Fatigue Life of ProTaper GoldRM Instruments

Introduction: The purpose of this study was to characterize the fatigue resistance of the recently introduced ProTaper Gold RM system (PTG; Dentsply Tulsa Dental Specialities, Tulsa, OK) and to compare it with fatigue resistance of Protaper ® Universal (PTU; Dentsply/Maillefer, Ballaigues, CH) and Protaper Next TM files (PTN; Dentsply/Maillefer, Ballaigues, CH). Materials and Methods: A mechanical device that simulated a root canal system with a radius of curvature of 4.7 mm and an angle of curvature of 45˚ was used to perform the rotational bending tests. Sizes F2/X2 and F3/X3 of PTG, PTU and PTN instruments constituted 6 experimental groups that were analyzed within a rotational speed of 300 rpm and torque of 4 N.cm. Time to fracture and number of cycles to fracture (NCF) were recorded and statistical analysis was carried out using IBM SPSS software. Results: PTG F2 group showed higher NCF than PTU F2 and PTN X2 groups. Concerning F3/X3 instruments, the same tendency could not be stated: NCF of PTG F3 group was statistically higher than PTU F3, but lower than PTN X3. Conclusions: PTG system has proven to be more fatigue resistant than PTU. However, when PTN fatigue resistance concerns, it depends on the type of instruments and its diameter. During clinical practice, clinicians should be aware of this property in order to make an informed choice. Parole chiave: ProTaper Gold, ProTaper Universal, ProTaper Next, fatigue resistance, nickel-titanium instruments