Cavities in Korea: Stages, Filling Materials, Health Insurance and Post-Treatment Sensitivity
An analysis of 10,789 patient comments on Korean YouTube dental content about Cavities found that questions about Choosing a filling material (resin, inlay, etc.) were the most common (1,457). A cavity (tooth decay) does not heal once a hole forms. This guide covers decay stages, when early decay can be watched, resin vs. inlay vs. crown, what Korea's health insurance covers, and sensitivity after treatment. SOURCE Analysis of patient comments on YouTube dental content (DentStat) · public sources listed under References · Data as of June 28, 2026
Key facts
| Nature of the disease | Progressive: once a hole (cavity) forms, it does not heal on its own [1] |
|---|---|
| Early decay | At the surface demineralization (white spot) stage, care such as fluoride application can sometimes remineralize the tooth [1] |
| Covered filling materials | Amalgam and glass ionomer; light-cured resin for permanent teeth in children aged 12 and under [2] |
| Dental sealants | Covered by National Health Insurance for first and second molars up to age 18 [2] |
| Most common patient question | Choosing a filling material (1,457 of 4,581 question-type comments) [4] |
Cost statistics (non-covered, official HIRA data)
HIRA non-covered treatment fee statistics. National figures are for dental clinics · as of July 6, 2026.
| Item | Basis | Min | Median | Average | Max |
|---|---|---|---|---|---|
| Onlay (gold) | Official, dental clinics | 250,000 KRW | 450,000 KRW | 462,786 KRW | 4,000,000 KRW |
| Inlay (gold) | Official, dental clinics | 35,000 KRW | 400,000 KRW | 408,242 KRW | 2,500,000 KRW |
| Inlay (CAD/CAM ceramic) | Official, dental clinics | 190,000 KRW | 300,000 KRW | 318,742 KRW | 600,000 KRW |
| Inlay (porcelain/ceramic) | Official, dental clinics | 150,000 KRW | 300,000 KRW | 316,046 KRW | 2,500,000 KRW |
| Inlay (resin) | Official, dental clinics | 70,000 KRW | 300,000 KRW | 290,305 KRW | 750,000 KRW |
| Light-cured composite resin (decay, 3+ surfaces) | Official, dental clinics | 30,000 KRW | 150,000 KRW | 146,921 KRW | 900,000 KRW |
| Light-cured composite resin (fracture) | Official, dental clinics | 20,000 KRW | 130,000 KRW | 137,590 KRW | 650,000 KRW |
| Light-cured composite resin (decay, 2 surfaces) | Official, dental clinics | 30,000 KRW | 120,000 KRW | 124,161 KRW | 700,000 KRW |
| Light-cured composite resin (decay, 1 surface) | Official, dental clinics | 20,000 KRW | 100,000 KRW | 94,345 KRW | 600,000 KRW |
| Light-cured composite resin (abrasion) | Official, dental clinics | 10,000 KRW | 70,000 KRW | 72,165 KRW | 400,000 KRW |
Onlay (gold): by province
| Province | Basis | Min | Median | Average | Max |
|---|---|---|---|---|---|
| Seoul | Official, regional | 106,666 KRW | 450,000 KRW | 475,488 KRW | 4,000,000 KRW |
| Busan | Official, regional | 250,000 KRW | 450,000 KRW | 452,659 KRW | 800,000 KRW |
| Incheon | Official, regional | 280,000 KRW | 450,000 KRW | 458,937 KRW | 1,120,000 KRW |
| Daegu | Official, regional | 211,000 KRW | 450,000 KRW | 485,332 KRW | 1,000,000 KRW |
| Gwangju | Official, regional | 300,000 KRW | 470,000 KRW | 496,390 KRW | 850,000 KRW |
| Daejeon | Official, regional | 300,000 KRW | 450,000 KRW | 463,569 KRW | 850,000 KRW |
| Ulsan | Official, regional | 330,000 KRW | 500,000 KRW | 485,101 KRW | 750,000 KRW |
| Gyeonggi | Official, regional | 250,000 KRW | 450,000 KRW | 451,270 KRW | 1,000,000 KRW |
| Gangwon | Official, regional | 300,000 KRW | 450,000 KRW | 468,988 KRW | 913,920 KRW |
| Chungbuk | Official, regional | 300,000 KRW | 450,000 KRW | 454,798 KRW | 900,000 KRW |
| Chungnam | Official, regional | 280,000 KRW | 450,000 KRW | 456,561 KRW | 851,000 KRW |
| Jeonbuk | Official, regional | 300,000 KRW | 450,000 KRW | 466,993 KRW | 800,000 KRW |
| Jeonnam | Official, regional | 300,000 KRW | 450,000 KRW | 474,587 KRW | 800,000 KRW |
