In brief: Root canal treatment (RCT) removes infected or inflamed pulp from inside a tooth, disinfects the canals and seals them, so the tooth can be kept instead of extracted. It is done under local anaesthetic, usually over one to three visits, and most back teeth need a crown afterwards to stop them cracking.
What Root Canal Treatment Does
Inside every tooth is the pulp: nerves and blood vessels running through narrow channels (root canals) down to the tip of each root. Deep decay, a crack, a knock to the tooth or repeated large fillings can let bacteria reach the pulp. Once it is badly inflamed or dead, it cannot heal on its own.
Left alone, the infection spreads out of the root tip into the bone and can form an abscess. RCT removes the source of infection from inside the tooth so the bone around the root can heal. The alternative is extraction, followed by an implant, bridge or a gap.
Signs You May Need a Root Canal
- Toothache that lingers after hot or cold is removed, or that wakes you at night.
- Pain on biting or pressing on the tooth.
- Swelling of the gum or face near the tooth.
- A small pimple on the gum that discharges pus (a sinus tract).
- A tooth that has turned grey or dark after an injury.
Some infected teeth cause no symptoms at all and are found only on an X-ray. Equally, sensitivity that fades within seconds usually does not mean the pulp is dying.
Is Root Canal Treatment Comfortable?
For most patients, yes. The reputation for pain comes from older techniques and from the infection itself: an inflamed or abscessed pulp is what hurts, and removing it relieves that pain. With good local anaesthetic, you usually feel pressure and movement but not sharp pain, and if you do feel anything, more anaesthetic is given before continuing.
A very inflamed tooth can be harder to numb. The dentist may then give a supplementary injection, or place medication and finish at the next visit once the inflammation settles.
Modern instruments that make the procedure easier
- Electronic apex locators measure each canal's length so files work to the right depth and do not push past the root tip, a common cause of soreness afterwards.
- Nickel-titanium (NiTi) rotary files are flexible, follow curved canals that stiff steel files cannot.
- Irrigation with sodium hypochlorite dissolves pulp tissue and kills bacteria where files cannot reach.
- Warm gutta-percha techniques, such as warm vertical compaction, adapt the filling to irregular canal shapes.
More is on our root canal treatment page.
How the Diagnosis Is Made
The dentist asks about the pain, then tests the tooth: cold tests, tapping and biting tests, and gum probing to look for cracks. These show whether the pulp is still alive, inflamed or dead.
A periapical X-ray shows decay depth, the shape of the canals and any dark area of infection at the root tip. For curved roots, extra canals, suspected cracks or retreatment, a CBCT 3D scan gives a much clearer view. If the tooth is cracked deep into the root or too broken to restore, extraction may be the better option, and this should be discussed before starting.
RCT is also not suitable when the tooth has too little gum and bone support to last, when a vertical root fracture is present, or when the remaining tooth cannot hold a filling or crown. In these cases extraction is the sounder choice.
Root Canal Treatment Step by Step
1. Anaesthetic and isolation
The tooth and surrounding gum are numbed with local anaesthetic. A rubber dam (a thin sheet around the tooth) keeps saliva and bacteria out of the canals and stops instruments or rinses going into the mouth. Patients who are very anxious can discuss sedation options.
2. Access opening
A small opening is made through the biting surface (or the back of a front tooth) into the pulp chamber. Old fillings and decay are removed so the dentist can see all the canal openings. An operating microscope helps locate small or hidden canals.
3. Cleaning and shaping
Each canal's length is measured with an electronic apex locator and X-rays. Fine rotary and hand files remove the pulp and shape the canal, while disinfecting solutions such as sodium hypochlorite wash out bacteria and debris. This is the most important stage for long-term success.
4. Medication between visits (if needed)
If there is active infection, swelling or the canals are complex, calcium hydroxide paste is placed inside the canals and the tooth is closed with a temporary filling for one to a few weeks.
5. Filling the canals
Once the canals are clean and dry, they are filled with gutta-percha (a rubber-like material) and a sealer to block the space from bacteria. An X-ray confirms the fill reaches close to the root tips.
6. Sealing the top of the tooth
A sealing filling or core build-up is placed over the canals. A temporary filling is not enough for long: if it leaks, bacteria can re-enter the canals.
How Many Visits Does It Take?
Many root canals are completed in a single visit of roughly one to two hours, especially when the tooth is not acutely infected. Teeth with abscesses, swelling, very curved or calcified canals, or retreatment cases usually take two or three visits.
Front teeth usually have one canal, premolars one or two, and molars three or four, so molars take longer. The crown is a separate step afterwards.
Why a Crown Usually Follows
A root-canal-treated back tooth has lost its pulp and, more importantly, a large amount of its structure through decay and the access opening. Molars and premolars without cusp protection are much more likely to split under chewing forces, and a vertical split often means the tooth cannot be saved.
For most back teeth, the dentist recommends a crown or a cusp-covering onlay once the tooth is settled, often within a few weeks. Front teeth with little damage can sometimes be restored with a filling alone. Options are explained on our ceramic and zirconia crowns page. See our fees for current costs of RCT and crowns.
Aftercare and Recovery
- Do not chew on the side until the numbness wears off.
- Tenderness on biting for a few days is common; regular painkillers such as ibuprofen or paracetamol usually manage it, if suitable for you.
- Avoid hard or sticky food on the tooth until the crown is fitted, as the tooth is weak.
- Call the clinic if you get swelling, severe pain after the first few days, or the temporary filling falls out.
- Brush and floss normally. The tooth can still decay at its edges.
Success Rates and When a Root Canal Needs Redoing
Studies usually report that 85-95% of first-time root canal treatments are successful over the long term, depending on the tooth and the case. The quality of the seal on top (the filling or crown) matters as much as the canal cleaning: a tooth that leaks from above can become reinfected however well the canals were cleaned. When one fails, common reasons are a missed canal, canals not cleaned to full length, a leaking filling or crown that lets bacteria back in, or a new crack.
Retreatment means removing the old filling material, finding and cleaning any missed canals and resealing the tooth. CBCT and the microscope are especially useful here. Where retreatment through the crown is not possible, a small surgical procedure at the root tip (apicoectomy) may be an option. Read more in our guide to root canal retreatment.
FAQs
Does root canal treatment hurt?
With local anaesthetic, the procedure itself usually feels like a long filling. The pain people associate with root canals is mostly from the infection beforehand, which the treatment relieves.
Is it better to just remove the tooth?
Keeping a restorable natural tooth is usually the better choice for chewing, bone and neighbouring teeth. Extraction makes sense when the tooth is cracked into the root or cannot be rebuilt. Your dentist should explain both options with the X-rays in front of you.
How much does root canal treatment cost?
Root canal treatment at Dazzle starts from ₹10,000. The final cost depends on the tooth, whether it is a first treatment or a retreatment, and the crown or onlay chosen afterwards. Your quote follows the examination and X-rays or CBCT.
Will the tooth turn dark after a root canal?
It can, especially if pulp tissue or blood products remain in the crown of the tooth. A darkened front tooth can usually be lightened by internal bleaching, where a whitening agent is placed inside the tooth for a short period; internal bleaching starts from ₹7,000.
Can I fly or travel after RCT?
Yes, usually the next day. Between visits, the clinic plans the steps around your travel dates.
Have a toothache that lingers or a swelling near a tooth? Book a Consult at our Bandra West or Kemps Corner clinic.
