Cyclic Fatigue Resistance of Nickel-Titanium Reciprocating Instruments after Simulated Clinical Use

Author(s)

Duque, Jussaro Alves ; Bramante, Clovis Monteiro ; Hungaro Duarte, Marco Antonio ; Alcalde, Murilo Priori ; Nogueira Leal Silva, Emmanuel Joao ; Vivan, Rodrigo Ricci

• Document type: Journal article
• Source: JOURNAL OF ENDODONTICS; v. 46, n. 11, p. 5-pg., 2020-11-01.

Abstract

Introduction: The aim of this study was to evaluate the cyclic fatigue resistance of different heat-treated nickel-titanium reciprocating instruments in 2 different situations: new and used instruments after preparing 3 curved canals. Methods: A total sample of 60 nickel-titanium instruments of 3 systems (n = 20 per system) were used in this study: ProDesign R (tip 25, 0.06 taper; Easy Dental Equipment, Belo Horizonte, Brazil), Reciproc Blue (tip 25, 0.08v taper; VDW, Munich, Germany), and WaveOne Gold (tip 25, 0.07v taper; Dentsply Sirona, Ballaigues, Switzerland). Thirty new instruments (n = 10 per system) were used to prepare 90 curved single-rooted mandibular premolars (n = 30). Each instrument was used to prepare 3 root canals, and after each canal preparation the instrument was ultrasonic cleaned and submitted to autoclave sterilization procedures. The other 30 instruments (n = 10 per system) were kept without use. Then, the new and used instruments were subjected to the cyclic fatigue test in an artificial canal with a 30 degrees angle and a 5-mm radius of curvature. The time and number of cycles to fatigue were recorded. Data were analyzed using the unpaired t test for intragroup comparison. For intergroup comparison, analysis of variance and the Tukey test for multiple comparisons were used. Results: The intergroup comparison of new instruments showed that ProDesign R had the highest cyclic fatigue resistance followed by Reciproc Blue and WaveOne Gold (P < .05). Regarding the used instruments, WaveOne Gold had the lowest cyclic fatigue resistance (P < .05). The intragroup comparison between new and used instruments showed that WaveOne Gold and ProDesign R presented a significant reduction in the cyclic fatigue resistance after simulated clinical use (P < .05); no difference was found with the Reciproc Blue instruments (P > .05). Conclusions: ProDesign R had the highest cyclic fatigue resistance, whereas WaveOne Gold had the lowest for new and used instruments. Simulated clinical use affected the cyclic fatigue resistance of ProDesign R and WaveOne Gold but not of Reciproc Blue instruments. (AU)

• FAPESP's process: 16/19956-5 - Quality analysis of the preparation and retreatment of different instruments associated or not to different protocols agitation irrigant
• Grantee: Jussaro Alves Duque
• Support Opportunities: Scholarships in Brazil - Doctorate