If the nerve is infected, baby teeth respond well to the removal of a diseased part of the dental pulp while leaving the healthy portion intact.  The cavity is removed from the tooth in addition to the portion of the pulp that has been infected by the bacterial growth from the cavity.  A disinfectant is placed on top of the remaining pulp, the tooth is sealed and a crown (silver cap) is placed over the tooth.  This allows the tooth to stay vital (alive) within the mouth.