On electric current creation in patients treated with osseointegrated dental bridges

Electric currents are created when metals or metal alloys are immersed and make contact with each other in an electrolyte. As such metallic contacts are created in the oral cavity also at treatments with osseointegrated fixed bridges ad modum Brånemark, the generated currents were studied in vivo. In four subjects, all wearing osseointegrated mandibular dental bridges and complete maxillary acrylic dentures, the bridges were removed leaving the osseointegrated titanium abutments exposed in the oral cavity. Potentials and polarizations were determined independently for all the titanium abutments and gold alloy bridges and from the obtained data the maximum electric currents generated at contact between the materials were calculated. The results of this study showed that, generally speaking, in the oral cavity dental gold alloy was electrochemically more noble than titanium implants. The mean potential difference between the two metallic systems was found to be 73 mV and the mean generated maximum electric currents was in the magnitude of 26 microA at oral contacts between titanium and dental gold alloy.