Root Canal Treatment Guide
The Last Line of Defense Before Extraction — Know It Well Before You Get It
Root canal treatment is the final stage of conservative treatment that saves a tooth without extracting it. Why does it hurt, how much does it cost, how many visits are needed, and what makes plasma canal disinfection different — Dr. Tae-yoon Jang of Seongmo Dental Clinic near Sungshin Women’s University Station has compiled this from the questions he receives most often in the clinic.
01What Is Root Canal Treatment
The precise name for root canal treatment is root canal treatment. Inside a tooth there is a thin passage (the root canal) through which nerves and blood vessels pass; when this passage becomes infected with bacteria due to decay or a crack, it causes severe pain, and if left untreated, the tooth must be extracted. Root canal treatment removes the infected nerve tissue, disinfects the passage, and seals it completely — treatment that saves the tooth without extracting it.
Not “a Treatment That Kills the Nerve” but “a Treatment That Saves the Tooth”
Even after the nerve is removed, the tooth does not die. The tooth continues to be supported by the periodontal ligament and jawbone surrounding the root, and the chewing sensation is also maintained. However, since the internal nutrient supply is cut off, it becomes more prone to fracture than before, so protecting it with a crown after treatment completes the root canal treatment.
If a tooth that needs root canal treatment is left untreated, the infection spreads past the root tip to the jawbone (periapical abscess). Once it reaches this stage, treatment takes longer, and in the worst case leads to extraction followed by an implant. Root canal treatment is the last conservative stage that breaks this chain.
02These Symptoms Mean You Need an Exam
- Throbbing pain even at rest — Spontaneous pain that worsens especially when lying down is a classic sign of nerve inflammation.
- Pain lasting more than 30 seconds after contact with cold or hot food — Unlike brief sensitivity, if the pain continues after the stimulus ends, it is likely an irreversible inflammation.
- Throbbing pain in one specific tooth when chewing — This may indicate inflammation at the root tip is progressing.
- A small, millet-seed-sized pus pocket on the gum — This is a drainage channel formed by a chronic abscess, and treatment is needed even without pain.
- Tooth turning gray or brown — This may indicate the nerve has died after trauma.
Severe toothache that has lasted for days sometimes stops abruptly. This is not healing, but rather the nerve has completely died and can no longer send pain signals— this may be the case. A dead nerve becomes a habitat for bacteria and quietly progresses to root tip inflammation. Even if the pain has disappeared, if the cause has not been confirmed, an examination is recommended.
When symptoms are ambiguous, Seongmo Dental first checks the extent of decay or cracks with low-dose 3D CT and Q-ray fluorescence analysis, then determines whether root canal treatment is truly needed. In early cases, pulp-preserving treatment that saves the nerve may be enough.
03Before Extraction — The Order of Saving a Natural Tooth
Seongmo Dental Clinic’s treatment philosophy is “Less pain, more preservation”. Among those who have already been recommended an implant elsewhere, there are cases where, upon examination, the tooth can actually be saved with root canal treatment. Here is the order we review before deciding on extraction.
Can the Nerve Be Saved? — Pulp Preservation
Even if decay is deep, if the nerve is still alive, we first attempt to save the nerve itself by removing only the infected area and covering it with a nerve-protecting material.
Can the Tooth Be Saved With Root Canal Treatment?
If the nerve inflammation has reached an irreversible stage, we preserve the tooth with root canal treatment. Most cases are resolved at this stage.
Retreatment
If reinfection occurs at a previously treated site, the existing filling is removed and the canal is disinfected and refilled precisely once again.
Apicoectomy — The Last Attempt
For root tip inflammation that cannot be resolved even with retreatment, the tooth can be saved through apicoectomy, which directly removes only the inflamed area at the root tip through the gum.
If That Still Does Not Work — Post-Extraction Alternative Consultation
We recommend extraction only for teeth that cannot be preserved even after the above steps. At this point, we also explain alternatives such as implants and bridges together with their costs and prognosis.
Dr. Tae-yoon Jang completed the Endodontics program at the University of Pennsylvania, and this order of preservation is the basic framework of treatment at Seongmo Dental Clinic. Related article: I was recommended an implant — can this tooth still be saved? · Apicoectomy — The Final Solution for Root Tip Inflammation
04Cost — Root Canal Treatment Is Covered by Health Insurance
A fact many people do not know is that root canal treatment itself is a health-insurance-covered procedure. The cost varies depending on tooth location because the number of canals differs — front teeth (1 canal) are cheaper than large molars (3-4 canals). The out-of-pocket cost is around tens of thousands of KRW per tooth, which is far more economical for saving a natural tooth than the cost of an implant after extraction.
| Item | Insurance Coverage | Notes |
|---|---|---|
| Root Canal Treatment | Covered (partial out-of-pocket) | Cost varies by number of canals |
| Retreatment | Coverage may apply | Additional process to remove existing filling |
| Plasma Canal Disinfection (Plazen) | No additional cost | Applied by Seongmo Dental with no separate charge |
| Crown/Endocrown After Treatment | Non-Covered | Varies by material and method |
The fees for non-covered items such as crowns are Non-Covered Fee Guidefully disclosed. Before treatment begins, we provide guidance on the total cost, separated into covered and non-covered items, and documents for private insurance claims (such as detailed treatment cost statements) can be issued at the front desk.
