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Published on: December 14, 2011
Failure of ProFile instruments used with high and low torque motors
G M Yared1, F E Bou Dagher, P Machtou
1Discipline of Endodontics, Faculty of Dentistry, University of Toronto, Canada. g.yared@utoronto.ca
Aim:
The purpose of this study was to evaluate the failure incidence of ProFile nickel-titanium rotary instruments when used in conjunction with different motors and a specific instrumentation technique.
Methodology:
ProFile Ni-Ti rotary instruments (PRI) with 0.06 taper were used in a crown-down technique. In groups 1, 2 and 3, an air, a high torque and a low torque motor were used, respectively. Each group included 30 canals in extracted human molars. One set of PRI sizes 40-15 was used for each canal; they were sterilized before each case. A 2.5% NaOCl solution was used as an irrigant. The number of deformed and separated instruments was recorded for the various experimental groups.
Results:
Instrument separation did not occur in any of the three groups. One and two instruments were deformed when using the air and high torque motors, respectively.
Conclusions:
The results indicated no difference between the three motors with respect to the incidence of instrument failure. The results suggest that the use of PRI in a crown-down manner with air control motors was safe.
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