Effect of the sterilization on the cutting efficiency of ProTaper and K3 endodontic instruments

Objective: This objective of this study was to evaluate the effect of sterilization on the cutting efficiency of rotary endodontic instruments, ProTaper (Dentsply Maillefer Instruments S.A., Ballaigues, Suí a) and K3 (Sybron/Kerr, Orange, CA, USA), by the time X weighing method. Method: For this purpose, 60 simulated canals and 66 instruments were used (36 of the ProTaper system, (Dentsply Maillefer Instruments S.A., Ballaigues, Switzerland) and 30 of the K3 system (Sybron/Kerr, Orange, CA, USA). The rotary instruments were divided into four experimental groups. The instruments in Group A (K3 , Sybron/Kerr, Orange, CA, USA) and Group B (ProTaper , Dentsply Maillefer Instruments S.A., Ballaigues, Switzerland), were subjected to a process of cleaning and sterilization. Whereas the instruments in Group C (K3 , Sybron/Kerr, Orange, CA, USA) and Group D (ProTaper , Dentsply Maillefer Instruments S.A., Ballaigues, Switzerland), were subjected to the cleanness process only, and were not sterilized. Results: As regards analysis of the results, the Student’s-t test was used, by which it was verified that the instruments in Group had greater cutting efficiency in comparison with those in Group B. Similarly the instruments in Group C had greater cutting efficiency in comparison with those in Group D, nevertheless, there was no statistically significant difference. Moreover, as regards the number times of use, there was also no statistically significant difference between the experimental groups. However in all the groups there was a decrease in the cutting efficiency with an increasing number of times of use. Conclusion: Thus, the cutting efficiency of rotary endodontic instruments K3 (Sybron/Kerr, Orange, CA, USA) and ProTaper (Dentsply Maillefer Instruments S.A., Ballaigues, Sui o) was not statistically affected after the use of 6 autoclave sterilization cycles.