05Seongmo Dental’s Root Canal Treatment Process
Precise Diagnosis
We check the extent of infection, the number and shape of canals, and the presence of root tip inflammation using low-dose 3D CT and Q-ray fluorescence analysis. We first determine whether the nerve can still be saved.
Anesthesia That Reduces the Pain Burden
After topical anesthesia, i-ject computer-controlled anesthesia delivers a constant injection speed and pressure, reducing the pain of the anesthetic injection itself. If needed, Quicksleeper intraosseous anesthesia is used together.
Removing the Infected Nerve and Shaping the Canal
The infected nerve tissue is removed and the inside of the canal is shaped. Minimizing mechanical removal to preserve as much of the tooth wall thickness as possible is important for long-term durability.
Plasma Canal Disinfection
After filling the canal with water, plasma is discharged with the Plazen device to disinfect even the biofilm in microscopic passages that instruments cannot reach. The detailed principle is explained in section 6 below.
Canal Filling — Same Day If Conditions Allow
The disinfected canal is completely sealed with filling material. If the infection status and clinical conditions allow, same-day filling reduces the number of visits. What is reduced is the time, not the treatment stages.
Protection With a Crown/Endocrown
With the in-house Primescan scan → Primemill milling → SpeedFire sintering system, a crown can be made and fitted the same day if conditions allow. Afterward, the root tip condition is monitored with regular checkups.
06What Makes Plasma Canal Disinfection (Plazen) Different
The success or failure of root canal treatment ultimately depends on how thoroughly the bacteria inside the canal are removed. The problem is that the root canal has a microscopic branching structure like tree branches, leaving blind spots that instruments and disinfectant alone cannot reach. This is also a major reason retreatment becomes necessary.
Principle
Plazen (Plazen RCT) is a device that fills the canal with water and then discharges plasma through a dedicated tip. The reactive oxygen species generated at this time spread through the water even into microscopic passages, oxidizing and destroying the bacterial cell membrane and biofilm. It operates at low temperature, minimizing damage to surrounding tissue.
What Changes Clinically
| Category | Conventional Disinfectant Rinse | Plasma-Combined Disinfection |
|---|---|---|
| Reaching Microscopic Passages | Limited to where instruments and liquid can reach | Reactive oxygen spreads through the water |
| Resistant Bacteria / Biofilm | Cases where disinfectant alone has limits | Destroys the biofilm structure itself |
| Amount of Canal Removed | Mechanical enlargement needed for disinfection | Minimized enlargement → tooth wall preserved, fracture risk↓ |
| Number of Visits | Multiple visits due to repeated disinfection | Same-day filling possible if conditions are met |
| Cost | — | Seongmo Dental applies it within health insurance coverage at no additional cost |
Plasma disinfection is used not only for root canal treatment but also for retreatment. However, depending on the extent of infection and tooth condition, multiple visits may still be needed, and whether to apply it is determined after diagnosis. Treatment results vary by individual condition.
Related article: The Principle and Features of Plazen Plasma Root Canal Treatment
07The Misconception That “Root Canal Treatment Hurts”
Most of the perception that root canal treatment is painful comes from the severe toothache right before treatment. Since patients often come to the clinic in pain severe enough to prevent sleep, the memory of that pain remains associated with the treatment. In fact, the treatment itself is performed under anesthesia and there is little to no pain during the procedure in most cases; in fact, many patients experience significant pain relief within hours of the first treatment.
- For Those Afraid of the Anesthetic Injection — After topical anesthesia, i-ject computer-controlled anesthesia reduces pain from injection pressure. If inflammation is severe and anesthesia does not work well, Quicksleeper intraosseous anesthesia delivers anesthetic directly inside the bone.
- Pain After Treatment — You may feel a throbbing sensation when tapping the tooth or pressure pain when chewing for a few days. This is managed with prescribed medication and mostly normalizes within 1-2 weeks.
- When You Should Come Back — Please contact us if pain persists for more than 3 days despite medication, swelling that keeps worsening, or if you have pus or fever.
