This is general information for parents, not a diagnosis. Which preventive treatments suit your child is decided at a dental examination.
Quick Answer
Fissure sealants are a thin, tooth-coloured or clear coating painted onto the biting surfaces of back teeth, usually the permanent molars soon after they come through, around age 6 and again around age 12. They seal the deep grooves, or fissures, where food and bacteria collect and where decay in children most often starts. Fluoride varnish is a concentrated fluoride coating painted onto the teeth that helps enamel resist acid and can help early decay remineralise. UK public health guidance recommends fluoride varnish for children from age 3 at least twice a year, and more often for children at higher risk. Both are quick, need no drilling or injections, and work best alongside brushing twice a day with fluoride toothpaste and limiting sugar.
Key Takeaways
- Sealants protect the grooves of back teeth; fluoride varnish protects all tooth surfaces.
- Both take only minutes and need no drilling or injections.
- Sealants are usually placed on permanent molars soon after they erupt.
- Fluoride varnish is commonly applied at least twice a year, more often for higher-risk children.
- Neither replaces brushing, a sensible diet and regular check-ups.
Fissure Sealants
What they are. A flowable resin material bonded into the grooves of the chewing surfaces of back teeth.
How they are applied.
- The tooth is cleaned and dried.
- A conditioning solution is applied briefly, then rinsed off.
- The sealant is painted into the grooves and hardened, often with a light.
- The bite is checked.
Who benefits most. Children with deep grooves, children who have had decay in other teeth, and permanent molars that have recently come through, when the enamel is newest and most vulnerable.
How long they last. Sealants can last several years but can wear or chip, so they are checked at regular visits and repaired if needed.
Fluoride Varnish
What it is. A sticky, concentrated fluoride coating painted onto the teeth with a small brush. It sets on contact with saliva.
What it does. Fluoride helps minerals return to enamel and makes enamel more resistant to acid. See can a cavity heal.
After it is applied. Your child may be advised to avoid hard food and hot drinks for a few hours and not to brush until the evening or the next morning, so the varnish stays in contact with the teeth. Follow the instructions given.
Side by Side
| Fissure sealant | Fluoride varnish | |
|---|---|---|
| Protects | Grooves on chewing surfaces of back teeth | All tooth surfaces |
| How | Physical seal over the grooves | Strengthens enamel chemically |
| Typical timing | Soon after permanent molars erupt | At least twice a year from age 3; more for higher risk |
| Drilling or injections | No | No |
| Lasts | Several years with checks | Repeated at intervals |
What They Do Not Replace
- Brushing twice a day with fluoride toothpaste, spitting rather than rinsing
- Keeping sugary food and drinks to mealtimes
- Regular check-ups, where decay can be caught early
See cavities in baby teeth and your child's first dental visit.
Are They Safe?
Fluoride varnish is applied in small amounts by a dental professional and has been widely used in public health programmes. Sealants are placed on the tooth surface and do not require removing healthy tooth. If you have questions about the materials, ask the dentist, who can tell you what is being used.
At Adil Dent Clinics
Children's care at the clinic includes check-ups, fluoride varnish and fissure sealants, with X-rays taken only when clinically needed and parents staying with their child. See the pediatric dentistry page.
Conclusion
Sealants and fluoride varnish are among the easiest ways to keep a child's teeth free of decay. They take minutes, do not hurt, and work best alongside good habits at home.
Ask on WhatsApp or request an appointment.