Evaluation of temporary restorations' microleakage by means of electrochemical impedance measurements

The aim of this study was to quantify the changes in the watertightness of three temporary filling materials over 1 wk with a new electrochemical technique: the impedance measurement technique. Forty sound extracted human maxillary teeth were selected and prepared for the measurements. They were divided into three groups in addition to positive and negative controls. The resistance, and therefore the watertightness, of the intact crown and the resistance after preparation of an endodontic access cavity were registered. After a randomization procedure, 12 teeth were obturated with Cavit G, 12 teeth with Fermit-N, and 12 teeth with Intermediate Restorative Material (IRM). The changes in the resistance were measured first just after obturation (time 0), then after days 1, 2, 3, 4, and 7. The results showed that the IRM group was significantly more watertight than the Fermit-N group (p < 0.05) and much more than the Cavit G group (p < 0.005).