08Crown After Treatment — Same-Day Completion and Endocrowns
A tooth that has had root canal treatment loses its internal nutrient supply and becomes more prone to fracture than before. Molars in particular bear concentrated chewing force, so if left unprotected by a crown, they commonly fracture and eventually require extraction. The Crown Completes the Root Canal Treatment.
What Makes Seongmo Dental Different ① — Same-Day Crown
Normally, making a crown requires taking an impression and waiting 1-2 weeks for a lab to make it, but Seongmo Dental has an in-house Primescan intraoral scanner (approx. 20μm precision), Primemill milling equipment, and SpeedFire sintering furnace, so if conditions allow, everything from scanning to fitting is completed the same day. Since treatment finishes while anesthesia is still active, discomfort during the temporary crown period and the risk of reinfection are reduced.
What Makes Seongmo Dental Different ② — Endocrown
When enough tooth structure remains, instead of a conventional crown that shaves down the entire tooth, an endocrown, which is bonded inside the tooth while preserving as much of the remaining structure as possibleis considered. It removes less tooth structure and aligns with the principle of natural tooth preservation, and is a viable option thanks to reinforced ceramic materials such as CEREC Tessera and our in-house fabrication system. Whether it can be applied is determined after diagnosis based on how much tooth structure remains.
Related article: Real Same-Day Prosthetics — The Full Primemill·SpeedFire·Primescan System
09Retreatment and Apicoectomy
Signs That Retreatment Is Needed
- Pain or tenderness recurring in a previously treated tooth
- A new pus opening (fistula) appearing on the gum
- A dark shadow at the root tip found or enlarging on X-ray/CT
- Reinfection due to decay at the crown margin
Retreatment is more challenging than the first treatment because it involves the additional process of removing the existing filling. Seongmo Dental first checks the cause of failure with 3D CT (missed canals, microscopic cracks, root tip inflammation) and combines it with plasma disinfection to aim for removing bacteria even from areas the previous treatment could not reach.
Apicoectomy — If Retreatment Still Does Not Work
If the canal is severely blocked or root tip inflammation remains even after retreatment, approaching from the gum side to directly remove the inflamed area at the root tip along with part of the root tip itself, then seal it in reverse— this is a surgical procedure. It is effectively the last conservative technique that can be attempted before extraction, and Seongmo Dental performs it.
A natural tooth has a periodontal ligament surrounding the root that absorbs minor shocks and senses chewing pressure. No matter how advanced implants become, they cannot fully replicate this sensation. However, forced preservation can sometimes worsen jawbone damage, so the boundary between preservation and extraction is determined through precise diagnosis.
10Care After Treatment
During and Right After Treatment
- Chew on the opposite side from the treated area — protects the temporary filling and weakened tooth
- Avoid hard and sticky foods (nuts, ice, rice cakes, caramel)
- If the temporary filling falls out, do not leave it — visit promptly
- Take prescribed medication as directed until finished
After Crown Placement — What Determines Longevity
- Floss/Interdental Brush Daily — A tooth that has had root canal treatment cannot feel pain, so you will not notice even if decay develops. This is key to preventing decay at the crown margin, the most common cause of failure.
- Regular Checkups — The condition of the root tip can change without symptoms, so X-ray follow-up is needed. Seongmo Dental keeps prosthetic design data on file, allowing quick remaking if the crown is damaged.
- A Night Guard If You Grind Your Teeth — Teeth that have had root canal treatment are especially vulnerable to fracture.
11Frequently Asked Questions
Is root canal treatment very painful?
How much does it cost?
How many times do I need to visit?
Can plasma root canal treatment be received anywhere?
My toothache is gone — can I just leave it?
Do I have to get a crown after root canal treatment?
A tooth I had root canal treatment on before hurts again. Do I need to extract it?
Would it not just be better to extract and get an implant?
I am in the middle of treatment and the temporary filling fell out.
How long will a tooth that had root canal treatment last?
Before You Extract That Tooth, Check One More Time
We first check with low-dose 3D CT whether the tooth can be saved, and explain the preservation treatment plan alongside alternatives.
30 sec from Exit 2, Sungshin Women’s Univ. Station · Tuesday evening hours · Saturday, open through lunch
Tue 9:30–20:00 (Evening)
Sat 9:30–14:30 (No lunch break)
Lunch 13:00–14:30 · Closed Thu/Sun/Holidays
30 sec walk from Exit 2, Sungshin Women’s Univ. Station
Free 2-hour parking with Uta Mall registration
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This content is intended to provide general information about dental treatment and does not guarantee the effectiveness or outcome of any specific treatment. Treatment method, duration, cost, and the possibility of side effects vary depending on individual oral condition, so an accurate diagnosis and treatment plan should always be confirmed through an in-person consultation. Detailed fees for non-covered treatments such as crowns can be found in the Non-Covered Fee Guide.