What is a fissure sealant?

The chewing surface of a molar is not flat; it has narrow, deep grooves called “fissures”. Because these grooves can be narrower than a toothbrush bristle, they are hard to clean. This is why a large proportion of decay in children starts on these surfaces.

A fissure sealant is a thin protective resin that flows into these grooves and is hardened with a light. The grooves then become a shallow surface that is easy to clean. The treatment is not a filling; no healthy tooth tissue is removed.

How is a fissure sealant applied?

1. Examination: The tooth surface is examined carefully. Today, early signs of decay are classified by visually assessing the dried surface (using systems such as ICDAS) rather than pressing with a sharp probe; an X-ray is taken if needed.
2. Cleaning: The surface is cleared of plaque with a brush and paste.
3. Isolation: Cotton rolls or isolation devices are used to keep the tooth away from saliva. This step is the key to success.
4. Surface preparation: An acid gel is applied to the enamel briefly, then rinsed off and dried. This allows the resin to bond to the enamel at a microscopic level.
5. Application and curing: The sealant is flowed into the grooves and hardened with a light.
6. Check: The bite is checked; any excess is removed if necessary.

The procedure usually takes a few minutes per tooth and is comfortably tolerated by most children. Explaining the procedure to the child beforehand in short, simple language, showing them the instruments and a calm attitude from the parent all make cooperation easier. There is usually no special eating or drinking restriction afterwards; the child can return to normal eating the same day. The surface of the hardened sealant may feel slightly rough to the tongue in the first hours; this feeling soon disappears.

What is fluoride varnish and what does it do?

Fluoride makes enamel more resistant to acid attacks and helps early white spots to remineralise. Fluoride varnish is a sticky fluoride preparation; it is painted onto the teeth with a small brush, sets on contact with saliva and releases fluoride onto the surface for several hours.

Varnish applied in the clinic does not replace fluoride toothpaste used at home; it is additional protection. For children at high risk of decay, the dentist may recommend repeating it several times a year.

Fissure sealant or fluoride varnish?

Who is it suitable for, and at what age is it done?

Fissure sealants are most often applied to permanent molars as they start to come through. The first permanent molars usually erupt around age 6, and the second permanent molars around ages 11–13. If the grooves are deep and the child is at risk of decay, the treatment is planned once the tooth has erupted enough to be isolated. In risky situations, sealants can also be applied to baby molars and premolars.

The main factors that increase the risk of decay are:

• A history of decay or fillings
• Frequent sugary snacks and drinks spread throughout the day
• A regular brushing habit not yet established
• Use of an orthodontic appliance
• The presence of deep, narrow grooves

If there is newly started decay on the enamel surface that has not yet formed a cavity, sealing it can in some cases slow the progression of the lesion. If there is a clear cavity, a filling is needed. The dentist makes this distinction.

Why are check-up appointments important?

Fissure sealants and fluoride varnish should not be thought of as a one-off “vaccine”. A child’s mouth keeps changing: new teeth come through, eating habits change, orthodontic treatment may begin. That is why, at regular check-ups, the dentist assesses:

• whether the sealants are in place and intact,
• whether newly erupted teeth need sealants,
• whether there are early white spots or discolouration on the enamel surface,
• where support is needed with brushing and eating habits.

For a child at low risk of decay, check-ups can be less frequent; for a high-risk child, more frequent. A lesion caught early can often be monitored with preventive treatments without needing a filling, which helps keep the child’s experience of the dentist positive. If your family is spending an extended period in Istanbul, the check-ups can be planned around your stay.

A short checklist for parents

• Brushing twice a day, never skipping the bedtime brush
• Sugary foods and drinks limited to main meals
• No milk or fruit juice in a bottle at night
• A dental check-up when the first permanent molar starts to come through (around age 6)

How should fluoride be used at home?

The most important source of fluoride at home is toothpaste. The right amount for children varies with age: a smear the size of a grain of rice for young children, and a pea-sized amount for pre-school children, is enough. Brushing should be supervised by an adult, and the child should learn to spit out the toothpaste rather than swallow it. It is best to ask your child’s dentist which fluoride concentration of toothpaste to use.

What are the risks and what should you watch out for?

• Partial loss of the sealant: The most common problem is loss of adhesion due to saliva contamination during application, and it is usually noticed in the first months. That is why check-up appointments matter; if needed, the sealant is repaired or replaced.
• Decay being missed underneath: This risk is reduced by a good examination and, if needed, an X-ray; a sealant does not remove the need for regular check-ups.
• Allergy: If there is a known resin or acrylate allergy, be sure to tell the dentist.
• Too much fluoride: The varnish applied in the clinic is in a controlled amount. At home, it is important that toothpaste is not swallowed and that the recommended amount is not exceeded.

Frequently asked questions

Related pages

Medically reviewed by: Dr. Dt. Mehmet Fuat BozabaSpecialist in periodontology · September 2026

Appointments and information: message us on WhatsApp or call +90 544 289 66 33. Yayla Dental Akademi, Bahçelievler / Istanbul.

Sources: Pitts NB (ed.). Detection, Assessment, Diagnosis and Monitoring of Caries. Monographs in Oral Science, Vol. 21. Karger, 2009; Roberson TM, Heymann HO, Swift EJ (eds). Sturdevant’s Art and Science of Operative Dentistry, 4th ed. Mosby, 2002; Rai B, Kaur J. Fundamentals of Operative Dentistry. Jaypee Brothers Medical Publishers, 2010.

This article is for information only; diagnosis and treatment planning are determined solely by a doctor after an examination.