Root Canal Procedure Explained: What Happens, How Long It Takes, and Does It Hurt

April 25, 2026

What Is a Root Canal?

A root canal (technically called endodontic therapy) removes infected or inflamed pulp tissue from inside a tooth. The pulp — the soft interior containing nerves and blood vessels — can become infected from deep decay, a cracked tooth, or trauma. Once the pulp is infected, it cannot heal on its own.

The procedure saves the natural tooth rather than extracting it. Keeping your natural tooth is almost always preferable to extraction when the root structure is intact.

Step-by-Step: What Happens During a Root Canal

Step 1 — Diagnosis and X-rays

Your dentist takes periapical X-rays to assess the degree of infection and the anatomy of the root canals. In complex cases, a 3D CBCT scan ($150–$300) may be taken. Signs that a root canal is needed include a persistent toothache, swelling, sensitivity to heat that lingers, or a visible abscess on the gum.

Step 2 — Anesthesia

Local anesthetic (typically lidocaine) is injected into the gum tissue around the tooth. If the tooth is severely infected, a second injection or a different anesthetic may be needed to achieve full numbness. You should feel no sharp pain once properly anesthetized.

Step 3 — Access Opening

A small hole is drilled through the top of the tooth to reach the pulp chamber. A rubber dam (thin sheet of latex or latex-free material) is placed to isolate the tooth and keep the area dry and clean.

Step 4 — Canal Cleaning and Shaping

Using thin, flexible nickel-titanium files — many now driven by a rotary motor — the dentist removes the infected pulp tissue and shapes the canals to accept the filling material. Irrigation with sodium hypochlorite solution disinfects the canal system throughout this stage.

Step 5 — Filling the Canals

Once the canals are clean, dried, and shaped, they are filled with gutta-percha (a rubber-like material) and sealed with dental cement. This sealing is critical — any gap can allow reinfection.

Step 6 — Crown Placement

A root canal tooth loses its blood supply and becomes brittle over time. In the vast majority of cases, a crown is placed within a few weeks to protect the tooth from fracture. Front teeth with minimal structural loss are sometimes restored with a filling alone.

Recovery: What to Expect

Mild to moderate soreness for 2–4 days after the procedure is normal as the ligament around the root heals. Ibuprofen (400–600 mg every 6 hours) or acetaminophen typically manages this well. Avoid chewing hard foods on the treated tooth until the crown is placed.

Call your dentist immediately if you experience severe pain, swelling, or a fever — these can indicate residual infection requiring additional treatment or a prescription antibiotic.

General Dentist vs. Endodontist

General dentists are trained to perform root canals on straightforward cases — typically single-rooted front teeth and premolars. Molars with three or four canals, curved roots, or calcified canals are more complex and are often referred to an endodontist (a root canal specialist with 2–3 years of additional training beyond dental school).

If your general dentist refers you to a specialist, it is a sign of careful judgment, not a lack of competence. Endodontists perform root canals exclusively and use advanced microscopes and imaging that improve outcomes on difficult anatomy.