title: Finite Element Study on Continuous Rotating versus Reciprocating Nickel-Titanium Instruments.
abstract: In the present study, GTX and ProTaper as continuous rotating endodontic files were numerically compared with WaveOne reciprocating file using finite element analysis, aiming at having a low cost, accurate/trustworthy comparison as well as finding out the effect of instrument design and manufacturing material on its lifespan. Two 3D finite element models were especially prepared for this comparison. Commercial engineering CAD/CAM package was used to model full detailed flute geometries of the instruments. Multi-linear materials were defined in analysis by using real strain-stress data of NiTi and M-Wire. Non-linear static analysis was performed to simulate the instrument inside root canal at a 45° angle in the apical portion and subjected to 0.3 N.cm torsion. The three simulations in this study showed that M-Wire is slightly more resistant to failure than conventional NiTi. On the other hand, both materials are fairly similar in case of severe locking conditions. For the same instrument geometry, M-Wire instruments may have longer lifespan than the conventional NiTi ones. In case of severe locking conditions both materials will fail similarly. Larger cross sectional area (function of instrument taper) resisted better to failure than the smaller ones, while the cross sectional shape and its cutting angles could affect instrument cutting efficiency.
authors.affiliation: Department of Mechanical Engineering, National Research Centre, Giza, Egypt.
authors.forename: Mohamed I
authors.initials: MI
authors.lastname: El-Anwar
authors.affiliation: Department of Restorative Dentistry, Al-Farabi Dental College, Jeddah, KSA and Faculty of Oral and Dental Medicine, Department of Crown & Bridge, Al Azhar University, Assiut, Egypt.
authors.forename: Salah A
authors.initials: SA
authors.lastname: Yousief
authors.affiliation: Department of Restorative and Dental Materials, National Research Centre, Giza, Egypt.
authors.forename: Engy M
authors.initials: EM
authors.lastname: Kataia
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Mansoura university, Mansoura, Egypt.
authors.forename: Tarek M Abd
authors.initials: TM
authors.lastname: El-Wahab
mesh_terms: D003762:Dental Instruments; D020342:Finite Element Analysis; D009532:Nickel / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D009532:Nickel; D014025:Titanium