Removal of overextended root canal filling beyond the apex in lower premolar teeth using two different retreatment rotary files versus manual files: a comparative in vitro study

BACKGROUND: The aim of the study was to compare the time required for complete removal of overextended root canal filling in lower premolar teeth using two different rotary file systems; ProTaper Universal Retreatment (PTUR) system, XP-endo Retreatment (XPER) system versus manual Hedstrom (H-Files). METHODS: Thirty-six extracted permanent mandibular premolars with single canal were set to a standard length of 19 mm and prepared beyond the apical foramen by 3 mm up to F2 file of the ProTaper Gold system. Overextended obturation was performed by a size (25/08) gutta-percha and AH-Plus sealer using cold lateral condensation technique. Teeth were left for 7 days to ensure complete setting of sealer, then divided into 3 groups (n = 12) according to the gutta-percha removal method (Group Ι: H-Files, Group ΙΙ: PTUR, Group ΙΙΙ: XPER (XP-endo Shaper (XPES) + XP-endo Finisher R (XPEF-R)). Time taken was recorded and statistically analyzed. RESULTS: The XPER technique showed a statistically significant reduction in the time taken to remove the overextended gutta-percha compared to H-files and PTUR groups (P < .05), with the XPER group showing the shortest time, followed by PTUR, and then H-files. CONCLUSIONS: XPER technique was significantly faster in removing the experimentally overextended gutta-percha than H-files and PTUR files, demonstrating superior procedural time efficiency.