Why the reputation exists
People arrive for a root canal in severe pain. An inflamed or dying pulp produces one of the worst toothaches there is, often keeping patients awake. The treatment is what stops it. The association between root canals and pain is real, but the causation runs backwards from how it is remembered.
The other reason is historical. Before modern local anaesthetics, rotary instrumentation and magnification, the procedure was genuinely harder and longer.
During the procedure
The tooth and surrounding tissue are numbed with local anaesthetic. Once it takes effect you will feel pressure, vibration and the dentist working, but not pain. If you do feel a sharp sensation, that means the anaesthetic has not fully taken and more is given; say so immediately rather than enduring it.
One situation genuinely resists anaesthesia: a lower molar with an acutely inflamed pulp, where the tissue's altered chemistry reduces how well the anaesthetic works. Supplementary techniques exist for exactly this, including intraligamentary and intrapulpal injections. It is a known problem with known solutions, not something to be endured.
The days afterwards
Expect tenderness on biting for two to four days, sometimes up to a week. This is inflammation in the ligament around the root, not a sign of failure. Paracetamol or ibuprofen as advised handles it in the large majority of cases.
The trajectory is what matters. Discomfort that decreases day by day is normal healing. Pain that increases after day three, or swelling that appears or grows, or fever, means you should contact the clinic. That pattern suggests infection rather than recovery.
Chew on the other side until the tooth is permanently restored. A tooth in a temporary filling is vulnerable, and a fracture at that stage can cost you the tooth.
The comparison worth making
The realistic alternative to a root canal on an infected tooth is extraction. That is also done under local anaesthetic, is not painless afterwards, and leaves a gap that costs ₹12,000 to ₹60,000 to replace with a bridge or implant. The pain question is rarely the deciding one; keeping the natural tooth usually is.
Common questions
How painful is a root canal on a scale of 1 to 10?
During the procedure, with adequate anaesthetic, most patients report it comparable to having a filling. Afterwards, tenderness on biting typically sits at two to four out of ten for a few days and responds to over-the-counter painkillers.
How long does pain last after a root canal?
Two to four days for most people, occasionally up to a week, and it should reduce each day. Pain that worsens after the third day, or new swelling, is not normal and warrants a call to the clinic.
Why does my tooth still hurt after a root canal?
Mild tenderness for a few days is inflammation of the ligament around the root and is expected. Persistent or worsening pain can mean a missed canal, a crack in the tooth, or residual infection, and needs re-examination and usually an X-ray. It does not mean the tooth cannot be saved.
Is extraction less painful than a root canal?
No. Both are done under local anaesthetic, and an extraction usually causes more post-operative discomfort and swelling than a root canal, particularly a surgical one. It also leaves a gap that needs replacing.
Medically reviewed
Reviewed by Dr. Dhanya Saxena, BDS, MHA, FMC, FAOI, oro-dental surgeon and aesthetic physician at Redefine Dental and Facial Aesthetic, Indira Nagar, Lucknow. Dental Council registration 20935. Last reviewed 30 August 2026.
This page is general information, not a diagnosis or a quotation. Prices are prevailing Lucknow market ranges. Your own treatment and cost are determined after an examination.