The back teeth (ie. molars and premolars) are often formed with deep grooves and pits on their biting surfaces. Unfortunately, plaque often gets trapped at the base of these pits and grooves where it is difficult or impossible to remove. This plaque can then cause tooth decay and cavities to develop on these areas of the teeth. To prevent this plaque from getting lodged in these pits and grooves, dental sealants can be placed to protect the teeth. The teeth are first cleaned and dried very thoroughly. Then, a sealant material, which is a white or clear liquid plastic, is brushed into the pits and grooves to plug them up. Finally, a special light is shone onto the teeth to change the sealant from a liquid into a hard solid plastic. Now, the pits and grooves are sealed to prevent decay from starting in them.