Effects of calcium hydroxide paste as an intracanal medicament on apical seal

Seventy-six extracted human permanent canines and premolars with single canals were used in this study. The crowns were removed, the canals were instrumented, and the roots were randomly divided into four groups of 18 each. Three groups were medicated with Ca(OH)2 USP, Calasept, and Vitapex, respectively, while the control group was not medicated. The roots were incubated in 100% relative humidity at 37 degrees C for 1 wk, after which the medicaments were removed and the canals were enlarged to the next file size. One tooth in each group was examined in the scanning electron microscope while the remaining roots were filled with gutta-percha using a lateral condensation technique. The roots were placed in 2% methylene blue solution for 2 wk and both linear and volumetric dye penetration evaluated. A highly significant correlation between linear and volumetric leakage was observed. The leakage among the experimental groups was not significantly different, but was significantly less than in the control group.