CAVITY

Cavity Treatment

The treatment depends on how far the decay has progressed. We first check the extent of the cavity and treat in a way that keeps as much healthy tooth as possible.

Dr. Jeong Jinwoo (board-certified prosthodontist · specialist in integrated dentistry) · written and reviewed · last reviewed 2026-09-12

The short answer

Does a cavity always mean drilling away a lot of tooth?

No. After checking how far the decay has progressed with Q-ray quantitative light-induced fluorescence and X-rays, we remove only the minimum and fill it if it is early, and consider root canal treatment and a crown only when it has reached close to the nerve. We look at ways to save the natural tooth before extraction.

The most important decision in cavity treatment is "how much to remove." The internationally agreed principle is not to drill white-spot lesions, and, for deep cavities near the nerve, not to scrape everything out.[1] Joy Dental Clinic Bongcheon shows you the test results on screen and treats only as much as that tooth needs.

Early cavities

Early decay limited to the enamel is treated by removing only the damaged part and filling it with resin. White-spot lesions are not drilled; they are managed with fluoride and monitoring.

Deep cavities

When decay has progressed deep into the dentin, the tooth is restored with an inlay, onlay or crown to withstand chewing forces. If it is close to the nerve, a procedure to protect the nerve is done first.

Cavities that reach the nerve

When inflammation has reached the nerve, root canal treatment removes the inflammation, and the tooth is then covered and protected with a crown.

How does cavity treatment proceed?

Checking the extent of the cavity. Q-ray quantitative light-induced fluorescence records the fluorescence response of decayed or cracked areas as numbers, and X-rays show the depth in areas the eye cannot see, such as between teeth and under existing fillings. With the naked eye or an explorer alone, it is hard to tell early decay from staining, and conversely, a cavity that looks small on the outside but is wide inside is easy to miss.
Judging the distance to the nerve and the nerve’s condition. From the response to cold, heat and tapping, we check whether the nerve is alive and whether the inflammation is reversible. If pain continues after the stimulus is gone, or there is spontaneous pain, we suspect irreversible pulpitis (Korean) and first decide whether root canal treatment is needed.
Explaining the method and extent. Before treatment, we explain which of resin, inlay or crown suits the depth, location and amount of remaining tooth, whether root canal treatment is needed, and the number of visits and how the cost is made up, and proceed after your consent.
Anesthesia and minimal removal. When needed, a computer-controlled anesthesia device (i-JECT) keeps the injection speed steady to reduce the discomfort of the injection. The principle is to remove only damaged tooth structure and keep healthy structure. For deep cavities near the nerve, we first look for a chance to save the nerve by leaving some softened dentin and covering it with a nerve-protecting material.[1]
Restoration. Small areas are filled directly with resin (Korean) on the same day. If the chewing surface is widely damaged, an impression or a scan with the intraoral scanner (TRIOS 6) is used to make an inlay or onlay (Korean); if most of the tooth is damaged or after root canal treatment, a crown (Korean) is made.
Checking the bite and care instructions. If a restoration is too high, it causes pain when chewing and can lead to cracks, so we check and adjust the bite. We explain sensitivity in the days after treatment, what to be careful about when chewing, and when to come back for a checkup.

How does treatment differ with the depth of the cavity?

Decay progresses from enamel to dentin to the nerve, and how far it has gone decides the treatment and number of visits. Even the same "cavity" is approached differently, as in the table below.

Extent	Treatment usually done	Visits
White spot on the enamel surface (demineralization)	No drilling; fluoride application and brushing correction, then monitoring for 3–6 months	A reversible stage
Within enamel, just before dentin	Minimal removal of the damaged area only, then resin	Usually 1
Middle depth of dentin	Resin, or inlay/onlay (depending on extent and location)	1–2
Deep in dentin, near the nerve	Restoration after nerve-protecting treatment; the nerve is kept if there are no symptoms. If pain develops later, root canal treatment (Korean)	2 or more, including monitoring
Nerve involved (spontaneous pain, night pain)	Root canal treatment → post and crown	3–5
Fracture or decay extending below the gum	If the tooth cannot be preserved, extraction is considered; if possible, gum contouring and then a crown	Varies widely

* A general classification; the actual treatment and number of visits are decided individually after diagnosis.

Resin, inlays and crowns: what is the difference?

