HESI General Chairside Assisting Practice Exam 2025 – Complete Study Resource

Galvanic action refers to the occurrence of an electric current that is generated when two different metals come into contact in the presence of an electrolyte. In dentistry, this phenomenon is most notably recognized in the context of dental amalgam. Amalgam consists primarily of metals such as silver, mercury, tin, and copper. When amalgam is used in a restoration and comes into contact with other metallic dental materials, such as gold crowns or fillings, and is exposed to moisture (which can act as the electrolyte), galvanic currents can be formed.

This can lead to unpleasant sensations, referred to as "galvanic shock," experienced by the patient. While composite resins, glass ionomers, and dental cements do have their respective properties and applications, they do not typically engage in galvanic action because they do not contain metallic components in a manner that allows for the same electrochemical reactions. Thus, amalgam's unique composition and interactions with other metals make it the restorative material associated with galvanic action.