The purpose of this study was to determine whether electrical current
can travel between adjacent teeth through contacting interproximal ama
lgam restorations. Twenty-two extracted human premolars were restored
with class II amalgam restorations. They were then mounted in pairs in
self-curing resin, simulating adjacent teeth. Only their restorations
were allowed to contact. An electrical multimeter was used to supply
electrical current and to measure any current passing through the moun
ted teeth. One current measurement was made from the buccal enamel of
a tooth to the occlusal surface of the filling in that tooth. A second
measurement was made from the buccal enamel of the same tooth to the
occlusal surface of the adjacent filling. These two measurements were
made for all 11 trials. Statistically, all current that entered the fi
rst tooth passed to the adjacent tooth. This finding suggests a potent
ial source of error when using an electric pulp tester.