Effect of sodium hypochlorite and saline on cyclic fatigue resistance of WaveOne Gold and Reciproc reciprocating instruments

Abstract

Immersion of WaveOne Gold and Reciproc reciprocating instruments in saline and NaOCl solutions decreased considerably their cyclic fatigue resistance. The fatigue resistance of WaveOne Gold instruments was higher than that of Reciproc instruments.

A critical appraisal of studies on cyclic fatigue resistance of engine‐driven endodontic instruments

“…Furthermore, to a certain extent the use of different lubricants during testing may be responsible for the inconsistent results (Elnaghy & Elsaka , Uslu et al ). When assessing Reciproc instruments in air fracture occurred after 1251 cycles, in sodium hypochlorite it occurred after only 882 cycles (Elnaghy & Elsaka ). This difference is nearly 250%.…”

“…A 100% increase in speed has been demonstrated to result in a 30% reduction in terms of NCF (Lopes et al 2009). Furthermore, to a certain extent the use of different lubricants during testing may be responsible for the inconsistent results (Elnaghy & Elsaka 2017b. When assessing Reciproc instruments in air fracture occurred after 1251 cycles, in sodium hypochlorite it occurred after only 882 cycles (Elnaghy & Elsaka 2017b).…”

“…Whilst a constant diameter of the tube of 1.4–2 mm was described in the majority of the studies, the tube was designed to reproduce the instrument size in several other investigations (Plotino et al , , Gambarini et al , Pedulla et al , Elnaghy & Elsaka ,b, Yilmaz et al ). This variability may have an impact on the obtained results as tube sizes imitating the instrument size are prone to include torsional fatigue into the cyclic fatigue model, whilst loose tube designs may focus on the cyclic fatigue evaluation, but suffer from missing a constant trajectory of the loosely inserted instruments (Plotino et al ).…”

New thermomechanically treated NiTi alloys – a review

“…DSC analysis of ProTaper Gold revealed approximately 50°C for austenite finish temperature (Hieawy et al 2015), indicating that these instruments also mainly contain martensite or Rphase under clinical conditions. All Gold and Blue heat-treated files demonstrated enhanced flexibility and fatigue resistance compared with conventional NiTi and M-Wire instruments , Nguyen et al 2014, Plotino et al 2014b, 2017Duke et al 2015, Hieawy et al 2015, Elnaghy & Elsaka 2016a, 2017a, Kaval et al 2016 Kaval et al (2016) reported that ProTaper Gold had a significantly higher maximum torque than Hyflex EDM and ProTaper Universal (Dentsply Sirona Endodontics), whilst Hyflex EDM had an increased distortion angle. ProTaper Gold was found to be more effective in lateral cutting action than ProTaper Universal (Vasconcelos et al 2018).…”

Effect of interrupted motion on the cyclic fatigue resistance of reciprocating nickel–titanium instruments

“…During instrumentation, interruption of file movement within a root canal could occur in several clinical scenarios (Elnaghy & Elsaka 2016). Electronic apex locator integrated endodontic motors stop the instrument when the working length is reached to prevent over instrumentation (Siu et al 2009).…”