Temperature changes during the finishing of amalgam restorations

The finishing and polishing of amalgam restorations may be harmful to the pulp because of the heat generated during these procedures. In this study, changes in temperature of the pulp in extracted teeth were determined in vitro. During the polishing procedure, a variety of instruments were used under a variety of circumstances: with or without a water coolant, intermittent or continuous operation, high or low rotation speed, and high or low pressure. Finishing or polishing without a water coolant always increased the temperature of the pulp. When the pressure was high, during continuous polishing, or during a higher velocity of rotation, pulpal temperatures increased more than 20 degrees C within 30 seconds. However, when a water coolant was used, a decrease in the temperature was always observed. Procedures carried out with low pressure showed a decrease in the pulpal temperature of approximately 9 degrees C. High pressure decreased the temperature of the pulp by only 4 degrees C. Therefore a water coolant is always advised when amalgam restorations are being finished and polished.