01What is Root Canal Treatment?
Root Canal Treatment removes the damaged nerve inside a tooth caused by a cavity or trauma, then fills the space to preserve the tooth.
The medical term for root canal treatment is Root Canal Treatment (Endodontic Treatment). Inside each tooth is a narrow passage (the root canal) containing nerves and blood vessels; when it becomes infected, severe pain can occur and the tooth may ultimately need extraction. Root Canal Treatment removes the infected tissue and thoroughly disinfects and seals the canal as the final stage of tooth-preserving treatment to save the tooth.
Understanding tooth anatomy
| Structure | Location | Function |
|---|---|---|
| Enamel | Outermost layer | Hardest tissue in the human body; external protection |
| Dentin | Beneath the enamel | Main body of the tooth; transmits nerve sensations |
| Pulp | Innermost hollow chamber | Nerves, blood vessels, and connective tissue — the target of Root Canal Treatment |
| Root Canal | Internal passage within the root | Passageway through which the pulp runs |
| Apex | Root tip | Exit where nerves and blood vessels leave into the jawbone |
Conditions requiring Root Canal Treatment
- Irreversible Pulpitis: Decay has reached the pulp, causing inflammation that cannot heal on its own
- Pulp Necrosis: The pulp is completely dead and usually progresses to a chronic infection
- Periapical Abscess: Bacteria from the dead pulp spread to the root tip and surrounding bone, forming pus
- Traumatic dental injury: A blow or traffic accident can expose the pulp or cause it to die
- Severe wear or cracks: When a deep crack extends to the pulp
02Symptoms that may require Root Canal Treatment
If the pulp is affected, you may notice the following signs. If any apply, an early checkup is recommended.
Common warning signs
- Throbbing pain even at rest: Called "spontaneous pain," an almost certain sign for Root Canal Treatment; often worse when lying down
- Severe pain to cold water or hot foods + persists long after the stimulus: If it lasts 30 seconds or more, a high likelihood of Irreversible Pulpitis
- Tenderness when biting on a specific tooth: A sign that inflammation is progressing in the periapical (root tip) area
- Small bump on the gums or pus draining from a small opening: A "fistula," a sign of a chronic periapical abscess
- Tooth discoloration: If a tooth turns gray or brown after trauma, the nerve may have died
- Severe pain not responding to strong pain relievers: Pain does not improve with over-the-counter pain relievers
- Pain that keeps you from sleeping at night: Emergency Root Canal Treatment or an emergency pulpectomy may be needed
When Root Canal Treatment is needed even without symptoms
Below are situations that may be found on imaging even if the patient does not feel pain.
- Chronic pulp necrosis (the nerve is already dead, so there is no pain)
- Chronic apical abscess with drainage through a sinus tract
- Progressive nerve death from deep nerve irritation during prior cavity treatment
- Found during a nerve evaluation before making a Crown or other prosthetic work
The trap of "If it stops hurting, isn't that a good sign?"
When a toothache is severe for a few days and then suddenly disappears, many people think it has "gotten better." But in reality, the nerve has completely died and can no longer send pain signalsis likely. A dead nerve becomes a "culture medium" for bacteria; the infection then spreads to the root tip and progresses to an apical abscess that destroys the surrounding bone. Leaving it alone just because the pain is gone puts you at very high risk of losing the tooth.
03Root Canal Treatment Fees (2026)
Root Canal Treatment is covered by Korean NHIS. Costs vary by tooth location (number of canals).
