Efficacy of various rotary retreatment instruments for gutta percha removal: An in vitro study

Abstract

Background: Failure of endodontic treatment may necessitate retreatment by removing gutta percha from root canals. The present study evaluated the efficiency of retreating gutta-percha obturated root canalas with protaper universal retreatment files, endo retreatment files, nrt gpr retreatment files and h files, while using the sealers, ah plus and zinc oxide euginol for obturation. Materials and Methods: Intact single rooted 120 mandibular premolars were decoronated to obtain a standardized root length of 15 mm. Canals were obturated using thermoplasticized gutta percha (GP) with either AH Plus or Endofill as sealer. The roots were randomly divided into 8 groups, with 15 teeth in each group, and gutta percha removal was done using H files, (PTUR Protaper universal retreatment), R Endo and NRT GPR (Nickel titanium gutta percha remover), for studying their efficiency in terms of total operating time and GP remnants left in the canal by using Confocal Raman Microscope. Results: The order of efficiency in terms of time and gutta percha (GP) removal was PTUR > R-Endo > NRT GPR > H-files. The difference in GP removal was not statistically significant but the time taken for removal was statistically significant. The use of AH Plus sealer showed more remnants than Endofill sealer and the file system followed the same order of efficiency, but the difference was not statistically significant. Conclusion: The rotary retreatment system proved to be more efficient than hand files for gutta percha removal.