| Gyeongbuk | Official, regional | 250,000 KRW | 450,000 KRW | 462,164 KRW | 850,000 KRW |
| Gyeongnam | Official, regional | 250,000 KRW | 450,000 KRW | 472,804 KRW | 900,000 KRW |
| Jeju | Official, regional | 350,000 KRW | 450,000 KRW | 457,959 KRW | 900,000 KRW |
| Sejong | Official, regional | 300,000 KRW | 450,000 KRW | 470,493 KRW | 798,400 KRW |
These figures aggregate HIRA’s public non-covered fee data and are not the price of any particular clinic. "Official" values are statistics published by HIRA (sample size not disclosed); "N dental hospitals" is our own aggregation of the institutions’ reported data (groups with fewer than 5 are not shown). Actual costs depend on the patient’s condition and the scope of treatment. Source: HIRA non-covered treatment fee information (KOGL Type 1). Amounts are in Korean won (KRW).
What do patients ask about most?
Analysis of 10,789 patient question comments on YouTube content about Cavities (collected June 28, 2026).
How do cavities form and progress?
A cavity (dental caries, or tooth decay) is a disease in which acid, produced when mouth bacteria break down sugar, dissolves the tooth surface [1]. At first the surface only turns white from demineralization, but as decay progresses a hole (cavity) forms, passes through the dentin, and once it reaches the nerve (pulp) it leads to pain and infection [1]. After a hole forms the tooth does not heal on its own, so finding decay at an early stage is the key to keeping treatment small [1].
DentStat analyzed 10,789 patient comments about cavities on YouTube dental content (4,581 of them questions). The most frequent questions were about choosing a filling material (1,457), the link to root canal treatment and crowns (852), and sensitivity after treatment (677) [4].
Does early decay need treatment right away?
At the surface demineralization (white spot) stage, fluoride application and good oral hygiene can remineralize the tooth and stop progression, so some dentists monitor it instead of drilling right away [1]. Arrested decay that has stopped progressing may also be monitored [1]. The line between monitoring and treating is based on the depth seen on X-rays and other exams, so asking for an explanation of the diagnosis helps with the decision [1].
How is the filling material chosen?
Even for the same cavity, the material depends on the depth and location of the decay, how much tooth remains, and the biting force on that tooth [1]. Small areas are finished with a filling such as resin, larger areas move up to an inlay made from an impression, and badly damaged or root-canal-treated teeth move up to a crown [1]. Material choice was the most common theme in the comment analysis (1,457), showing demand for explanations of the differences between materials and how to choose [4].
Which treatments does health insurance cover?
Amalgam and glass ionomer fillings are covered by National Health Insurance [2]. Light-cured composite resin is covered for cavity treatment in permanent teeth of children aged 12 and under [2]. Dental sealants (pit and fissure sealing), which fill the grooves on the chewing surfaces of molars to prevent cavities, are covered for first and second molars up to age 18 [2]. For adults, resin, inlays and crowns are mostly non-covered (not paid by Korea’s National Health Insurance) and prices vary by clinic. This guide does not cover individual clinics’ prices.
Why do cavities form between teeth even with careful brushing?
Toothbrush bristles cannot reach the contact surfaces where teeth touch, so plaque tends to remain there unless you use floss or interdental brushes [1]. Cavities between teeth (proximal caries) often progress without pain and are frequently found on X-rays, and in some cases both adjacent teeth are affected [1]. There were 453 related questions, with “why does this happen even though I brush” coming up repeatedly [4].
Is sensitivity after treatment normal?
