Fissure Sealant
In this section, we will cover:
- What is a fissure sealant?
- Why do I need it?
- What does the procedure involve?
- How long will it last?
What is a fissure sealant?
Fissure sealants are protective coatings that are painted onto the pits and grooves of your back teeth. They are sometimes used on front teeth if you have deep pits in the back surface.
The most commonly used material is a plastic resin sealant - these can be clear or white. Resin sealants are always the first choice as they tend to last longer. If it isn't possible to keep the area dry, your dentist may place a glass ionomer sealant which comes in different colours.
Why do I need it?
Fissure sealants are used to protect teeth from decay so you're less likely to need a filling or tooth extraction.
If you're at a high risk of tooth decay, your dentist will suggest placing fissure sealants on your back teeth. They stop food and bacteria getting trapped in the grooves of the teeth, making them easier to clean. You can find out more about tooth decay and how it's caused here.
In some cases, fissure sealants are used to "seal in" early decay. This could be decay confined to the enamel (outer layer of the tooth) or decay which has just begin to spread into the dentine (middle layer of the tooth). The aim is to "starve" the bacteria and prevent the decay from spreading further into the tooth. These need to be carefully monitored with xrays.
Studies show children who have fissure sealants placed on their teeth are significantly less likely to develop tooth decay. Fluoride varnish is another effective method at preventing tooth decay - you can find out more about it here. More research is being done to find out whether fissure sealants are better at preventing decay in back teeth than fluoride varnish.
What does the procedure involve?
Resin Fissure Sealants
Placing resin fissure sealants is a very simple procedure which does not require any local anaesthetic (numbing injection). It only takes a few minutes but you will have to keep your mouth open the whole time so the tooth stays dry. This helps the sealant to "stick" to the tooth.
Your dentist will keep your tongue/cheeks out of the way with cotton rolls, dental mirrors and suction (a small hoover used to get rid of any saliva and water).
First, the tooth will be cleaned to remove any food or bacteria. A blue/green gel (phosphoric acid) is then scrubbed onto the tooth with a small brush then washed off with lots of water and dried. You might find the gel has a funny taste but your dentist will try to avoid it getting onto your tongue. After this, a bonding liquid is sometimes brushed onto the tooth which acts as a type of "glue". A special blue light is shone on the tooth for 10 seconds to help the liquid harden. This prepares the enamel (outer layer of the tooth) to strengthen the bond with the sealant.
The sealant is then applied to the tooth with a small brush or dental probe and the blue light is used again to let this harden and stick to the tooth. Your dentist will run a probe along the sealant to make sure all the edges are smooth. If there are any ledges or steps, your dentist will either top up the sealant or remove it and start again. If ledges or steps are left as they are, they increase the risk of tooth decay as food/bacteria can get trapped and this is difficult to clean.
Glass ionomer sealants
Glass ionomer sealants are even easier to place than resin sealants. Unlike resin sealants, glass ionomer sealants will stick to the tooth even if the area isn't kept completely dry. This makes it a good option for children with limited cooperation in the dentist's chair.
The sealant comes in a capsule which is mixed in a special machine (this part is quite loud!). Once the sealant is mixed, a small amount is squirted onto the tooth - for some children who can't tolerate much at the dentist, the sealant can be applied to the tooth with a finger. This takes a couple of minutes to harden - this process can be sped up using the blue light as it heats up the sealant. A small amount of petroleum jelly is smeared over the tooth and that's it!
How long will it last?
On average, a resin fissure sealant will last about 2 years - some may even last longer but some may come off within 6 months. It largely depends on how well they were placed and how dry the tooth was during the procedure. Glass ionomer sealants are weaker so they do not last as long - this is why they are not usually the first choice.
If the sealant chips or debonds (unsticks) from the tooth, decay can begin to form. This decay can continue to spread unnoticed until it forms a large hole in your tooth! It's important you go for regular check ups at the dentist so they can monitor the sealants for potential problems.
Fissure sealants do not always need to be replaced but if your dentist still considers you to be at high risk of decay, they may suggest replacing them.