Is there a battery in your mouth? Oral galvanic currents effect, or battery effect as it is also called, is produced when incompatible metals exist in your mouth are continually exposed to saliva. The measurable amounts of energy coming from these metals, in the form of fillings, implants and crowns, can have a significant impact on the nervous system and brain function. Our testing protocol can identify the presence of galvanic current and offer biocompatible options.