Item	Resin	Inlay · onlay	Crown
Used for	Small early cavities	Medium-sized damage, chewing surfaces	Most of the tooth damaged, after root canal treatment
Tooth removal	Minimal	Moderate	Covers the whole tooth
How it is made	Filled directly on the same day	Made after an impression	Made after an impression
Visits	Usually 1	About 2	About 2 (more with root canal treatment)
Health insurance	Light-cured resin covered for permanent teeth of children 12 and under; not covered for adults (glass ionomer fillings are covered)	Not covered	Not covered

* A general comparison; an accurate diagnosis and costs are given individually at the consultation. — As of September 2026

How is the cost determined?

Depth and number of cavities — Even "one cavity" can mean one surface of resin or a crown after root canal treatment, with completely different costs. We explain tooth by tooth after diagnosis.
Restorative material — Varies with the material, such as resin, ceramic inlay or zirconia crown. In some cases a covered material (glass ionomer) can be chosen.
Whether root canal treatment is needed — Root canal treatment is covered by Korean national health insurance. However, the crown (Korean) needed after root canal treatment is not covered.
Health insurance coverage — If you meet the conditions below, treatment is covered by Korean national health insurance.

Health insurance coverage. Glass ionomer fillings and root canal treatment are covered, and light-cured resin fillings for the permanent teeth of children aged 12 and under have been covered since 2019.[4] Resin, ceramic inlays and zirconia crowns for adults are not covered. Before treatment, we explain covered and non-covered items tooth by tooth.

Non-covered costs are explained item by item after diagnosis, and we do not give an estimate with the number of teeth fixed without a diagnosis.

What you can know before the consultation

The base unit is one tooth, and resin, inlay, crown, resin core and post are separate items.
Glass ionomer fillings and root canal treatment are covered by Korean national health insurance. Amalgam fillings are also a covered item, but Joy Dental Clinic does not provide them. Resin, ceramic inlays and zirconia crowns for adults are not covered.
Light-cured resin fillings for the permanent teeth of children aged 12 and under are covered by health insurance.
Non-covered fees are quoted at the same amount as the fee schedule posted in the clinic, and we do not run discounts or promotional prices.

What is decided after examination

Resin, inlay or crown — decided after checking the depth of decay and the amount of tooth that will remain.
Whether root canal treatment is needed — decided by looking at whether decay has reached the nerve, pain, response to cold and heat, and X-ray findings together.
Material — depends on position (front or back), chewing force and aesthetic needs.
When it is finalized — after diagnosis, covered and non-covered items are explained tooth by tooth, and treatment starts after your consent.

Fees for each non-covered item and their reference date are published on our non-covered fee notice. The amounts and item names on that page are the official notice in Korean.Non-covered treatment fees →

When a different approach may suit better

· Early demineralization at the white-spot level — we monitor it with fluoride application and brushing correction, without drilling. Drilling at this stage would be over-treatment.
· When decay reaches the nerve and there is spontaneous pain — covering it with resin will not stop the pain, so root canal treatment (Korean) is done first.
· When the tooth is split below the gum — it is hard to preserve, so extraction is considered, and we then explain implants or bridges.
· When there is no decay but only sensitivity — gum recession or wear at the neck of the tooth may be the cause, so we approach it with gum treatment or desensitizing treatment.
· When you get a great many cavities — the cause (dry mouth, diet, brushing) must be found first to prevent recurrence, rather than treating each one separately.

Nothing hidden

Problems that can occur after cavity treatment, and limitations

Sensitivity after treatment. After treating a deep cavity, the tooth may be sensitive to cold for days to weeks. It usually settles, but if it gets worse or also hurts with heat, it may have progressed to nerve inflammation, so we check again.

Nerve exposure and further treatment. With decay close to the nerve, the nerve may be exposed during removal, or the nerve may not recover after treatment so that root canal treatment becomes necessary. According to the literature, selectively leaving softened dentin in deep cavities reduces the risk of nerve exposure.[1][2]

Secondary decay. If plaque builds up at the edge of a restoration, new decay forms underneath. Resin discolors and wears over time and its margins can open, so we check the margins (Korean) at regular checkups.

Restorations coming loose or breaking. Large resin fillings can break or come out under chewing forces. This is why we recommend an inlay or crown from the start when the damage is extensive.

Limits of root-canal-treated teeth. After root canal treatment, a tooth loses moisture and becomes weaker, so using it without a crown carries a high risk of fracture. Tooth survival after non-surgical root canal treatment is reported at about 86–93% at 10 years, and whether it was protected with a crown greatly affects survival.[3]

Anesthesia. For a few hours after anesthesia, sensation is dull and you may bite your lip or cheek; rarely, bruising or temporary altered sensation occurs. Please tell us about your medications and medical conditions before treatment.