After restoring a deep cavity close to the nerve, temporary sensitivity that gradually fades is not unusual [1]. However, if sensitivity gets worse over time, or throbbing pain occurs without any trigger (spontaneous pain), it is a sign that the condition of the nerve needs further evaluation [1]. Questions about sensitivity and pain after treatment numbered 677, the third most common theme [4].
What if different clinics give different diagnoses?
Whether to treat early or arrested decay now or to monitor it can depend on each dentist’s criteria, so clinics sometimes report a different number of cavities [4]. The comment analysis shows patients asking for an explanation of the diagnostic evidence, such as X-rays, and comparing diagnoses from more than one clinic when the decision is difficult [4]. Regional data on dental clinics across Korea, based on public data from the Health Insurance Review & Assessment Service (HIRA), is available on DentStat [3].
In-depth guides
Documents covering subtopics of Cavities in more depth.
- Proximal cavities and flossing: Early Detection and the Different Roles of Floss, Interdental Brushes and Water Flossers
- Pain and sensitivity after treatment: Normal Recovery and Signs to Get Rechecked
- Choosing a material: How Resin, Inlays, GI, Amalgam and Crowns Are Decided
- Overtreatment concerns: Why Clinics Find Different Numbers of Cavities and How to Check
- Root canals and crowns: When They Are Needed, Core Build-Ups and Saving the Tooth
- Cervical abrasion and sensitivity: Telling It Apart from Cavities, GI vs. Resin, and When to Monitor Without Drilling
- Monitoring early cavities: Treat vs. Watch, Remineralization and Cavities in Baby Teeth
- Acute toothache emergency: Painkiller Rules and Finding a Night or Holiday Dentist in Korea
- American-style resin debate: Extension for Prevention, Minimal Removal and How Materials Are Chosen
Frequently asked questions
- Can a cavity heal on its own?
- At the early stage, when the surface has turned white from demineralization, fluoride application and good oral hygiene can sometimes remineralize the tooth and stop progression. A cavity that has already formed a hole does not heal naturally and needs treatment.
- How do dentists decide between resin, an inlay and a crown?
- It depends on the depth and location of the decay, how much tooth remains, and whether the area takes heavy biting force. Small areas are usually filled (with resin or similar), larger areas get an inlay made from an impression, and a crown is considered when the tooth is badly damaged or after root canal treatment.
- Is any cavity treatment covered by health insurance in Korea?
- Amalgam and glass ionomer fillings are covered by National Health Insurance, and light-cured composite resin is covered for permanent teeth in children aged 12 and under. For adults, resin, inlays and crowns are mostly non-covered (not paid by National Health Insurance), so prices vary by clinic.
- I brush carefully, so why do I get cavities between my teeth?
- Toothbrush bristles cannot reach the contact surfaces where teeth touch, so plaque tends to stay there without floss or interdental brushes. Cavities between teeth often progress without pain and are commonly found during regular checkups and X-rays.
- My tooth is sensitive after a filling. Did something go wrong?
- After treating a deep cavity close to the nerve, temporary sensitivity that gradually fades is not unusual. However, if sensitivity keeps getting worse or you feel throbbing pain even at rest, further evaluation is needed, and you should return to the clinic that treated you.
- Why do different dentists find a different number of cavities?
- Dentists may use different criteria for whether to treat arrested or early decay now or to monitor it. Ask for an explanation of the diagnostic evidence, such as X-rays, and if it is hard to decide, some patients compare diagnoses from more than one clinic.
Find a dental clinic
Compare dental clinics by area and treatment in the area shortlists, or see nationwide figures in dental clinic statistics for South Korea.
Related topics
Root Canal TreatmentProsthetics: CrownsPediatric DentistryScaling
References
- National Health Information Portal: Dental Caries (Tooth Decay) · Korea Disease Control and Prevention Agency (KDCA)
- National Health Insurance Coverage Criteria for Cavity Treatment and Dental Sealants · Ministry of Health and Welfare · National Health Insurance Service (NHIS)
- Hospital Information Service Public Data · Health Insurance Review & Assessment Service (HIRA)
- Analysis of Patient Comments on YouTube Dental Content: 10,789 Cavity Comments (collected 2026-06-28) · DentStat (Osamil Inc.)
This content is general information based on public sources and does not replace diagnosis, prescription or treatment for any individual. If you have symptoms, consult a dentist.