ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

for Mtwo is explained by the high dispersion found in the experimental results and the
fact that after 40° of rotation the instrument already starts to undergo plastic
deformation. Thus, the simulated results after this point are not reliable as discussed
previously.
6. CONCLUSIONS
The flexibility and torsional strength of ProTaper F1 and Mtwo rotary instruments were
assessed by finite element analyses and compared to experimental results following the
specification ISO 3630-1. Based on the results obtained, it was concluded that the
geometric differences between the two types of instruments defined the higher
flexibility of the Mtwo instrument. Nevertheless, for the same reason, the torsional
strength of the Mtwo instrument was lower than the F1 strength. The comparison
among the simulated results and experimental ones reached a good accordance, with the
both approaches indicating the same mechanical behavior of the instruments, meaning
that this finite element model can be employed to study the endodontic instruments.
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