The Effect of Sterilization Procedures and Different Irrigation Solutions on Surface Roughness of Nickel-Titanium Files: An Atomic Force Microscopy Study

Enes Elmali; Faruk Oztekin

doi:10.61139/ijdor.1816822

The Effect of Sterilization Procedures and Different Irrigation Solutions on Surface Roughness of Nickel-Titanium Files: An Atomic Force Microscopy Study

Abstract

Background: The present study aimed to assess how different irrigation solutions and sterilization procedures influence the surface morphology of ProTaper Next (PTX) and Reciproc Blue (RB) Nickel-Titanium (NiTi) endodontic instruments.
Materials and Methods: Sixty rotary NiTi files were evaluated-thirty PTX and thirty RB. Each instrument system was randomly divided into five subgroups (n=6). Three groups were dynamically immersed for 5 minutes in 5.25% sodium hypochlorite (NaOCl), BioAKT, or 18% etidronic acid (HEBP). Another group was exposed to five consecutive autoclave sterilization cycles, while one subgroup served as the untreated control. Surface characterization was performed using atomic force microscopy (AFM) operated in tapping (non-contact) mode. Five random sites within the apical 3 mm of each sample were scanned over a 5 μm × 5 μm area. Three-dimensional surface profiles were processed with XEI software to determine the root mean square (RMS) roughness and depth parameters. Statistical analyses were carried out using the Kolmogorov-Smirnov test, one-way ANOVA, and post hoc LSD test, with the level of significance set at p<0.05.
Results: AFM analysis revealed nanoscale surface irregularities across all groups, including untreated controls. The RMS and depth values were significantly higher in files exposed to NaOCl, BioAKT, and HEBP compared with the control group (p<0.05). Similarly, instruments subjected to multiple autoclave cycles exhibited a marked increase in both RMS and depth values (p<0.05). The obtained data indicated consistent trends between the two instrument systems.

Conclusions: Exposure to NaOCl, etidronic acid, BioAKT, and autoclave sterilization significantly increased the surface roughness of PTX and RB NiTi files. Among all tested conditions, HEBP and repeated sterilization produced the most pronounced alterations in surface parameters.

Keywords

Supporting Institution

Firat University

Ethical Statement

Since root canal files were studied, ethics committee approval was not obtained.

References

Mamat R, Nik Rozainah N A G. The complexity of the root canal anatomy and its influence on root canal debridement in the apical region:a review. Cureus. 2023;15(11):e49024.
Peters OA. Current challenges and concepts in the preparation of root canal systems:a review. Journal of Endodontics. 2004;30(8):559-67.
Zehnder M. Root canal irrigants. Journal of Endodontics. 2006;32(5):389-98.
Zehnder M, Schmidlin P, Sener B, Waltimo T. Chelation in root canal therapy reconsidered. Journal of Endodontics. 2005;31(11):817-20.
Tartari T, Guimarães BM, Amoras LS, Duarte MAH, Bramante CM. Etidronate causes minimal changes in the ability of sodium hypochlorite to dissolve organic matter. International Endodontic Journal. 2015;48(4):399-404.
Tonini R, Generali L, Pedullà E, Prati C, Gandolfi MG. In vitro evaluation of antibacterial properties and smear layer removal/sealer penetration of a novel silver-citrate root canal irrigant. Materials. 2020;13(1):1-13.
Generali L, Puddu P, Borghi A, Brancolini S, Lusvarghi L, Bolelli G, et al. Mechanical properties and metallurgical features of new and ex vivo used Reciproc Blue and Reciproc instruments. International Endodontic Journal. 2020;53(2):250-64.
Jung WK, Koo HC, Kim KW, Shin S, Kim SH, Park YH. Antibacterial activity and mechanism of action of the silver ion in Staphylococcus aureus and Escherichia coli. Applied and Environmental Microbiology. 2008;74(7):2171-8.

