An evaluation and comparison of the pulpal response to gold foil and indium alloy.

All teeth restored with gold foil had pulpal changes marked by persistent hemorrhage, destruction of odontoblasts, and inflammation. Bacteria were found more frequently on cavity walls of teeth restored with gold foil and with increasing frequency for all materials as the observation period became longer. The presence or absence of bacteria could not be related to the pulpal response for either indium alloy or gold foil. Because this and previous studies indicated that gold foil in direct contact with prepared dentin surfaces produces pulpal injury, a base to protect the pulp is indicated. Indium alloy or another appropriate base could be used for the required pulpal protection.