Suk M, et al. - The efficacy of photon-initiated photoacoustic streaming (PIPS) in the removal of filling remnants from root canals after the rotary phase of retreatment was evaluated. Furthermore, the physicians investigated the difference in the amount of residual material considering the type of sealer. During the rotary phase of the retreatment, the MTA Fillapex (Angelus Solucoes Odontologicas, Londrina, Brasil) was the most easily removed. After the rotary phase of the retreatment, there were no differences in the amount of the remaining filling material between EndoSequence BC and the AH Plus groups. In all groups, the PIPS improved the removal of filling remnants.