Covered by Korean NHIS (all ages)
| Tooth location | Number of canals | Total cost (approx.) | Patient coinsurance 30% (adults) |
|---|---|---|---|
| Front teeth (incisors/canines) | 1 canal | Approx. 200,000–300,000 KRW (approx. $146–$219) | Approx. 60,000–90,000 KRW (approx. $44–$66) |
| Premolars | 1–2 canals | Approx. 300,000–400,000 KRW (approx. $219–$292) | Approx. 90,000–120,000 KRW (approx. $66–$88) |
| Molars | 3–4 canals | Approx. 400,000–600,000 KRW (approx. $292–$438) | Approx. 120,000–180,000 KRW (approx. $88–$131) |
| Molars (4 canals/complex) | 4 or more canals | Approx. 500,000–700,000 KRW (approx. $365–$511) | Approx. 150,000–210,000 KRW (approx. $110–$153) |
Note: For patients under age 6 or age 65+, the coinsurance may be lower. After Root Canal Treatment, any needed Crown (prosthetic) is generally non-covered (out-of-pocket)A separate fee applies (about 250,000–1,000,000 KRW, approx. $183–$730).
Microscope-assisted Root Canal Treatment (elective care)
- Standard Root Canal Treatment fee + microscope use fee (about 100,000–300,000 KRW per session, approx. $73–$219)
- When recommended: cases requiring high precision such as complex canals, Root Canal Retreatment, or removal of a separated instrument
Root Canal Retreatment cost
- May be covered by Korean NHIS: Root Canal Treatment fee plus additional fee for removing existing filling material
- With a 30% patient share: about 150,000–250,000 KRW (approx. $110–$183) (molars)
- Additional fee when a microscope is used
Essential after a Root Canal — a Crown
- A tooth after Root Canal Treatment becomes brittle due to loss of nutrient supply, so it must be covered with a Crown
- Standard metal crown: about 250,000–400,000 KRW (approx. $183–$292) (first choice for molars)
- PFM (porcelain-fused-to-metal): about 350,000–550,000 KRW (approx. $256–$402)
- Zirconia crown 550,000 KRW (approx. $400) (excellent esthetics and strength)
- Gold crown: about 800,000–1,500,000 KRW (approx. $584–$1,095) (excellent biocompatibility and precision)
"I already had a root canal—do I need it again?"
If a previous Root Canal Treatment has failed or a new infection has developed, Root Canal Retreatmentmay be necessary. The success rate for Root Canal Retreatment is somewhat lower than for initial treatment—about 70–85%—and it is more complex. Therefore, having the first Root Canal Treatment performed meticulously under a microscope is the most cost-effective approach long term. If retreatment also fails, Apicoectomy or extraction followed by a Dental Implant.
Costs vary by clinic, tooth condition, and whether a microscope is used. Your exact out-of-pocket amount will be provided after diagnosis during consultation.
04Root Canal Treatment process
Root Canal Treatment typically takes 2–4 visits over about 2–4 weeks. The number of visits and duration may vary by tooth condition.
Visit 1: Diagnosis and nerve removal (about 60–90 min)
After X-ray or CT imaging, we confirm the need for Root Canal Treatment. Under local anesthesia, we remove decay and create an access opening into the canal. The infected nerve tissue is removed (pulpectomy), and the canal is measured, cleaned, and disinfected to full working length. Pain usually improves the most after this first visit.
Visit 2: Canal shaping and disinfection (about 30–60 min)
We refine the canal more precisely and eliminate bacteria with sodium hypochlorite, etc. A medicament is placed and the tooth is sealed temporarily. Usually scheduled at 1–2 week intervals; if infection is severe, disinfection may be repeated 3–4 times or more.
Visit 3 (or final): Canal filling (about 30–60 min)
Once disinfection is complete, the canals are densely filled and sealed with gutta-percha and sealer. An X-ray is taken to verify the fill, and the crown portion is restored with a temporary or permanent filling.
Visit 4 (final): Core build-up + Crown fabrication (about 30–40 min × 2 visits)
Within 1–2 weeks after completing the root canal, we make the core (post) and take an impression. About 1 week later, the Crown is placed. A tooth that has had Root Canal Treatment must be covered with a Crown for long-term service. Without a crown, the risk of tooth fracture becomes very high within 6 months–1 year.
When more visits may be needed
- Severe periapical abscess: 1–2 additional disinfection visits
- Complex canal anatomy (curvatures, calcification): microscope-precision treatment required
- Retreatment after a failed prior root canal: extra time for removing the previous filling material
- Root separation or external resorption present: determine after detailed evaluation
05Does Root Canal Treatment really hurt?
