The nerve inside a tooth has one response to being damaged, whatever the cause: it becomes inflamed, and then it dies. A root canal is how we clean out that dead or dying tissue and save the tooth. The difficulty is that the symptoms arrive in a sequence most people misread - and the single most misleading moment is the one where it stops hurting.
The symptoms that point to a root canal
- Pain that lingers. Sensitivity that vanishes a second after the cold goes is normal dentine sensitivity. Pain that carries on for 30 seconds or several minutes after the stimulus is gone suggests the nerve is inflamed.
- Pain that wakes you at night, or that starts on its own without you biting or drinking anything.
- Pain on heat specifically - a tooth that hurts with hot tea but is soothed by cold water is close to a classic sign of a dying nerve.
- Tenderness on biting, or the tooth feeling slightly "high", as if it is hitting first when you close.
- A tooth that has darkened or greyed compared with its neighbours, often years after a knock.
- A small pimple or gum boil on the gum near the root, which may leak a bad-tasting discharge and then reappear.
- Swelling of the gum, cheek or face on that side.
You do not need all of these. Two or three together, in the same tooth, is enough to get it imaged.
Why the pain stopping is the worst sign
This is the part worth reading twice. A tooth can throb agonisingly for two or three days and then go quiet, and almost everyone reads that as the problem resolving. It usually is not. It often means the nerve has finished dying - so there is nothing left inside to generate pain.
The infection does not stop when the nerve does. It carries on down the canal and out of the root tip into the bone, where it builds slowly and silently, sometimes for months or years, before announcing itself as a swelling or an abscess. Patients regularly tell me a tooth "was fine since last year" - and the X-ray shows a dark shadow at the root that has been quietly eating bone the whole time. If a tooth hurt badly and then stopped, get it checked precisely because it stopped.
What is not a root canal
Plenty of tooth pain is not nerve damage, and it is worth ruling the simpler things out before agreeing to treatment. A sharp zing on cold that disappears immediately is usually sensitivity from worn enamel or a receded gum, treated with a desensitising agent or a small filling. Pain from food packing between two teeth is a contact problem. Generalised aching across several upper back teeth during a cold is frequently the sinus rather than any tooth at all - our winter dental care guide explains how to tell them apart.
A shallow cavity that has not reached the nerve needs a filling at ₹1,000-₹3,500, not a root canal. If you are told you need root canals on several teeth at once and none of them have been hurting, that is a reasonable moment to get a second opinion - an online consultation with your X-rays is a cheap way to do it.
Which symptoms are an emergency
Most of the signs above mean book an appointment this week. These mean today:
- Facial swelling, especially if it is spreading towards the eye or under the jaw
- Difficulty swallowing, breathing, or opening your mouth more than a couple of centimetres
- Fever alongside dental pain
- Pain that no ordinary painkiller touches at all
A spreading dental infection is not a dental inconvenience, it is a medical problem, and the floor of the mouth and the tissues around the eye are the two directions that matter. Do not wait it out at home. Our emergency guide covers the first hour, and what to do about pain at night covers getting through until morning.
Antibiotics are not a treatment
Antibiotics reduce the swelling and the pain, and they are genuinely useful when infection has spread into the surrounding tissue. What they cannot do is sterilise the inside of a tooth. There is no blood supply left in a dead canal for the drug to arrive through - which is why the pain returns a week or two after the course finishes, every time.
Cycling through repeated courses of antibiotics for the same tooth is common in Delhi and it achieves nothing except delay and resistance. The infection is inside the tooth. It only leaves when the canal is cleaned out or the tooth is removed.
How it is confirmed
Symptoms narrow it down; they do not confirm it. Diagnosis is an X-ray of the tooth - which shows decay reaching the nerve, or the dark shadow of infection at the root tip - combined with simple vitality tests to check whether the nerve is alive, and tapping the tooth to see whether the ligament around it is inflamed. Our guide on which dental X-ray you actually need explains the options; for a single suspect tooth it is a ₹200-₹400 IOPA.
If it is confirmed, treatment is a root canal followed by a crown on back teeth. The cost depends on which tooth it is - ₹4,500-₹11,000 for the root canal, plus the cap - and our root canal cost guide breaks down exactly what drives the seven-fold price spread you will find across Delhi clinics.
What waiting costs
A tooth caught while the nerve is still inflamed is a straightforward single-visit root canal. The same tooth six months later, once infection has destroyed bone at the root tip, may need re-treatment, a surgical procedure at the root end, or extraction and an implant at ₹28,000 upwards. The gap between those two outcomes is usually a few months of ignoring a symptom that had gone quiet.
If any of this sounds like the tooth you have been living with, get it looked at. We see patients from Mayur Vihar Phase 1, Mayur Vihar Phase 3, Patparganj, Pandav Nagar, Vasundhara Enclave, Noida and Indirapuram. Book an appointment and we will tell you honestly whether it needs a root canal or something far smaller.