A retrospective study was done to compare the success rates of teeth with three different root end filling materials. The materials studied were SuperEBA, IRM, and zinc-free high-copper spherical amalgam. Radiographs of 488 cases from two geographically distinct offices were used, with the recall period ranging from a minimum of 6 months to a maximum of 10 yr. The cases in each office were examined independently using the same criteria. The results revealed that both SuperEBA and IRM demonstrated statistically significant improvements in success rates when compared with amalgam. The success rates were 75% for amalgam, 91% for IRM, and 95% for SuperEBA. The difference between IRM and SuperEBA was not statistically significant.