A filling and crown have similar functions, but there are several differences between the two, as a dentist Beverly Hills residents trust can tell you. They both are put on damaged teeth, and are used to treat cavities. A filling is applied to cavities that don’t take up the entire tooth, and are made of a composite material or soft metal. Fillings are usually applied to cavities that are not that deep. A crown is like a cap that is put on the top of a tooth that has damaged enamel, so the top of the tooth is worn out. It protects the tooth by preventing further decay and, as well as restores the shape.