Baby (Primary) Tooth Cavity Treatment Guide: Why Treat Teeth That Will Fall Out, and How to Choose

Cavities in baby teeth need treatment too. All 20 baby teeth come in by age 2-2.5 and help with chewing and speech until they are replaced, while holding space for permanent teeth. In Korea, National Health Insurance coverage of light-cured composite resin applies only to permanent teeth at ages 5-12, so the out-of-pocket cost of baby-tooth cavity treatment can vary widely with the material and method.

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

Key facts

Number of baby teeth	20, all in by age 2-2.5 (source: Korea Disease Control and Prevention Agency (KDCA, 질병관리청))
When the primary dentition is complete	Around 30-41 months of age (why an oral checkup was added for this period) (source: Ministry of Health and Welfare)
Resin filling coverage eligibility	Cavities in permanent teeth without pulp lesions at ages 5-12 on the treatment date (baby teeth excluded) (source: Health Insurance Review and Assessment Service (HIRA, 건강보험심사평가원))
QLF cavity detection test	Coverage expansion approved for ages 15 and under, once every 3 months per mouth (December 2024) (source: Ministry of Health and Welfare)
Outpatient copayment, ages 1 to under 6	The standard copayment rate multiplied by 70% (source: Health Insurance Review and Assessment Service (HIRA))

Why treat baby teeth that will fall out anyway?

Baby teeth are replaced by permanent teeth one after another through the elementary school years, and baby molars fall out later than front teeth, so they stay in the mouth longer than you might expect. Meanwhile they chew food, shape speech, and keep the path and space for the permanent teeth growing beneath.

A baby-tooth cavity left alone can spread to the nerve, causing pain and pus at the gum, and long-lasting infection can affect the development of the permanent tooth below. If a baby tooth has to be pulled early, neighboring teeth can tilt into the gap and narrow the space for the permanent tooth, so a space maintainer may become necessary.

How can you spot a baby-tooth cavity at home?

The KDCA's infant checkup guidance advises looking for areas that are cloudy and opaque compared with other teeth, areas that have turned brown or black, and plaque left like a white film. Baby-tooth enamel is thinner than that of permanent teeth, so an early cavity can grow quickly, which makes finding these changes early important.

The backs of the front teeth, the grooves on the chewing surface of molars, and the spaces where teeth touch are places caregivers find hard to see. Have these areas checked at regular visits, and if teeth are touching, build the habit of using floss.

For a child who falls asleep with a bottle or breast at night, look especially closely at the backs of the upper front teeth and the edge of the gum. Saliva reaches this area less and milk or drinks linger there, so baby-tooth cavities start easily.

What are the treatment options for baby-tooth cavities?

The method is chosen by considering the depth of the cavity, how well the child cooperates, and how long the tooth will remain before it falls out. Even for a cavity of the same size, the recommendation can differ depending on whether the tooth will soon fall out or must serve for several more years.

Shallow cavities: remove the decayed part and fill it
Cavities near the nerve: treat part or all of the baby tooth's pulp, then fill
Badly broken-down molars: cover the whole tooth with a prefabricated crown
Teeth that cannot be saved: extraction, followed by a space maintainer if needed

What about baby-tooth treatment costs and insurance?

In Korea, insured resin filling covers cavities without pulp lesions in permanent teeth of children aged 5-12 on the treatment date, and baby teeth are not included. Resin on a baby tooth is therefore non-covered and its price differs by clinic, and when other filling materials or crowns are used, you need to check coverage for each one.

The QLF cavity detection test, which finds cavities early, had been covered once every 6 months for ages 5-12, and in December 2024 the Ministry of Health and Welfare decided to widen this to ages 15 and under, once every 3 months. For children aged 1 to under 6, the copayment on insured care is lowered to about 70% of the standard patient rate.

How can you keep a treated baby tooth from decaying again?

The edges of a treated baby tooth and the neighboring teeth are prone to new cavities, so it helps to set a regular checkup interval with your dentist. From 42-53 months, brush twice a day with a pea-sized amount of children's fluoride toothpaste, and until age 7 a caregiver should finish the brushing.

Falling asleep with a bottle and sipping sweet drinks throughout the day are typical factors that make baby-tooth cavities recur. When the first permanent teeth begin to erupt around 54-65 months, discuss molar sealants and fluoride application.

Common myths and facts

Myth: Baby teeth fall out soon, so cavities can be left alone.

Baby teeth handle chewing and space-keeping until permanent teeth arrive. If a cavity reaches the nerve or the tooth is lost early, it can lead to pain, pus and a shortage of space for the permanent tooth.

Myth: Resin treatment for children's cavities is covered by National Health Insurance regardless of age.

Under HIRA criteria, insured resin filling covers only cavities in permanent teeth at ages 5-12. Resin on baby teeth is not covered.

Myth: A baby-tooth cavity does not progress if it does not hurt.

Early cavities often progress without pain. If you see cloudy or brown areas, it is better to have a checkup even when it does not hurt.

Frequently asked questions

Does nerve treatment on a baby tooth cause problems for the permanent tooth?

Nerve treatment on a baby tooth aims to calm the infection so the tooth can be kept until its natural time. After treatment, the position and development of the permanent tooth below continue to be checked with X-rays at regular visits.

Isn't a silver crown on a baby tooth unsightly?

For badly broken-down baby molars, metal prefabricated crowns are often used, and for front teeth or visible spots you can discuss other materials. Cost and coverage differ by material, so ask for the options to be explained.

Can several cavities be treated in one visit?

Depending on the child's cooperation and the number of cavities, treatment may be split over several visits or sedation may be considered. Whether to do it all at once or in parts is decided with the dentist based on the child's condition and safety. When split, it is usual to start with painful or deep cavities.

If a baby tooth is loose and also has a cavity, is it treated?

If a permanent tooth is about to come in and the baby tooth is naturally loosening, the dentist may watch it or pull it instead of treating it. The decision is made after checking the position of the permanent tooth on an X-ray.

Can my child eat right after baby-tooth treatment?

If anesthesia was used, the child may bite the cheek or lip before feeling returns, so eating is postponed. After the time advised for the filling material has passed, start with soft foods.

References

Korean version →