Sealants are a painless preventative to help prevent tooth decay. They are recommended for all children and cavity prone adults. The tooth is etched, or roughened, so the sealant material will bond to the surface. The material is a liquid, milky in color and will flow in to the grooves of the teeth. A violet colored light is used to harden the material. This provides a seal, much like polyurethane seals wood from water. The sealants through time may loosen or crack. They can easily be replaced.