Fluoride Application Guide: Professional Application Frequency, Gel vs Varnish, Aftercare Precautions and Cost
Fluoride application is a procedure in which a dentist or dental hygienist applies high-concentration fluoride to the teeth to prevent cavities and to halt the progress of early cavities that have already formed. The KDCA National Health Information Portal recommends repeating it every 3 to 6 months, and at least twice a year for children and adolescents aged 3 and over and adults at risk of cavities. In Korea, fluoride application for cavity prevention is not covered by health insurance, so the cost differs by dental clinic.
Key facts
| Professional application interval | Repeat every 3 to 6 months; the actual interval is set by the dentist according to cavity risk (source: Korea Disease Control and Prevention Agency (KDCA, 질병관리청) National Health Information Portal) |
|---|---|
| Who is advised at least twice a year | Children and adolescents aged 3 and over, and adults at risk of developing cavities (source: Korea Disease Control and Prevention Agency (KDCA, 질병관리청) National Health Information Portal) |
| No eating or rinsing after application | 30 minutes for fluoride gel, 1 hour for fluoride varnish (source: Korea Disease Control and Prevention Agency (KDCA, 질병관리청) National Health Information Portal) |
| Amount of fluoride toothpaste | Rice-grain size under age 3, pea size ages 3 to 6, pea size or more after age 6 (source: Korea Disease Control and Prevention Agency (KDCA, 질병관리청) National Health Information Portal) |
| Fluoride mouth rinse | 0.05% sodium fluoride solution once a day, about 10 ml for 1 minute for adults, about 5 ml for ages 6 and under (source: Korea Disease Control and Prevention Agency (KDCA, 질병관리청) National Health Information Portal) |
| Health insurance | Topical fluoride application for cavity prevention is uninsured (source: National Health Insurance Service (NHIS, 국민건강보험공단)) |
How does fluoride application prevent cavities?
According to the National Health Information Portal, fluoride ions enter the enamel and stabilize its crystal structure, making it better able to withstand the acid made by cavity-causing bacteria. Plaque and saliva store fluoride and slowly release it in the mouth, and it also interferes with the gathering and growth of cavity-causing bacteria.
The period when the effect is greatest is guided as from when baby teeth first begin to erupt until about 2 years after the last permanent tooth comes in, roughly up to ages 14 to 15. However, it also helps people at high cavity risk, such as adults with reduced saliva or receded gums that expose the roots.
How do fluoride gel and fluoride varnish differ?
Fluoride gel is placed in a tray shaped like the dental arches and held with the upper and lower teeth biting together, or applied with a cotton swab. Because it does not run, it has the advantage of staying in contact with the teeth longer.
Fluoride varnish is applied thinly with a dedicated brush after the teeth are dried, forming a film that releases fluoride for a long time. It is also easy to apply when holding a tray in the mouth for long is difficult. Which method is used is decided by age, cooperation and cavity risk.
- Fluoride gel: applied with a tray or swab, no food for 30 minutes afterward
- Fluoride varnish: painted on thinly, no food for 1 hour afterward
- Brushing after varnish: gently after 4 hours
- Saliva that pools during application: spit it out instead of swallowing
What should you observe after application?
After fluoride gel, do not rinse with water or eat for 30 minutes, and after fluoride varnish, do not rinse or eat for 1 hour. On the day varnish is applied, the National Health Information Portal advises brushing gently after 4 hours, using a toothbrush you no longer use to avoid damaging the bristles.
Swallowing too much fluoride can cause nausea or vomiting. In that case, have the person vomit or give calcium-containing food such as milk to reduce absorption, and consult a dentist or medical institution. Taking in too much fluoride in infancy, before the permanent teeth come in, can rarely cause dental fluorosis, spots on the teeth, so a parent must manage the amount of a child's toothpaste.
How is fluoride used at home?
The National Health Information Portal recommends fluoride toothpaste even for children under 2 and guides the amount as rice-grain size under age 3, pea size ages 3 to 6, and pea size or more after age 6. If a child aged 6 or under cannot spit out toothpaste well, a parent adjusts the amount.
For fluoride mouth rinse, hold a 0.05% sodium fluoride solution once a day, about 10 ml for adults for 1 minute, then spit it out. For ages 6 and under there is a risk of swallowing, so use about 5 ml under a parent's supervision, and after using the rinse, do not rinse with water and do not eat for 30 minutes.
Who should be more careful to get fluoride application?
People who have recently had cavity treatment several times, wear braces, or often drink sweet beverages have a high cavity risk, so regular professional fluoride application helps. People whose mouths are dry from medication or aging, and those whose gums have receded and exposed soft root surfaces, are also worth consulting.
Children often receive fluoride application at regular checkups once their baby teeth begin to come in, and when molars are newly erupting it is planned together with sealants. The National Health Information Portal says the actual application interval is set by the dentist according to individual cavity risk, so it helps to confirm the next application time at each checkup.
Common myths and facts
Myth: Fluoride application is a treatment only for children.
The National Health Information Portal recommends fluoride application at least twice a year for adults at risk of cavities as well. People whose gums have receded and exposed the roots can also be candidates.
Myth: If you apply fluoride, you can brush less.
Fluoride only makes teeth stronger against acid and does not remove plaque. Removing plaque with brushing and floss comes first.
Frequently asked questions
Is fluoride application covered by health insurance?
Under the non-covered standard announced by the National Health Insurance Service, care for cavity prevention such as topical fluoride application is not covered by health insurance. The cost differs by dental clinic, so ask in advance.
How often should I get fluoride applied?
The National Health Information Portal recommends repeating professional application every 3 to 6 months. The dentist decides according to personal risk, such as a shorter interval for people who often get cavities and a longer one for those at lower risk.
Can I drink water right after fluoride is applied?
It is best not to rinse or eat for 30 minutes after fluoride gel and 1 hour after fluoride varnish. That lets the fluoride stay on the teeth long enough to work.
Isn't fluoride harmful to the body?
The National Health Information Portal explains that if the procedure is inaccurate and a lot of fluoride is swallowed, acute symptoms such as nausea or vomiting can occur. That is why pooled saliva is spat out during application and parents watch the amount of toothpaste and rinse a child uses.
I have sealants. Do I still need fluoride application?
A sealant protects only the grooves on the chewing surface, while fluoride hardens the whole tooth surface. The two methods complement each other, so people at cavity risk often get both.
Related topics
- Cavities and Root Canal Treatment
- Cavity Prevention
- Children's Fluoride Application
- Sealants
- Stages of Tooth Decay