No treatment is free of side effects. We tell you in advance so that you know which changes after treatment are normal and which are signs to have it checked again.

FAQ

Frequently asked questions

Q1 Does cavity treatment hurt a lot?

Most is done under local anesthesia, and a computer-controlled anesthesia device that adjusts injection speed and volume reduces the discomfort of the injection. Sensitivity varies with the depth of the cavity and from person to person; we explain at the consultation.

Q2 Is cavity treatment finished in one visit?

Resin treatment of an early cavity is usually completed in one visit. Inlays and crowns need time to make, so about 2 visits; with root canal treatment, about 3–5 visits.

Q3 How can you tell a cavity from staining?

Staining is pigment on the surface, so it shows no fluorescence response and can be removed by scaling and polishing. We confirm actual demineralization or decay with Q-ray fluorescence and X-rays before deciding on treatment.

Q4 Can a small cavity just be watched?

At the white-spot stage on the enamel surface, progression can be stopped with fluoride and brushing, so we monitor it. Decay that has reached the dentin does not stop by itself, so we recommend treatment. Which applies is judged by examination.

Q5 How long can a tooth last after root canal treatment?

If it is well protected with a crown after root canal treatment and regular checkups are kept up, you can use it as a natural tooth for a long time. The literature reports a 10-year survival rate of about 86–93%, depending on the remaining tooth structure and how it is cared for.

Q6 I had root canal treatment but it still hurts. Did it fail?

Discomfort when chewing for a few days right after treatment is common. If pain continues after several weeks or swelling develops, complex branches inside the root, remaining bacteria or a crack may be the cause, and we consider retreatment or other options.

Q7 I want to replace an old amalgam filling. Is that possible?

There is no need to replace an amalgam filling that is in good condition. We check for secondary decay, cracks or open margins under the existing restoration, and if there is a problem, replace it with resin, an inlay or a crown as appropriate.

Q8 Does health insurance cover cavity treatment?

Glass ionomer fillings and root canal treatment are covered, as are light-cured resin fillings for the permanent teeth of children aged 12 and under. Resin, ceramic inlays and zirconia crowns for adults are not covered; we explain item by item before treatment.

Q9 Is sensitivity after cavity treatment normal?

After treating a deep cavity, the tooth may be sensitive to cold for days to weeks, and it usually settles. If it gets worse, also hurts with heat, or throbs without any stimulus, it may have progressed to nerve inflammation and needs to be checked again.

Q10 What happens if a cavity is left untreated?

Decay does not stop by itself; it progresses inward. Left alone, it can reach the nerve and require root canal treatment, or progress further to extraction, so it is best to check it early.

Q11 I stopped treatment partway at another clinic. Can you continue it?

Yes. We check the state of the previous treatment carefully and then continue. We assess your current condition with a detailed diagnosis and draw up a new plan for the remaining treatment.

Symptom guides and further reading

References

Schwendicke F, Frencken JE, Bjørndal L, et al. Managing carious lesions: consensus recommendations on carious tissue removal. Adv Dent Res. 2016;28(2):58-67. — International Caries Consensus Collaboration (ICCC): recommends selectively leaving softened dentin near the nerve in deep cavities; forced complete removal raises the risk of nerve exposure.
Ricketts D, Lamont T, Innes NP, Kidd E, Clarkson JE. Operative caries management in adults and children. Cochrane Database Syst Rev. 2013;(3):CD003808. — Cochrane review: stepwise or partial caries removal significantly reduces nerve exposure compared with complete removal.
Ng YL, Mann V, Gulabivala K. Tooth survival following non-surgical root canal treatment: a systematic review of the literature. Int Endod J. 2010;43(3):171-189. — Tooth survival after non-surgical root canal treatment: 86% at 2–3 years, 93% at 4–5 years, 87% at 8–10 years; crown restoration is a key factor.
Ministry of Health and Welfare (Korea) notice. Health insurance coverage of light-cured composite resin fillings (permanent teeth, age 12 and under), effective 1 January 2019 (in Korean). — Light-cured resin for permanent teeth of children 12 and under is covered; resin for adults is not covered.

RESERVATION

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This page was written and reviewed by Director Jeong Jinwoo (board-certified prosthodontist and specialist in integrated dentistry) of Joy Dental Clinic Bongcheon, based on standard dental knowledge and the literature above. It is intended as general information; individual treatment plans and costs are given after a detailed diagnosis and consultation.

Last updated: 2026-09-23