Torsional properties of stainless steel Canal Master U and Flexogates

The purpose of this study was to evaluate and compare the torsional properties of Flexogates and Canal Master U instruments. Torsion and bending tests were performed on both designs of instrument according to ANSI/ADA specification number 28 criteria and standards. Ten instruments of each size, sizes 25 to 50 were used for each test. Four parameters were measured: the moment at failure, the rotation at failure, the separation point at failure and the bending moment at a 45 degrees angle. Both instruments satisfied ANSI/ADA standards for rotation at failure and bending moment. Canal Master U satisfied ANSI/ADA standards for moment at failure in all sizes except 45 and 50. Flexogates did not satisfy these standards in all sizes except 50. Flexogates separated at the end of the shaft whereas Canal master U separated just behind the cutting head. Both instruments showed favourable physical properties for preparing root canals.