Cleaning efficiency of nickel-titanium GT and .04 rotary files when used in a torque-controlled rotary handpiece

This study determined if the cleaning efficiency of nickel-titanium rotary files in an endodontic electric handpiece using a no-torque control setting was superior to that obtained when using the torque-control feature. Fifty extracted human anterior teeth with straight canals were divided into two groups of 20 and two control groups of 5. Canals were instrumented with GT and .04 ProFile nickel-titanium files until a size 35 advanced to working length. Samples were sectioned and the apical 6 mm of the canal was photographed (x20) and projected onto a 3- x 4-foot grid with squares measuring 0.5 inches each. Total debris was the percentage of the number of squares containing debris versus the total number of squares. The teeth in the torque-controlled group showed an average of 24.99% debris versus 15.55% for the teeth in the no-torque group. The difference was not statistically significant; therefore, no difference can be said to exist between the two torque settings in terms of cleaning efficiency.