Fissure sealants are a protective layer used to seal deep pits or grooves in teeth, to help reduce dental decay.
Fissure sealant is most commonly recommend to cover the grooves and pits of the back molars, as these are the most common locations for cavities in the teeth.
Pits and fissures on the surface of the tooth are often hard to clean due to the grooves being quite deep and narrow, therefore they tend to harbour plaque, food and bacteria. This area of plaque and bacteria is often very difficult to clean, as the bristles on your toothbrush are often not able to get to the deepest part of these grooves. If the grooves are not cleaned properly, decay will start on the top of the tooth, and the tooth may end up requiring a filling.
Your dentist might advise you to have fissure sealants if you have large grooves or pits in your teeth that cannot be easily cleaned with a toothbrush.