One of the primary goals in endodontics is efficient cleaning and shaping of the root canal while maintaining its original configuration. Numerous studies highlight the advantage of using nickel-titanium instruments and the most important is their high flexibility and the ability to penetrate the curved canals. The aim of this study was to analyze the ultrastructure of the surface of nickel-titanium endodontic files before and after use. Eighty-four instruments were included in this study. The instruments were used one, three and six times for root canal preparation on extracted upper premolars. The analysis was performed based on the number of uses and the size of the instruments. Changes on flat surfaces in the grooves of the instruments, defects of the cutting edges and fractures were evaluated. The surface ultrastructure was analyzed on a scanning electron microscope (SEM). SEM analysis showed irregularities on the surfaces of the new instruments. Surface defects and damage of the cutting edges were present after the first use. After three uses, the damage was more evident in instruments of all sizes. After six uses, all instruments showed damage of the cutting edges, and a significant number of fractures were observed. Irregularities on the working parts are already noticed on the new endodontic instruments and originate from the production process. The first signs of damage appear after the first use. In order to prevent errors in clinical work during root canal preparation, it is recommended that the number of instruments uses should be limited.
References
1.
ALAPATI S, BRANTLEY W, SVEC T, POWERS J, MITCHELL J. Scanning Electron Microscope Observations of New and Used Nickel-Titanium Rotary Files. Journal of Endodontics. 2003;29(10):667–9.
2.
Casella G, Rosalbino F. Corrosion behaviour of NiTi endodontic instruments. Corrosion Engineering, Science and Technology. 2011;46(4):521–3.
3.
Spagnuolo G, Ametrano G, D’Antò V, Rengo C, Simeone M, Riccitiello F, et al. Effect of autoclaving on the surfaces of <scp><scp>TiN</scp></scp>‐coated and conventional nickel–titanium rotary instruments. International Endodontic Journal. 2012;45(12):1148–55.
4.
Logsdon J, Dunlap C, Arias A, Scott R, Peters OA. Current Trends in Use and Reuse of Nickel-Titanium Engine-driven Instruments: A Survey of Endodontists in the United States. Journal of Endodontics. 2020;46(3):391–6.
5.
Filho IB, Esberard RM, Leonardo R de T, del Rio CE. Microscopic evaluation of three endodontic files pre- and postinstrumentation. Journal of Endodontics. 1998;24(7):461–4.
6.
Thompson SA. An overview of nickel–titanium alloys used in dentistry. International Endodontic Journal. 2000;33(4):297–310.
7.
Luzi A, Forner L, Almenar A, Llena C. Microstructure alterations of rotary files after multiple simulated operative procedures. Medicina Oral Patología Oral y Cirugia Bucal. 2010;e658–62.
8.
Fišerová E, Chvosteková M, Bělašková S, Bumbálek M, Joska Z. Survival Analysis of Factors Influencing Cyclic Fatigue of Nickel-Titanium Endodontic Instruments. Advances in Materials Science and Engineering. 2015;2015:1–6.
9.
Vieira EP, Nakagawa RKL, Buono VTL, Bahia MGA. Torsional behaviour of rotary NiTi ProTaper Universal instruments after multiple clinical use. International Endodontic Journal. 2009;42(10):947–53.
10.
Plotino G, Grande NM, Cordaro M, Testarelli L, Gambarini G. A Review of Cyclic Fatigue Testing of Nickel-Titanium Rotary Instruments. Journal of Endodontics. 2009;35(11):1469–76.
11.
Chianello G, Specian VL, Hardt LCF, Raldi DP, Lage-Marques JL, Habitante SM. Surface finishing of unused rotary endodontic instruments: a SEM study. Brazilian Dental Journal. 2008;19(2):109–13.
12.
Yamazaki‐Arasaki AK, Cabrales RJS, Kleine BM, Araki ÂT, Dos Santos M, Prokopowitsch I. Qualitative analysis of files of four different rotary systems, before and after being used for the twelfth time. Microscopy Research and Technique. 2013;76(1):79–85.
13.
Elmsallati EA, Wadachi R, Ebrahim AK, Suda H. Debris retention and wear in three different nickel‐titanium rotary instruments. Australian Endodontic Journal. 2006;32(3):107–11.
14.
Y PR. Cyclic Fatigue Testing of Three Different Rotary Nickel Titanium Endodontic Instruments in Simulated Curved Canals - An in Vitro Sem Analysis. JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH.
15.
Hülsmann M, Donnermeyer D, Schäfer E. A critical appraisal of studies on cyclic fatigue resistance of engine‐driven endodontic instruments. International Endodontic Journal. 2019;52(10):1427–45.
16.
Guelzow A, Stamm O, Martus P, Kielbassa AM. Comparative study of six rotary nickel–titanium systems and hand instrumentation for root canal preparation. International Endodontic Journal. 2005;38(10):743–52.
17.
Zuolo MI, Walton RE. Instrument deterioration with usage: nickel titaniun versus stainless steel. Quintessence Int. 1997;28:397–402.
18.
Orhan EO, Ertuğrul İF. Cyclic fatigue life of novel rotary compactors: A scanning electron microscopy evaluation. Microscopy Research and Technique. 2020;83(1):66–71.
19.
PETERS O. Current Challenges and Concepts in the Preparation of Root Canal Systems: A Review. Journal of Endodontics. 2004;30(8):559–67.
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