Fractographic analysis of twisted file adaptive broken instruments showed signs of flexural fatigue (indicated by the arrows) and in some specimens also torsional fatigue (indicated by the circle).
A = SM3 instrument; B = SM2 instrument.
Gambarini G, Piasecki L, Di Nardo D, Miccoli G, Di Giorgio G, Carneiro E, Al-Sudani D, Testarelli L.
J Oral Maxillofac Res 2016 (Oct-Dec);7(4):e5. doi:10.5037/jomr.2016.7405