Fissure sealants are thin, protective coatings painted onto the chewing surfaces of back teeth to seal off the deep grooves where decay often starts. They are quick to place, usually need no needles or drilling, and are most often recommended for children’s newly erupted adult molars when those teeth are at higher risk of decay. Not every child needs them; the decision depends on the shape of the teeth and the child’s individual decay risk.
What are fissure sealants?
The chewing surfaces of molars and some premolars have natural pits and grooves, called fissures. In some teeth these fissures are deep and narrow, sometimes narrower than a single toothbrush bristle. Plaque and food get trapped there, and even a careful brusher can’t clean them properly.
A fissure sealant is a flowable material, usually a resin or a glass ionomer, that flows into those grooves and hardens. It creates a smoother surface that is easier to keep clean and physically blocks bacteria from settling into the deepest parts of the fissure.
Resin vs glass ionomer sealants
- Resin sealants are the most common. They bond well to enamel and tend to last longer, but they need a dry tooth to bond, which can be tricky on a tooth that is still erupting.
- Glass ionomer sealants are more tolerant of moisture and release a small amount of fluoride. They are sometimes used as a temporary measure on partly erupted teeth or in young children who find it hard to sit still, and may be replaced with a resin sealant later.
Which teeth are usually sealed, and when?
Sealants are most often placed on permanent (adult) molars soon after they come through, because a newly erupted tooth’s enamel is still maturing and is more vulnerable to decay in its first few years.
- First permanent molars usually erupt around age six, behind the baby teeth.
- Second permanent molars usually erupt around age 12.
- Premolars with deep grooves are sometimes sealed too.
- Baby molars are occasionally sealed in children who are at high risk of decay.
Adults can have sealants as well if they have deep, decay-free fissures and a higher risk of decay, though this is less common.
Who needs fissure sealants?
Australian dental guidance takes a risk-based approach, meaning sealants are recommended where they are likely to help rather than for every child automatically. Your dentist will consider:
- The shape of the fissures. Deep, narrow grooves that trap plaque are more likely to benefit than shallow, open ones.
- Your child’s decay history. Children who have already had decay in baby teeth are at higher risk in their adult teeth.
- Diet. Frequent snacking or sugary drinks raise decay risk.
- Oral hygiene. Children who find brushing back teeth difficult may benefit more.
- Medical or developmental factors. Conditions that make brushing harder, reduce saliva or affect enamel can increase risk.
- Early signs on the tooth. Very early changes in the enamel of a fissure, before a cavity forms, may be sealed to help stop progression.
If a tooth has shallow grooves and a child’s risk is low, your dentist may recommend simply monitoring it with good brushing and fluoride toothpaste.
How sealants are placed
Placing a sealant is usually one of the easiest dental procedures for a child. It takes a few minutes per tooth, and in most cases no local anaesthetic or drilling is needed.
- Cleaning. The tooth surface is cleaned to remove plaque and debris.
- Preparing the surface. For resin sealants, a mild conditioning gel is applied briefly and rinsed off. This roughens the enamel microscopically so the sealant can grip.
- Keeping it dry. Cotton rolls or a small suction tip keep saliva away. This is the step that matters most for a sealant to stay on.
- Applying the sealant. The liquid material is painted into the fissures.
- Setting. A blue curing light hardens resin sealants in a few seconds.
- Checking the bite. The dentist checks that the sealant isn’t too high and that it has covered the grooves.
Your child can eat and drink normally straight afterwards. Some children notice the tooth feels a little different for a day or so until they get used to it.
How well do fissure sealants work?
There is good evidence that resin sealants reduce decay on the chewing surfaces of permanent molars in children compared with no sealant, particularly in children at higher risk. They only protect the grooves on the chewing surface, though. They don’t protect the smooth sides of the teeth or the areas between teeth, where decay can still develop.
So sealants work alongside, not instead of, the basics: brushing twice a day with fluoride toothpaste, limiting sugary food and drinks, and regular check-ups.
How long sealants last and their limitations
Sealants can last several years, and many stay in place throughout childhood and the teenage years. Over time they can wear, chip or come away partly or completely. A partly lost sealant can sometimes trap plaque at its edge, so it’s important they are checked at each visit and topped up or replaced when needed.
Other points to know:
- A sealant may not stay on well if the tooth couldn’t be kept dry, which is more likely on a partly erupted tooth.
- Sealants are not placed over a cavity. If decay has already formed, the tooth may need a filling instead.
- Some parents ask about BPA in resin sealants. Studies have found any exposure from placing a sealant is very low and short-lived, and sealants remain widely recommended in dentistry. If you have concerns, discuss the materials with your dentist.
- As with any treatment, results vary, and whether sealants are suitable depends on assessment.
Helping your child keep their teeth healthy
- Help with brushing until your child can do it well on their own, often until around age eight. Pay special attention to the back molars.
- Use a pea-sized amount of fluoride toothpaste: a low-fluoride children’s toothpaste from 18 months to five years, and a standard fluoride toothpaste from age six, unless your dentist advises otherwise.
- Make water the main drink and keep sweet snacks to mealtimes.
- Bring your child for regular check-ups so new molars can be assessed as they come through.
You can read more about our approach to children’s dentistry, and how sealants fit into wider preventive dentistry for the whole family.
When to see a dentist
It’s a good idea to book a check-up around the time your child’s first adult molars come through, usually about age six, and again around age 12 for the second molars. See your dentist sooner if you notice dark spots or staining in the grooves of a back tooth, if your child complains of sensitivity or pain when eating, or if an existing sealant feels rough or looks like it has come away. At our Macquarie Park practice we’ll check your child’s teeth and explain whether sealants would be useful for them.
Frequently asked questions
Do fissure sealants hurt?
Placing a sealant is usually comfortable for children. The tooth is cleaned, prepared and painted, and in most cases no needles or drilling are needed. Most children find it one of the easiest dental visits.
At what age should my child get fissure sealants?
Sealants are most often placed soon after the first permanent molars erupt, around age six, and the second permanent molars, around age 12. Your dentist will assess whether each tooth would benefit.
How long do fissure sealants last?
Sealants can last several years, and many stay in place throughout childhood. They can wear or chip over time, so your dentist will check them at each visit and repair or replace them if needed.
Can adults get fissure sealants?
Yes, sometimes. Adults with deep, decay-free grooves and a higher risk of decay may benefit. It is less common than in children, and your dentist will advise whether it’s worthwhile.
Do sealants replace brushing?
No. Sealants protect only the grooves on the chewing surfaces. Brushing twice a day with fluoride toothpaste, cleaning between teeth and limiting sugar are still essential.
If your child’s adult molars are coming through, a check-up is a good time to ask about sealants. Call North Ryde Dentistry on (02) 8090 1102 or book an appointment.
This article is general information only and is not a substitute for advice from your own dentist. Any treatment carries risks; your dentist will discuss whether it is suitable for you.
Related at North Ryde Dentistry: our North Ryde dental clinic