Ricerc@Sapienza

Introduction: Previously published studies have deeply investigated the characteristics of flexural and torsional resistance of nickel-titanium rotary instruments, but none of them investigated the relationship between the 2 stresses. The objective of the present study was to evaluate the influence of flexural stresses over torsional resistance. Methods: Sixty S-One 20.04 files (Fanta Dental, Shanghai, China) were used in the present study (N = 60) and divided into 3 test groups of 20 files.

Objectives: To evaluate the mechanical properties and metallurgical characteristics of the M3 Rotary and M3 Pro Gold files (United Dental).

Introduction: The aim of the present study is to evaluate the torsional resistance and the operative torque of two different files and to introduce the concept of 'torque range', that indicates the difference between torque at failure and operative torque.