The crown for differential diagnostics galvanos, executed of fast-hardening plastic of type «Akrodent», contains a crown, a layer of fi xing cement and a metal ledge, thus it follow-up contains a metal ledge, thus it followup contains a metal exemplar with a ledge of a rectangular form and fi xing elements. She allows to receive steady indications biopotentialometr which objectively refl ect values of electrochemical potentials of the metal designs made of the given alloy which will be established on them in an oral cavity of the patient in 1 hour after orthopedic treatment. The way allows quickly and to pick up precisely an alloy of metal for a planned orthopedic design.