The present invention provides a method of treating a condition affecting a tooth or periodontium in a subject, comprising administering to the subject's tooth or periodontium a composition comprising biocompatible magnetic, magnetizable, or magnetically responsive agents； and applying an external magnetic field, wherein the magnetic, magnetizable, or magnetically responsive agents migrate to a desired location in response to the externally applied magnetic field, thereby treating a condition affecting the tooth or periodontium in the subject.
