Related Experiment Video
Updated: Jul 7, 2026
Scanning Electron Microscopic Evaluation of Surface Defects of Remover Retreatment File After Single and Multiple Uses
Published on: October 11, 2024
Retreatability of root canals filled with gutta percha and a novel bioceramic sealer- a scanning electron microscopy
Dsv Sindhuja1, Prashant Bhasin1, Hemanshi Kumar1
1Department of Conservative Dentistry and Endodontics, Sudha Rustagi College of Dental Sciences and Research, Affiliated to Pandit B.D. Sharma University of Health Sciences and Research, Haryana, India.
Objective:
To compare effectiveness of 5% acetic acid, 10% formic acid, and chloroform used adjunctively with a rotary retreatment system in removing a premixed calcium-silicate sealer (Ceraseal) and gutta-percha from root canals, using scanning electron microscopy (SEM) to quantify residuals across canal thirds.
Materials And Methods:
Thirty-six extracted single-rooted anterior teeth were instrumented, obturated (single-cone GP + Ceraseal), and stored for two weeks. Specimens were retreated with HyFlex Remover files and randomly assigned (n = 9/group) to: G1-5% acetic acid; G2- 10% formic acid; G3-chloroform; G4-distilled water (negative control). Two milliliters of test solution were used with repeated instrumentation until patency; canals were then irrigated with saline and dried. Roots were split; standardized SEM images (×1000) of coronal, middle, and apical thirds were scored.
Results:
Intragroup, residuals increased apically in all solvent groups: in G1, apical > middle > coronal (all p = 0.021); in G2, apical > coronal/middle (p = 0.021); in G3, apical > coronal (p = 0.021); G4 showed no significant intragroup differences. Intergroup, coronal third: G1 had significantly lower residuals than G3 and G4; G1 ≈ G2; G2 ≈ G3 ≈ G4. Middle third: G1 and G2 < G4 (p = 0.021); no other pairwise differences. Apical third: no significant between-group differences.
Conclusions:
When combined with HyFlex Remover files, 5% acetic and 10% formic acids enhanced removal of Ceraseal/gutta-percha, particularly in coronal third; 5% acetic outperformed chloroform coronally. In middle and apical thirds, acidic solvents, chloroform, and water yielded broadly comparable outcomes.