With modern Root Canal Treatment and effective anesthesia, there is little to no pain during the procedure. Temporary discomfort for a few days afterward is common.
Pain during the procedure
- Usually, almost none: Pain blocked with local anesthesia
- If anesthesia doesn't work well (severe inflammation): additional anesthesia or a nerve block, or remove part of the nerve as an emergency step, then proceed fully at the next appointment
- If you have severe dental anxiety: Sedation Dentistry is available
Post-treatment pain (normal range)
| Timing | Typical experience | Care tips |
|---|---|---|
| Same day~2 days | Throbbing when tapping the tooth, tenderness when chewing | Prescribed pain reliever, soft foods |
| 3~7 days | Gradual improvement, only mild tenderness remains | Chew on the opposite side of the treated area |
| 1~2 weeks | Mostly back to normal | Avoid hard foods until the Crown is made |
When to return to the clinic
- Severe pain for 3 or more days that isn't controlled by pain medication
- Worsening gum swelling and pus discharge
- Temporary filling comes out and food packs into the tooth
- Fever or lymph node swelling near the treated area
The real reason people think Root Canal Treatment is painful
Most of the belief that "Root Canal Treatment hurts" the severe toothache right before Root Canal Treatmentcomes from. By the time patients decide on Root Canal Treatment, many already have pain bad enough to keep them from sleeping, so that pain gets mentally linked to the procedure. In reality, the pain after Root Canal Treatment is much milder than before the procedure and is well controlled with pain medication. Most people experience significant pain relief within a few hours right after the procedure.
06Root Canal Treatment aftercare
A tooth after Root Canal Treatment is more prone to fracture than a natural tooth. Proper aftercare is important if you want it to last a lifetime.
In the first 1~2 weeks after Root Canal Treatment
- Chew on the opposite side of the treated area: To protect the temporary filling
- Avoid hard or sticky foods: e.g., nuts, ice, caramel
- If prescribed pain medication, take it regularly: Even if the pain is mild, take it on schedule for the first 2~3 days
- No smoking or alcohol: To avoid delayed healing
- Protect the tooth until the Crown is made: After root canal treatment, leaving the tooth without a crown for a long time carries a high risk of fracture
After crown placement (long-term care)
- Brush like a natural tooth (2–3 times a day): Pay special attention to cleaning along the crown margin (gumline)
- Use floss and an interdental brush daily: Key to preventing cavities at the crown margin
- Regular checkups every 6–12 months: Use X-ray to check the root canal area and look for cavities at the crown margin
- If you grind or clench, use a night guard: Root canal–treated teeth have a higher fracture risk—protection is essential
Average lifespan of a root canal–treated tooth
- Generally 10–30 years or longer: with an appropriate crown + regular maintenance
- Most common cause of failure: cavity at the crown margin → may require Root Canal Retreatment or extraction
- Second most common cause: tooth fracture (especially molars and patients who grind their teeth)
- Third most common cause: reinfection from residual bacteria inside the canal
"Do I really need a crown after root canal treatment?"
Many people delay getting a crown due to cost, but for molars that have had root canal treatment, more than about 50% will fracture within 6 months–2 years if left without a crownIf the tooth breaks and the crack extends to the root, it can no longer be saved; after extraction, a Dental Implant — about 1,500,000–2,500,000 KRW (approx. $1,095–$1,825) — is needed. Even though a crown — about 250,000–800,000 KRW (approx. $183–$584) — is not covered by the Korean NHIS, it is ultimately the most economical choice. For front teeth, a precise composite resin filling may substitute for a crown in some cases, so decide after consulting your dentist.
07Root Canal Retreatment and Alternatives
If a previous root canal treatment has failed or reinfection has developed over time, consider the following options.
