I was told that I should get sealants on my child's teeth. What are they and are they really necessary?

Sealants are clear/white coating that is put on the pits and fissures of biting surfaces of posterior teeth. It is pretty much like nail polish we put on teeth, there is no numbing or anything. It is painted on then dried with a light or either air drys depending on what kind of sealant is placed. We try to do this right as the permanent teeth come in so there is no chance of decay while they are still erupting. I would recommend getting a glass ionomer sealant because it has a fluoride releasing agent and is actually a chemical bond between the tooth instead of a tradition sealant that is like a plastic coating over the tooth. But both do the job of prevent decay. They can get expensive in private practice but it should be fine with insurance. If you are worried about the cost you can always check the local dental hygiene clinic and they are really cheap.