A special dental paint is used to paint the chewing (occlusal) surface of your tooth.
A dental sealant (or fissure sealant) is a preventative treatment that seals the patterns on the tops of your back teeth to help protect them. This flows into all the nooks and crannies to seal them, making the tooth easier to keep clean and less likely to decay.
Fissure sealants are generally placed on the molar teeth- most commonly your first permanent molar, but they can also be placed on the second permanent molar if necessary.
If you have decay in one of your first permanent molars, all of them (the remaining three) should be sealed and if you have decay in more than one, it might be a good idea to seal all the second permanent molars too.