Dental sealants are protective covering of the teeth to keep it from bacterial attacks which in turn cause cavities. Mostly, it is applied to children with permanent teeth which have just erupted. The main purpose for this kind of dental procedure or treatment is to cover the teeth to keep food debris and cavity causing bacteria from getting deposited in the pits, grooves and fissures and help prevent decay. Even though the best time to place these sealants are for a molar that just erupted, which is usually around age six, anyone at any age can have this procedure done. The only criteria is that the teeth have to be decay free. So if your tooth already has a cavity, then it is too late to do sealants.