Don’t Rely on the Dental Metal Activity Meter

Stephen Barrett, M.D.
March 19, 2005
The Dental Metal Sensitivity Meter (“DMA-Meter”) is claimed to be able to help dentists determine whether the metallic alloys used to make fillings, crowns, and bridges are causing or are likely to cause health problems for the patient. To use the device, the dentist touches one electrode to the restorative material and the other to the soft tissue inside the patient’s mouth. The resultant reading is said to enable the dentist to judge how the metal of an intended restoration “influences the electrochemical condition of the patient.” Proponents further claim:

  • When metals such as cadmium, indium, nickel, vanadium, and zinc come in contact with saliva they form a “battery” that causes metallic ions (electrically charged particles) to be discharged into the mouth, from which they can enter the bloodstream.
  • In addition to gum disease, this process can lead to allergies, dizziness, eczema, hair loss, headaches, high blood pressure, joint pains, precancerous lesions, generalized skin rashes, and “especially disorders of the immune system.” [1,2]
  • The DMA-Meter measures the extent to which metallic ions are discharged from the metal alloy.

I don’t believe that any of the above claims are true.

The manufacturer’s Web site contains pictures of eight patients with various rashes said to be cause by allergy to amalgam, chromium, nickel, and/or palladium. My dental consultants have advised me that (a) some of the diagnoses look incorrect; (b) few if any of the conditions represent allergic responses to dental metals, and c) It is improper to conclude that a dental metal causes an allergy without patch-testing, elimination of the alleged cause, and possibly a challenge test in which the patient is re-exposed to the material. We do not believe that measuring some electrical voltage in the mouth is relevant to the diagnosis of allergy.

References
  1. Which advantages offers the use of the DMA-Meter. DMA Meter Web site, accessed March 17, 2005.
  2. Dental metal activity meter. Southwest Florida Dental of Ft. Meyers Web site, accessed March 17, 2005.

This article was posted on March 19, 2005.