Sealant (Pit and Fissure Sealing) Guide: Health Insurance Rules Up to Age 18, the Best Time, Loss of the Sealant and Care

A sealant is a preventive procedure that fills the narrow, deep grooves on the chewing surfaces of molars with a flowable material so food and bacteria cannot lodge in them; it is also called pit and fissure sealing. In Korea, cavity-free first and second large molars up to age 18 are covered by health insurance with a 10% copay. The best time is right after the molars come in, and you need to check at regular checkups that the sealant has not come off.

Published 2026-11-08 · Updated 2026-11-08 · DentalStatics editorial team

Key facts

Health insurance eligibility	Up to age 18, first and second large molars that are sound teeth with no cavity (source: National Health Insurance Service (NHIS, 국민건강보험공단))
Number of eligible teeth and copay	A total of 8 teeth, 10% copay (source: National Health Insurance Service (NHIS, 국민건강보험공단))
Other cases	Pit and fissure sealing for cavity prevention is in principle uninsured (source: National Health Insurance Service (NHIS, 국민건강보험공단))
Best time to get it	Elementary and middle school years when molars come in; right away once a regular checkup confirms the molars have erupted (source: Korea Disease Control and Prevention Agency (KDCA, 질병관리청) National Health Information Portal)
Material	One of the preventive procedures using composite resin-type materials (source: Korea Disease Control and Prevention Agency (KDCA, 질병관리청) National Health Information Portal)

How does a sealant prevent cavities?

The chewing surfaces of molars have deep grooves narrower than toothbrush bristles, so food and plaque lodge easily and are hard to clean. A sealant fills these grooves in advance to make the surface smooth and remove places where bacteria can stay.

Fluoride works well on smooth tooth surfaces but is relatively less effective in narrow, deep grooves. So using fluoride application and a sealant together can make up for each other's weak spots. The KDCA National Health Information Portal introduces cavity prevention through pit and fissure sealing as one use of composite resin.

In which cases does health insurance apply?

Under the non-covered standard announced by the National Health Insurance Service, pit and fissure sealing for cavity prevention is in principle uninsured. As an exception, first and second large molars that are sound teeth without cavities in people aged 18 or younger are covered.

The NHIS webzine states that the eligible teeth total 8, upper and lower, left and right, with a 10% copay. Teeth that already have cavities or fillings, premolars and third large molars are not covered, and sealants received by adults are also uninsured.

Age: up to 18
Teeth: first large molars and second large molars
Condition: sound teeth without cavities
Copay: 10%

When is the best time to get one?

The National Health Information Portal explains that cavities form easily in the elementary and middle school years when molars come in, and recommends having it done right away once a regular checkup confirms that the molars have erupted. Newly erupted molars have surfaces that are not yet fully hardened and are hard to reach with a toothbrush, so they are vulnerable to cavities.

First and second large molars come in at different times, so it is often impossible to get them all done at once. As the child grows, keep up regular checkups and check each time a new molar comes in whether a sealant is needed.

What is the procedure, and how is it cared for afterward?

In most cases it is done without grinding the tooth or anesthesia. The grooves are cleaned, the surface is treated with a chemical and dried so no moisture touches it, the flowable material is applied to the grooves, and then hardened with light. It does not stick well if saliva touches it, so keeping the tooth dry decides success or failure.

A sealant can wear down or partly come off under chewing force. If food lodges in a gap where it has come off, cavities can actually form, so at regular checkups check whether it remains and refill it if necessary. Even with a sealant, the spaces between teeth and the gum side are not protected, so brushing and flossing must continue.

How are sealants used together with other prevention methods?

A sealant protects only the grooves on the chewing surface, so to protect the whole tooth it must be combined with other methods. The National Health Information Portal recommends brushing at least twice a day with fluoride toothpaste, always brushing before bed, and using floss once teeth have come in.

Children at high cavity risk are best given professional fluoride application at checkups and fewer sweet snacks and drinks. If the next checkup is scheduled on the day the sealant is placed, any part that has come off can be found in good time.

Common myths and facts

Myth: With a sealant, that molar will never get cavities for life.

A sealant reduces cavities in the chewing surface grooves but cannot prevent cavities between teeth or on the gum side, and it can come off. Its condition must be checked at regular checkups.

Myth: Even with a small cavity, you can just put a sealant over it.

Covering an unseen cavity with a sealant lets the cavity progress inside. Health insurance also covers only sound large molars without cavities, and if there is a cavity, treatment comes first.

Frequently asked questions

Does a sealant hurt?

In most cases the tooth is not ground or anesthetized; the material is applied to the surface and hardened, so it does not hurt. Even where part of the groove has to be lightly shaped, the pain is not great.

Can sealants be placed on baby molars too?

They can, but the health insurance applies to the permanent first and second large molars. Sealants on baby molars are uninsured, so the need and cost are decided by consulting the dentist.

Is insurance applied when a lost sealant is refilled?

Whether refilling is recognized for coverage can differ with timing and tooth condition, so it is most accurate to check with the dental clinic that did the procedure. If you find a spot where the sealant has come out, have it checked quickly, before a cavity forms in that groove.

Can adults not get sealants after age 18?

You can get them, but health insurance does not apply. Adults choose by weighing cost and effect when the grooves are deep and cavity risk is high.

When can I eat after a sealant?

If a material that hardens immediately with light is used, you can often eat right after the procedure. However, the material and accompanying treatment can differ by dental clinic, so follow the instructions given after the procedure.

References

Korean version →