The most demanding working conditions were observed in canals with sharp curves, especially in areas where the instruments had larger diameters. To prevent possible damage to instruments and fracture, it is advised that the instruments should be discarded following their use in such canals.

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The expectations, attitudes, engagement, and motivation of students are key elements when designing learning activities. Several studies have been implemented and different strategies and activities have been analyzed to improve the aforesaid aspects of learning content. In the context of the New Learning Context (NLC), this paper presents the findings of two first day of class activities aimed at engaging engineering students in a business and management subject from the very first moment: an empirical study conducted by means of a survey answered by engineering students in Information and Communication Technologies (ICT), followed by an interactive activity between students and instructors carried out through a reciprocal interview activity. The survey was performed with the objective of identifying what they ‘liked’ and ‘disliked’ on their first day of class of a business subject. The findings are presented and compared with previous studies and have proven to be mostly consistent with previous academic work. Finally, a reciprocal interview activity was chosen to potentially enhance the students’ engagement and motivation. According to the feedback received, this activity was positively valued by the students.

Ni-Ti rotary endodontic instruments (files) are used in dentistry during the endodontic treatment to shape the root canal of the tooth while removing the pulp when infected. Up to now, the studies for evaluating their performances and drawbacks were mainly limited to experimental tests on product flexural and torsional resistance. This work exploits computational analyses for investigating the effects of materials with different mechanical properties on the behavior of rotary endodontic instruments. The aim is to understand the appropriate material choice to reduce the criticality of the treatment in particular clinical conditions. In particular, the interaction between an accurately modeled rotating file and differently shaped root canals during the clinical procedure was studied performing finite element analyses. Strains induced by the treatment on a file made of a ''standard'' Ni-Ti alloy (characterized by average properties of the pseudoelastic behavior), a ''long'' Ni-Ti alloy (characterized by wide transformation region), a ''super'' Ni-Ti alloy (characterized by an extended Hookian behavior without transformation region), and stainless steel were compared. The results accurately show the advantages of the use of Ni-Ti alloy with respect to stainless steel and the better performance of the ''long'' alloy in all the tested case.