Effect of restoration thickness on the sealing ability of TERM

An in vitro study was done using a fluid filtration device to compare microleakage of Temporary Endodontic Restorative Material (TERM) at various thicknesses. Forty-four extracted mandibular molars had their roots removed at the cementoenamel junction, occlusal table flattened, and a standardized endodontic access made in the crown. The teeth were restored with TERM in thicknesses of 1, 2, 3, and 4 mm, and quantitatively measured for leakage (microliters/min) at intervals of 1 and 24 h and 1, 3, and 5 wk. Thermocycling was accomplished at the 5-wk interval. Positive controls received 4-mm-thick IRM or gutta-percha restorations and were measured at 24 h only. Repeated measures of analysis of variance found no significant difference (p < 0.05) in leakage values in any group over time or between any of the different thicknesses. Positive controls showed significantly more leakage than all other groups. TERM maintained as tight a seal at 1-, 2-, and 3-mm thicknesses as it did at 4 mm and may be suited for clinical situations where less than 4 mm of restorative space exists.