Evaluation of the forces that occur during the treatment of different reciprocal rotary instrument systems with finite element analysis

Rotary file systems consisting of nickel titanium (NiTi) alloys with different metallurgical and physical properties are used in root canal shaping which is considered as one of the most important stages of root canal treatment. In this study, it is aimed to evaluate the forces that occur during the treatment of five different rotary file systems and the stresses due to these forces. In the study, Reciproc (VDW, Munich Germany), Reciproc Blue (VDW, Munich, Germany), WaveOne (Dentsply Maillefer, Ballaigues, Switzerland), WaveOne Gold (Dentsply Maillefer, Ballaigues, Switzerland) and Unicone (Medin, Nove Mesto na Morave, Czech Republic) were used; bending, torsional and bending + torsional stress resistance of rotating file systems were evaluated with finite element analysis using Ansys Workbench 2019 R1 program. As a result of the bending tests, the lowest stress value was observed in the Reciproc Blue root canal instrument, followed by WaveOne Gold, WaveOne, Reciproc and Unicone root canal instruments respectively. As a result of the torsion tests, the lowest stress value was found in the WaveOne Gold root canal instrument, whereas the highest stress value was found in the Reciproc root canal instrument. In bending + torsion analysis, the lowest stress value was found in Reciproc Blue root canal instrument and the highest stress value was found in Unicone root canal instrument. As a result, all of the tests showed less stress on instruments with more martensitic properties. Keywords: finite elemet analysis, nickel titanium, stress, bending, torsion