Comparative evaluation of debris extruded apically during endodontic retreatment using hedstrom files and two rotary nickel titanium (niti) instruments, k3 and protaper universal retreatment files

Aim: To evaluate and compare the amount of debris extruded apically during Endodontic retreatment using manual Hedstrom and rotary k3, ProTaper Universal Retreament instruments. Materials and method: 45 Extracted human single straight rooted mandibular first premolar teeth were used in this study. After the conventional access cavity preparation and working length determination, cleaning and shaping was done with a modified step back flare technique using Gates Glidden drills and K-files to a master apical file size of #30 and stepped back in 1-mm increments with four subsequent instrument sizes #35, #40, #45, #50 K-file. Obturation was done with 0.02 taper Gutta percha points and AH PLUS root canal sealer in a cold lateral condensation technique. Plastic Eppendorf tube of capacity 2ml was used as the collecting container for any debris or irrigant extruded apically from the tooth during retreatment. Grouping was done as follows Group I- Control group – No gutta-percha removal, Group II-Gutta-percha removal with Hedstrom files, Group III-Gutta-percha removal with K3 files, Group IV-Gutta-percha removal with Protaper Universal Retreatment files. The Eppendorf tubes were stored in an Incubator at 37 ºC for 21 days to evaporate the irrigant before weighing the dry debris. The tubes with the dried debris were weighed using the Analytical balance. Weight of extruded debris= Weight of Eppendorf tube with dried debris MINUS Pre-weighted weight of empty Eppendorf tube. Results: Observations were then statistically analyzed using Analysis of variance (One way ANOVA) and the difference among four groups were evaluated by students ‘t’ test for pair wise comparision. There was a statistical significant difference among all the groups in the amount of debris extruded except group III and IV. Conclusion: All retreatment techniques resulted in debris extrusion during Endodontic retreatment. Retreatment with manual Hedstrom files resulted in significantly greater extrusion of debris when compared to rotary K3 and ProTaper Universal Retreatment instruments.