A sealant is a white coating applied to the chewing surfaces of the back teeth. The resin flows into the pits and grooves of the back teeth. Once they are covered, food and plaque cannot get in. The sealant forms a barrier against acid attacks. Tooth decay often occurs on the chewing surfaces of the back teeth. The good news is that sealants can help protect these surfaces from tooth decay and improve your child’s chances to stay filling-free.