Yared G. Canal preparation using only one Ni-Ti rotary instrument:preliminary observations. International Endodontic Journal. 2008;41(4):339-44.
Kandaswamy D, Venkateshbabu N, Porkodi I, Pradeep G. Canal-centering ability:An endodontic challenge. Journal of Conservative Dentistry. 2009;12(1):3-9.
Alapati SB, Brantley WA, Iijima M, Clark WAT, Kovarik L, Buie C. Proposed role of embedded dentin chips for the clinical failure of nickel-titanium rotary instruments. Journal of Endodontics. 2004;30(5):339-41.
Chakka NV, Ratnakar P, Das S, Bolla N, Narayana V. Do NiTi instruments show defects before separation?Defects caused by torsional fatigue in hand and rotary NiTi instruments leading to failure during clinical use. Journal of Contemporary Dental Practice. 2012;13(6):867-72.
Nóvoa XR, Chao C, Izquierdo C, Rivas F, Pérez M. The corrosion of nickel-titanium rotary endodontic instruments in sodium hypochlorite. International Endodontic Journal. 2007;40(1):36-44.
Spagnuolo G, Ametrano G, D'Antò V, Rengo C, Simeone M, Riccitiello F, et al. Effect of autoclaving on the surfaces of TiN-coated and conventional nickel-titanium rotary instruments. International Endodontic Journal. 2012;45(12):1148-55.
Allison DP, Hinterdorfer P, Han W. Atomic force microscopy of biological samples. Wiley Interdisciplinary Reviews:Nanomedicine and Nanobiotechnology. 2010;2(6):618-34.
Valois CR, Silva LP, Azevedo RB. Multiple autoclave cycles affect the surface of rotary nickel-titanium files:an atomic force microscopy study. Journal of Endodontics. 2008;34(7):859-62.
Pashley DH. Smear layer:physiological considerations and clinical applications. Operative Dentistry. 2002;27(5):475-482.
Elamam RF, Capelas JA, Vieira MF. Effect of repeated use on topographical features of ProTaper Next endodontic rotary files. International Journal of Oral Health. 2016;8(4):445-50.
Cazaux J. Recent developments and new strategies in scanning electron microscopy. Journal of Microscopy. 2005;217(Pt 1):16-35.
Inan U, Aydin C, Uzun O, Topuz O, Alacam T. Evaluation of the surface characteristics of used and new ProTaper instruments:an atomic force microscopy study. Journal of Endodontics. 2007;33(11):1334-7.
G Ametrano, V D'Antò, M P Di Caprio, M Simeone, S Rengo, G Spagnuolo. Effects of sodium hypochlorite and EDTA on rotary nickel-titanium instruments evaluated using atomic force microscopy. International Endodontic Journal. 2011;44(3):203-9.
Pirani C, Paolucci A, Ruggeri O, Bossù M, Polimeni A. Cyclic fatigue testing and metallographic analysis of nickel-titanium rotary instruments. Journal of Endodontics. 2011;37(7):1013-6.
Martins RC, Bahia MGA, Buono VTL. Surface analysis of ProFile instruments by scanning electron microscopy and X- ray energy-dispersive spectroscopy:a preliminary study. International Endodontic Journal. 2002;35(10):848-53.
Peters OA, Roehlike JO, Baumann MA. Effect of immersion in sodium hypochlorite on torque and fatigue resistance of nickel-titanium instruments. Journal of Endodontics. 2007;33(5):589-93.
Berutti E, Chiandussi G, Gaviglio I, Ibba A. Influence of sodium hypochlorite on fracture properties and corrosion of ProTaper rotary instruments. International Endodontic Journal. 2006;39(9):693-9.
Fayyad DM, Mahran AH. Atomic force microscopic evaluation of nanostructure alterations of rotary NiTi instruments after immersion in irrigating solutions. International Endodontic Journal. 2014;47(6):567-73.
Topuz O, Aydin C, Uzun O, Alacam T, Inan U. Structural effects of sodium hypochlorite solution on RaCe rotary NiTi instruments:an atomic force microscopy study. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology. 2008;105(5):661-5.
Sonntag D, Peters OA. Effect of prion decontamination protocols on nickel-titanium rotary surfaces. Journal of Endodontics. 2007;33(4):442-6.
Erik CE, Özyürek T. Effects of etidronate, NaOCl, EDTA irrigation solutions and their combinations on cyclic fatigue resistance of nickel-titanium single-file rotary and reciprocating instruments at body temperature. Odontology. 2019;107(2):190-5.
Upendran A, Gupta R, Geiger Z. Dental infection control. StatPearls [Internet]. Treasure Island (FL):StatPearls Publishing;2021 Jan.
Razavian H, Shokouhinejad N, Jalali S, Khoshbin E, Mohammadi Z. Effect of autoclave cycles on surface characteristics of S-files evaluated by scanning electron microscopy. Iranian Endodontic Journal. 2016;11(1):29-33.
Nair AS, Tilakchand M, Naik BD. The effect of multiple autoclave cycles on the surface of rotary NiTi endodontic files:an in vitro atomic force microscopy investigation. Journal of Conservative Dentistry. 2015;18(3):218-22.

