Key facts
- Early cavities often cause no symptoms and are found by exam and X-ray.
- Decay that reaches the pulp may need root canal treatment or extraction.
- Korean NHIS typically covers basic fillings for enrolled patients (amalgam, and resin in some cases).
What is a cavity?
A cavity is an area of tooth decay that has broken down the hard outer layers of a tooth and formed a small hole. It starts when bacteria in plaque feed on sugars and starches and produce acid that dissolves enamel.
Mayo Clinic describes decay moving in stages: plaque forms, acid wears through the enamel, and the damage then spreads into the softer dentin and, if left alone, into the pulp, where it can cause a serious toothache, infection and tooth loss ( Mayo Clinic).
How do I know if I have a cavity?
Early cavities often cause no symptoms, which is why they are usually found at check-ups. As decay grows, you may notice sensitivity to sweets, hot or cold, pain when biting, a visible hole or pit, or brown, black or chalky white spots.
Some sensitivity has other causes, such as gum recession or worn enamel. Our guide to sensitive teeth treatment covers those. If you are already in pain while traveling, read what to do about a toothache in Korea.
How are cavities treated?
Treatment depends on how deep the decay has gone. The earlier it is caught, the smaller and simpler the repair.
| Stage of decay | Typical treatment | Fee at Lucid |
|---|---|---|
| Early enamel spot, no hole yet | Fluoride, better cleaning and monitoring | Discussed at your exam |
| Small to medium cavity | Tooth-colored resin (composite) filling | Quoted after an exam |
| Larger cavity on a back tooth | Lab-made inlay | Quoted after an exam |
| Decay that has weakened the tooth walls | Crown | Quoted after an exam |
| Decay that has reached the nerve | Root canal, then a crown or filling | Quoted after an exam |
These are non-covered fees, confirmed after an exam. Patients enrolled in Korea's national health insurance may have some fillings covered (amalgam, and resin in some cases); confirm your coverage. Compare with other treatments on our guide to dental fees in Seoul.
What happens when a cavity is treated?
A standard cavity repair is usually completed in a single visit. Here is what to expect.
- Exam and X-ray: the dentist checks the tooth visually and with X-rays, which show decay between teeth that cannot be seen directly.
- Plan: you are told how deep the decay looks, which material is suggested and the fee before work begins.
- Numbing: local anesthesia is given if the cavity is more than very shallow.
- Removing decay: softened, decayed tooth is cleaned out, keeping as much healthy tooth as possible.
- Repair: the space is filled with resin and hardened with a curing light, or scanned for an inlay if it is large.
- Bite check and polish: the filling is shaped so your teeth meet evenly.
For details on materials, see our page on dental fillings in Seoul.
What happens if a cavity is left untreated?
Decay does not heal by itself once it has formed a hole. Left alone, it usually grows, and a tooth that needed a small filling may later need a root canal, a crown or extraction.
Once bacteria reach the pulp, the nerve can become inflamed or infected, sometimes with a painful abscess. At that stage, root canal treatment or removal of the tooth is usually needed. That is why it is worth having a cavity checked even if it does not hurt.
Can I get a cavity fixed during a short trip?
Yes, usually. A resin filling can often be placed at the same appointment as the exam if time allows, which makes it practical even on a short stay.
Inlays need lab time and usually a second visit some days later. If the tooth turns out to need a root canal, the plan becomes longer. Tell us your travel dates when you book so the dentist can prioritize what matters most before you leave.
How can I prevent new cavities?
Prevention is mostly daily habits plus regular professional care. Mayo Clinic's advice includes brushing with fluoride toothpaste, cleaning between teeth, limiting frequent snacking and sugary drinks, and seeing a dentist regularly.
- Brush twice a day with fluoride toothpaste, and clean between your teeth daily.
- Limit sipping sweet coffee drinks, juice or soda throughout the day; frequency matters as much as quantity.
- Drink water after meals and snacks, especially when traveling.
- Ask about sealants for deep grooves in back teeth.
- Keep up regular cleanings; see our guide to teeth cleaning and scaling in Seoul.
Can decay form under old fillings and crowns?
Yes. Decay that starts at the edge of an existing filling or crown is called recurrent or secondary decay, and it is a common reason older dental work needs replacing.
Tiny gaps can open at the margin as fillings wear or as gums recede, letting plaque collect where a toothbrush struggles to reach. These cavities can be hard to see, so X-rays and a careful look around each restoration are part of a thorough exam. If a crown or filling has already come out, see our guide on a lost crown or filling in Seoul.
Who is more likely to get cavities?
Anyone can get cavities, but risk is higher with frequent sugary or acidic food and drink, dry mouth (from medicines or dehydration), old or worn fillings, gum recession that exposes roots, acid reflux, and braces or other appliances that trap plaque. Very young children and older adults also tend to be at higher risk. If you are prone to decay, your dentist may suggest shorter gaps between check-ups.
What are the risks of treatment?
Most fillings are straightforward. Possible after-effects include temporary sensitivity to cold or biting, a filling that feels high until adjusted, and, with deep cavities, a nerve that becomes inflamed later and needs root canal treatment. Individual results vary; a consultation and exam are required.
Book a consultation
Noticed a dark spot, a rough edge or a twinge when you drink something cold? Send a photo on WhatsApp at +82-10-8354-2975, or book a check-up and cavity treatment. Lucid Dental is in front of Exit 3, Eonju Station, open until 20:30 Tuesday to Thursday.
Frequently asked questions
Can a cavity go away by itself?
A very early white-spot lesion in enamel can sometimes harden again with fluoride and better cleaning. Once a hole has formed, the tooth cannot rebuild itself, and the decayed area needs to be removed and repaired.
Why do I have cavities when I brush every day?
Brushing misses the spaces between teeth, so cavities often start there. Frequent snacking, sweet drinks, dry mouth and deep grooves in back teeth also raise risk even with good brushing.
Can you treat several cavities in one appointment?
Often, yes, especially when they are on the same side of the mouth and can be numbed together. The dentist may split treatment into more than one visit if there are many teeth or deep cavities.
Is cavity treatment safe right before a flight?
A routine resin filling is usually fine before flying. If a cavity is deep, the tooth may be sensitive for a few days, so try not to leave treatment until the very last day.
Do children's baby teeth with cavities need treatment?
Usually, yes, because decay in baby teeth can cause pain and infection and affect the adult teeth underneath. The approach depends on the child's age and how long the tooth will stay, and is decided after an exam.