Advanced Root Canal Therapy in Seoul
For teeth that failed a previous root canal, have curved, narrow or calcified canals, or an abscess at the root tip. 3D CT shows the anatomy before treatment so you know the realistic chances.
- Since 2002
- 13 dentists
- In-house lab
- EN · 中文 · 日本語
Can a failed root canal be treated again?
Often yes. In root canal retreatment, the old filling material is removed, missed or blocked canals are located, and the tooth is cleaned and resealed. Gangnam One Day Dental Clinic uses 3D CT to see canal anatomy and infection before deciding. If the root is cracked or too little tooth remains, extraction and an implant may be more predictable.
Reviewed by Dr. Kim Jin-hwan , Chief Director · Updated October 5, 2026
What makes a root canal 'advanced'
A standard root canal treats a tooth with straightforward anatomy. Some cases are more demanding and need more time, imaging and planning. This page covers those situations.
The common thread is that the dentist cannot see inside the root with a normal X-ray alone. A 3D CT scan shows the number, shape and curvature of canals, cracks and the size of any infection in the bone.
- Retreatment of a previous root canal that has become reinfected
- Extra or missed canals, common in upper molars
- Curved, narrow or calcified (blocked) canals
- Large abscess or lesion at the root tip
- Teeth with old posts or crowns that must be removed first
- Cracked or traumatised teeth needing assessment
Why a root canal fails
Most failures come from bacteria that remain or re-enter the canal system. A canal may have been missed, cleaned short of the root tip, or the seal may have leaked under a broken filling or crown.
Symptoms can appear months or years later: tenderness when biting, a gum boil, swelling, or a dark area on an X-ray that is found by chance. Not every failing tooth hurts, which is why X-ray review at check-ups matters.
Not sure if this is right for you? Send a photo or X-ray — a dentist replies on WhatsApp in English, Chinese or Japanese.
Get a free opinionSave the tooth or replace it?
An honest assessment matters more than trying to save every tooth. If the 3D CT shows a vertical root fracture, severe bone loss or too little tooth left for a crown, retreatment is unlikely to last.
In that case, the clinic's oral surgery and implant teams can plan extraction and a single tooth implant in the same clinic. If the tooth is restorable, it is finished with a crown made in the in-house Oneday Lab; see dental crowns.
| Standard root canal | Advanced / retreatment | |
|---|---|---|
| Typical case | First treatment, simple anatomy | Failed treatment, complex anatomy, abscess |
| Imaging | Digital X-ray | Digital X-ray plus 3D CT |
| Visits | Usually 2–3 | Usually 2–4 |
| Visit length | 45–90 minutes | 60–90 minutes |
| Extra steps | None | Removing old filling, posts or crowns |
| Prognosis | Generally favourable | Depends on root and bone condition |
How it works at Oneday Dental
- Before
Send X-rays and history
Send recent X-rays and details of previous treatment on WhatsApp. The team gives an initial view and visit plan.
- Visit 1
3D CT and diagnosis
Clinical tests, digital X-rays and a 3D CT scan show canal anatomy, cracks and infection. You decide between retreatment and alternatives.
- Visit 1–2
Access and removal
Under local anaesthetic, the old crown, post or filling material is removed and missed or blocked canals are located.
- Visits 2–3
Disinfection and sealing
Canals are cleaned, medicated between visits if infection is significant, then filled and sealed.
- Final
Crown and review
The tooth is protected with a crown or onlay. Healing of the bone is usually checked on X-ray after 6–12 months.
Things to know before you decide
- Retreatment has a lower success rate than a first root canal, and the dentist will discuss your individual prognosis.
- Removing old posts or crowns carries a small risk of root fracture.
- Severely calcified canals may not be fully negotiable; surgery at the root tip or extraction may then be considered.
- Teeth with vertical root fractures cannot be saved with root canal therapy.
- Bone healing around the root tip can take 6–12 months to show on X-ray.
Experience you can check
- 2002Founded in Gangnam — 24 years
- 13Dentists in 5 departments
- 3Clinic buildings, 1,570 m²
- 0.01 mmT-Scan bite-force detail
Vice President, Korean Academy of Stomatognathic Function & Occlusion · author on T-Scan implant occlusion (IGI Global)
Complex Root Canals: common questions
Why does my root-canal-treated tooth hurt again?
What is the success rate of root canal retreatment?
Why do you use 3D CT for root canals?
Is retreatment better than an implant?
How long will I need to stay in Seoul?
How much does advanced root canal therapy cost?
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