Details

Primary Language

English

Subjects

Dental Materials and Equipment, Endodontics

Journal Section

Research Article

Authors

Enes Elmali
0000-0001-5594-6643
Türkiye

Faruk Oztekin ^*
0000-0002-5131-0063
Türkiye

Publication Date

August 31, 2026

Submission Date

November 3, 2025

Acceptance Date

April 20, 2026

Published in Issue

Year 2026 Volume: 6 Number: 2

DOI

https://doi.org/10.61139/ijdor.1816822

IZ

https://izlik.org/JA64SN67LT

Cite

RIS / Bibtex

APA

Elmali, E., & Oztekin, F. (2026). The Effect of Sterilization Procedures and Different Irrigation Solutions on Surface Roughness of Nickel-Titanium Files: An Atomic Force Microscopy Study. HRU International Journal of Dentistry and Oral Research, 6(2), 73-80. https://doi.org/10.61139/ijdor.1816822

AMA

1.Elmali E, Oztekin F. The Effect of Sterilization Procedures and Different Irrigation Solutions on Surface Roughness of Nickel-Titanium Files: An Atomic Force Microscopy Study. HRU Int J Dent Oral Res. 2026;6(2):73-80. doi:10.61139/ijdor.1816822

Chicago

Elmali, Enes, and Faruk Oztekin. 2026. “The Effect of Sterilization Procedures and Different Irrigation Solutions on Surface Roughness of Nickel-Titanium Files: An Atomic Force Microscopy Study”. HRU International Journal of Dentistry and Oral Research 6 (2): 73-80. https://doi.org/10.61139/ijdor.1816822.

EndNote

Elmali E, Oztekin F (August 1, 2026) The Effect of Sterilization Procedures and Different Irrigation Solutions on Surface Roughness of Nickel-Titanium Files: An Atomic Force Microscopy Study. HRU International Journal of Dentistry and Oral Research 6 2 73–80.

IEEE

[1]E. Elmali and F. Oztekin, “The Effect of Sterilization Procedures and Different Irrigation Solutions on Surface Roughness of Nickel-Titanium Files: An Atomic Force Microscopy Study”, HRU Int J Dent Oral Res, vol. 6, no. 2, pp. 73–80, Aug. 2026, doi: 10.61139/ijdor.1816822.

ISNAD

Elmali, Enes - Oztekin, Faruk. “The Effect of Sterilization Procedures and Different Irrigation Solutions on Surface Roughness of Nickel-Titanium Files: An Atomic Force Microscopy Study”. HRU International Journal of Dentistry and Oral Research 6/2 (August 1, 2026): 73-80. https://doi.org/10.61139/ijdor.1816822.

JAMA

1.Elmali E, Oztekin F. The Effect of Sterilization Procedures and Different Irrigation Solutions on Surface Roughness of Nickel-Titanium Files: An Atomic Force Microscopy Study. HRU Int J Dent Oral Res. 2026;6:73–80.

MLA

Elmali, Enes, and Faruk Oztekin. “The Effect of Sterilization Procedures and Different Irrigation Solutions on Surface Roughness of Nickel-Titanium Files: An Atomic Force Microscopy Study”. HRU International Journal of Dentistry and Oral Research, vol. 6, no. 2, Aug. 2026, pp. 73-80, doi:10.61139/ijdor.1816822.

Vancouver

1.Enes Elmali, Faruk Oztekin. The Effect of Sterilization Procedures and Different Irrigation Solutions on Surface Roughness of Nickel-Titanium Files: An Atomic Force Microscopy Study. HRU Int J Dent Oral Res. 2026 Aug. 1;6(2):73-80. doi:10.61139/ijdor.1816822