Open AccessDeformation of Nickel-Titanium (NiTi) rotary instruments in cyclic loading – in vitro study
Author(s) -
Isidora Nešković,
Igor Stojanac,
Sanja Vujkov,
Jovan Laban Terzija,
Aleksandra Maletin
Publication year - 2018
Publication title -
stomatološki glasnik srbije
Language(s) - English
Resource type - Journals
eISSN - 1452-3701
pISSN - 0039-1743
DOI - 10.2478/sdj-2018-0006
Subject(s) - nickel titanium , root canal , dental instruments , torque , cyclic stress , orthodontics , dentistry , materials science , metallurgy , medicine , shape memory alloy , physics , thermodynamics
Summary Introduction Separation of instruments in the root canal is one of the challenges in endodontic treatment. More specifically, nickel-titanium (NiTi) rotary instruments usually separate without previous deformation. The aim of this pilot study was to assess the effect of torsional stress on endodontic NiTi rotary instruments separation in simulated clinical conditions. Materials and methods Research was conducted on a sample of 20 human teeth in laboratory conditions. Experimental procedure consisted of determining canal curvatures for each root on digital radiographs and root canal treatment using endodontic NiTi rotary instruments. Out of 20 teeth (60 canals), two groups were formed with similar root canal curvatures (10 pairs of teeth) and instrumented using NiTi rotary instrument with or without torque control. Results Wilcoxon matched pair test showed no statistically significant difference in average number of instruments use with or without torque control (p>0.05). Conclusion Even though there is no statistical significance in instrument separation when instruments were used with or without torque, there is tendency to experience sudden fracture of instruments after work without torsional control even after only few uses in clinical work.