Research Article

Evaluation of operator experience and nickel–titanium retreatment file systems in curved root canals

Volume: 60 Number: 1 September 7, 2026
EN

Evaluation of operator experience and nickel–titanium retreatment file systems in curved root canals

Abstract

Purpose

The aim of this study was to evaluate the influence of operator experience and four different nickel–titanium (NiTi) retreatment systems in curved canals with respect to procedural time, complications, and file distortions during root canal filling removal.

Materials and methods

Root canal treatment was performed on 80 acrylic blocks with a 30° curvature. The blocks were assigned to either an endodontist or an endodontic resident (n = 40 each) and further divided into four subgroups (n = 10) according to the retreatment system used: ProTaper Universal Retreatment, ROGIN Retreatment Files, FANTA AF Retreatment Files, and EndoArt Retreatment Gold. Procedural time, complications (perforation, ledge formation, and apical transportation), and file distortions (unwinding, tip deformation, and instrument separation) were recorded.

Results

The median procedural time for the endodontist (120 [95–142]) was significantly shorter than that for the resident (145 [117–162]) (p = 0.007). No statistically significant differences were observed between operators with regard to complications. The ProTaper Universal Retreatment system exhibited the lowest overall complication rates numerically. Additionally, both the FANTA AF Retreatment Files and the ProTaper Universal Retreatment system demonstrated a lower incidence of ledge formation when used by the resident; however, this difference did not reach statistical significance.

Conclusion

The endodontist completed the procedures faster than the endodontic resident. The ProTaper Universal Retreatment system showed the lowest overall number of complications across both operators. The FANTA AF Retreatment Files demonstrated the lowest incidence of ledge formation, whereas EndoArt Retreatment Gold exhibited the highest incidence.

Keywords

References

  1. Ruddle CJ. Nonsurgical retreatment. J Endod. 2004;30:827–45. [CrossRef ] google scholar
  2. Viducić D, Jukić S, Karlović Z, Bozić Z, Miletić I, Anić I. Removal of gutta-percha from root canals using an Nd:YAG laser. Int Endod J. 2003;36:670–3. [CrossRef ] google scholar
  3. Schirrmeister JF, Wrbas KT, Meyer KM, Altenburger MJ, Hellwig E. Efficacy of different rotary instruments for gutta-percha removal in root canal retreatment. J Endod. 2006;32:469–72. [CrossRef ] google scholar
  4. Kosti E, Lambrianidis T, Economides N, Neofitou C. Ex vivo study of the efficacy of H-files and rotary Ni-Ti instruments to remove gutta-percha and four types of sealer. Int Endod J. 2006;39:48–54. [CrossRef ] google scholar
  5. Saad AY, Al-Hadlaq SM, Al-Katheeri NH. Efficacy of two rotary NiTi instruments in the removal of Gutta-Percha during root canal retreatment. J Endod. 2007;33:38–41. [CrossRef ] google scholar
  6. Schäfer E, Dzepina A, Danesh G. Bending properties of rotary nickel-titanium instruments. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2003;96:757–63. [CrossRef ] google scholar
  7. Ayar LR, Love RM. Shaping ability of ProFile and K3 rotary Ni-Ti instruments when used in a variable tip sequence in simulated curved root canals. Int Endod J. 2004;37:593–601. [CrossRef ] google scholar
  8. Taşdemir T, Er K, Yıldırım T, et al. Efficacy of three rotary Ni-Ti instruments for gutta-percha removal in root canal retreatment. Int Endod J. 2008;41:217–23. [CrossRef ] google scholar

Details

Primary Language

English

Subjects

Endodontics

Journal Section

Research Article

Publication Date

September 7, 2026

Submission Date

July 7, 2025

Acceptance Date

October 20, 2025

Published in Issue

Year 2026 Volume: 60 Number: 1

APA
Özden, İ., Çil, A., Cilli, B., Gökyar, M., Ayhan, T., & Sazak Öveçoğlu, H. (2026). Evaluation of operator experience and nickel–titanium retreatment file systems in curved root canals. European Oral Research, 60(1), 222-229. https://doi.org/10.26650/eor.20261736346
AMA
1.Özden İ, Çil A, Cilli B, Gökyar M, Ayhan T, Sazak Öveçoğlu H. Evaluation of operator experience and nickel–titanium retreatment file systems in curved root canals. EOR. 2026;60(1):222-229. doi:10.26650/eor.20261736346
Chicago
Özden, İdil, Arzu Çil, Beste Cilli, Merve Gökyar, Tuba Ayhan, and Hesna Sazak Öveçoğlu. 2026. “Evaluation of Operator Experience and Nickel–titanium Retreatment File Systems in Curved Root Canals”. European Oral Research 60 (1): 222-29. https://doi.org/10.26650/eor.20261736346.
EndNote
Özden İ, Çil A, Cilli B, Gökyar M, Ayhan T, Sazak Öveçoğlu H (September 1, 2026) Evaluation of operator experience and nickel–titanium retreatment file systems in curved root canals. European Oral Research 60 1 222–229.
IEEE
[1]İ. Özden, A. Çil, B. Cilli, M. Gökyar, T. Ayhan, and H. Sazak Öveçoğlu, “Evaluation of operator experience and nickel–titanium retreatment file systems in curved root canals”, EOR, vol. 60, no. 1, pp. 222–229, Sept. 2026, doi: 10.26650/eor.20261736346.
ISNAD
Özden, İdil - Çil, Arzu - Cilli, Beste - Gökyar, Merve - Ayhan, Tuba - Sazak Öveçoğlu, Hesna. “Evaluation of Operator Experience and Nickel–titanium Retreatment File Systems in Curved Root Canals”. European Oral Research 60/1 (September 1, 2026): 222-229. https://doi.org/10.26650/eor.20261736346.
JAMA
1.Özden İ, Çil A, Cilli B, Gökyar M, Ayhan T, Sazak Öveçoğlu H. Evaluation of operator experience and nickel–titanium retreatment file systems in curved root canals. EOR. 2026;60:222–229.
MLA
Özden, İdil, et al. “Evaluation of Operator Experience and Nickel–titanium Retreatment File Systems in Curved Root Canals”. European Oral Research, vol. 60, no. 1, Sept. 2026, pp. 222-9, doi:10.26650/eor.20261736346.
Vancouver
1.İdil Özden, Arzu Çil, Beste Cilli, Merve Gökyar, Tuba Ayhan, Hesna Sazak Öveçoğlu. Evaluation of operator experience and nickel–titanium retreatment file systems in curved root canals. EOR. 2026 Sep. 1;60(1):222-9. doi:10.26650/eor.20261736346