange a consultation at our clinic on Abbas El-Akkad in Nasr City, call +20 101 969 7597 or message us on WhatsApp.
