Bago I, et al. - Experts compared the Reciproc Blue, Reciproc, and ProTaper Universal Retreatment systems with regard to the effective removal of epoxy resin-based sealer and gutta-percha during the retreatment of oval, straight root canals. Findings suggested a greater effectiveness of the Reciproc system vs the Reciproc Blue and ProTaper Universal Retreatment systems during the removal of filling material from oval, straight canals, however, the filling material was not completely removed by any of the systems.