Brushing your teeth everyday is great, but even the best oral hygiene habits can produce wear on the teeth and produce cavities. Dental sealants are a made of plastic materials that are applied to the back teeth in order to prevent cavities and nooks or crannies forming. This strong material is used to resist bacteria and acids, as well as provide a barrier to destructive food particles. Food and plaque are essentially 'sealed out' of the areas of your back teeth. When the sealants are applied correctly they are nearly 100% effective in preventing dental caries.
Sealants are usually applied at a dentist's office. Teeth are first cleaned and dried before a thin layer of plastic liquid is painted over the nooks and crannies of the back teeth. After the plastic liquid is applied a blue spectrum light is shined on the material to force the plastic to cure. If a blue spectrum light is not used it is probably because a different brand of sealant is being used. Some brands of sealants cure chemically.
After the sealants have hardened it turns into a thin layer of plastic covering the back teeth. Generally sealants can last up to five years or longer, although they should be checked periodically for damage. If sealants become damaged they can easily be replaced simply by adding new sealant material to the worn areas.