Stress-induced bioelectric potentials in the dentoalveolar complex

Abstract Deforming forces were applied to teeth and their supporting structures, both as integral mechanical units and as component parts (that is, enamel, dentine, cementum, and alveolar bone). Both the amplitude and polarity of the resultant charge separation (voltage or potential difference) were recorded from a variety of sites about many teeth, and a “charge-polarity map” was obtained. A comparison between the “maps” and the cellular responses known to occur during orthodontic procedures produced correlations which were consistent with previous studies on long bones. Areas that have been described as characterized by osteoblastic activity were routinely electronegative and, conversely, areas of positivity or electrical neutrality were observed in regions characterized by osteoclasia during orthodontic tooth movement. A re-evaluation of the current “pressure-tension” hypothesis regarding the behavior of bone during orthodontic tooth movement may well be indicated. The current “pressure-tension” hypothesis is sufficient to explain only the intermediate steps in the transfer of applied forces to the surrounding alveolar bone but does not, in itself, clearly define the resultant mechanical or electrical behavior of the alveolar bone.