Signs you may need Root Canal Retreatment
- Pain or tenderness returns in a previously treated tooth
- A new fistula (pus-draining opening) forms on the gum
- On a routine X-ray, a new or enlarging dark shadow at the root tip is seen
- New infection due to a cavity at the crown margin
Success rates of Root Canal Retreatment
- Initial Root Canal Treatment success rate: about 85–95% (higher when using a microscope)
- Root Canal Retreatment success rate: about 70–85% (varies with complexity and microscope use)
- Success rates vary by tooth location, extent of infection, procedural precision, and patient cooperation
When retreatment is difficult — alternatives
| Option | Indication | Cost (approx.) |
|---|---|---|
| Apicoectomy | Failed retreatment; chronic abscess at the root tip | about 300,000–500,000 KRW (approx. $220–$365) |
| Intentional Tooth Replantation (Intentional Replantation) | Very complex canals; other methods not feasible | approx. 500,000~1,000,000 KRW (approx. $365~$730) |
| Dental Implant after extraction | When the tooth cannot be saved | approx. 1,500,000~3,000,000 KRW (approx. $1,095~$2,190) |
| Dental Bridge after extraction | Uses adjacent teeth | approx. 900,000~2,000,000 KRW (approx. $657~$1,460) (3-unit span) |
"The value of saving your natural teeth"
Even though Dental Implants have advanced, no artificial tooth surpasses a natural tooth. A natural tooth is connected to the jawbone by the periodontal ligament (connective tissue), which absorbs micro shock and transmits chewing pressure to the brain for a natural feel. For the same cost, preserving your natural tooth with Root Canal Retreatment takes priority over a Dental Implant—that’s why. However, if saving the tooth is unrealistic, trying too hard could cost you the adjacent jawbone, so the dentist’s judgment is important.
08Frequently Asked Questions
We’ve compiled the questions patients ask most about Root Canal Treatment.
Q.If I get Root Canal Treatment, is that tooth "dead"?
Strictly speaking, only the “nerve (pulp)” is removed; the tooth itself continues to receive nutrients and stimulation through the periodontal ligament connected to the jawbone. However, because it no longer receives internal nutrition, it becomes weaker than a vital natural tooth and may discolor slightly over time. That’s why protecting it with a Crown is essential.
Q.Does one Root Canal Treatment last a lifetime?
When completed successfully, on average 10~30 years or more of function is possible. However, if a cavity forms at the crown margin, the tooth fractures, or residual bacteria cause reinfection, Root Canal Retreatment may be needed. Regular checkups and diligent flossing largely determine longevity.
Q.My temporary filling fell out during Root Canal Treatment. What should I do?
Please visit the dentist as soon as possible. The temporary filling is crucial to block external bacteria; if it stays out for long, the canal can become reinfected. Avoid chewing on that side, keep the area clean with gentle brushing so food debris doesn’t enter the canal, and come in promptly if you have pain or notice debris.
Q.I found out I’m pregnant during Root Canal Treatment. Can I continue?
The safest period is the second trimester (4~6 months of pregnancy). If the first stage of nerve removal is already finished, we can stabilize the tooth with a temporary medication and complete treatment during the second trimester. The local anesthetic used (lidocaine) and common antibiotics (such as amoxicillin) are generally considered relatively safe for pregnancy, but always consult your OB-GYN first and decide on the timing together. X-rays are taken with shielding, using a very small dose.
Q.Can a tooth that had Root Canal Treatment get a cavity again?
Yes. Because a tooth that has had Root Canal Treatment often doesn’t feel pain, decay can progress unnoticed. In particular,between the crown margin and the toothis a common site for cavities, and decay here often advances to the point that the tooth cannot be saved. Regular checkups and flossing are very important.
Q.Do I really need microscope-assisted Root Canal Treatment?
It’s not mandatory in every case, but it’s strongly recommended in the following situations: ① complex canal anatomy (curved or split canals), ② Root Canal Retreatment, ③ removal of a broken instrument is required, ④ a chronic abscess requires detection of fine, hidden cracks. Using a microscope is known to increase success rates by about 10~15%, so if you want the treatment to be a once-in-a-lifetime event, it’s best to have it done precisely from the first procedure.
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