A comprehensive survey of 226 patients with an allergy to metal alloys applied in the clinic prosthodontics. In this study, the total Immunoglobulin E (IgE), specific IgE-and Immunoglobulin G (IgG)-antibodies to metal ions in serum and in mixed saliva were measured. In the mixed saliva no significant increasing in IgE-antibodies to metal ions has been revealed, IgGantibodies to gold, cobalt, chromium, nickel, copper, palladium and platinum ions in low titers were defined in elderly patients. To predict the development of allergic reactions in patients with metal alloys prosthetic constructions, specific serum IgG-antibodies to metal ions that characterize the frequency of contact with the allergen were measured. The content of specific IgE-antibodies to metal ions in serum measured to recognize a primary response to allergens (no history of contact with the metal alloys used in prosthetic dentistry). The investigation of specific IgE-and IgG-antibodies to metal ions in serum has shown the largest number of positive tests to copper (11.3%), gold (10.8%), cobalt (9.9%) and nickel ions (9.3%). The verification of clinical and diagnostic significance of revealing specific antibodies to metal ions in patients with allergies to metal alloys used in prosthetic dentistry, showed that the use of these methods is an auxiliary diagnostic tool and it can only be interpreted in conjunction with the results of clinical examination of the patients.