Electrochemical Reactions During Constant DC Current Stimulation: An In Vitro Experiment with Cultured Rat Calvarial Cells

Abstract

While various electrode materials, methods of insertion, and levels of current and voltage have been used in animal experiments and clinical situations, the mechanism for constant direct current (DC) stimulation is still unknown. Little information has been provided on the behavior of active metallic electrodes in the complex biochemical environment. The findings of this study are the following: (1) Electrochemical reactions in culture medium (DMEM + 10% FBS) were recorded at a current density of 85 μA/cm². Current density higher than 212 μA/cm² leads to acute reactions including liberation of H₂. (2) O₂ plays an important role in the electrochemical reaction. (3) The resistance of the culture medium increased exponentially during electrical stimulation. (4) pH increased in the region around the cathode as a function of current density and time. (5) The initial response of osteoblastic cells to a DC current of 100 μA/ cm² is proliferation and alignment parallel to field lines. Studies on mechanisms and techniques of DC stimulation may lead to revolutionary changes in general clinical practice.