Does the presence of full-coverage crown interfere with removal of obturation material: A cone-beam computed tomography image segmentation volumetric analysis.

Aim: The aim of this study was to assess and compare the influence of the presence of full-coverage crown on the obturation material removal efficiency of different retreatment file systems.

Materials and methods: Sixty extracted, human, maxillary premolars were accessed, instrumented, and obturated with gutta-percha and AH Plus sealer. The samples were scanned with cone-beam computed tomography and volume of obturating material was measured using ITK-SNAP volumetric software. Samples were divided (n = 30) into with and without all metal full-coverage crown groups. Each group was then subdivided into three subgroups (n = 10) based on retreatment file used (ProTaper URS, HyFlex Remover, and NeoEndo). The volume of remnants of obturating material was remeasured by image segmentation using ITK-SNAP volumetric software. One-way analysis of variance, followed by the Tukey's post hoc test, was used for data analysis, with a significance level of 5%.

Results: A significant difference in percentage remnant of obturating material after retreatment file was observed on overall comparison between with (29.84%) and without crown (21.79%) groups (P < 0.05). Each file system removed significantly more obturating material in without crown samples than with crown samples (P < 0.05). The percentage remnant of obturating material after retreatment file use was as follows: ProTaper URS > NeoEndo retreatment file > HyFlex Remover. All file systems showed significantly different (P < 0.05) efficiency in removal of obturating material.

Conclusions: None of the retreatment file systems were able to remove obturating material completely. The presence of full-coverage crown negatively impacted the efficiency of retreatment files for the removal of obturating material. HyFlex Remover performed better than NeoEndo which was better than ProTaper URS.