The aim of this study was to evaluate the effect of sterilization on cyclic fatigue resistance and cutting efficiency of Protaper Next (PTN), Pepsi Gold (PG) and Plex V (PV) rotary files.

Methods: For cyclic fatigue resistance testing, 20 files of each type were divided into: nonsterile, underwent one, two and three sterilization cycles. The test was done on a static apparatus in an artificial canal. The number of cycles to failure was calculated for evaluation. For cutting efficiency testing, 10 files of each type were tested nonsterile and after every cycle for three cycles. The test was done on an apparatus that guided the file to cut along a plexiglass sheet. The cut area was measured on a special computer software after one minute of operation.

Results: Cyclic fatigue results showed no significant difference between the sterilized subgroups and the non-sterilized subgroups. PG demonstrated the highest cyclic fatigue resistance among the tested groups followed by PV then PTN. Cutting efficiency results showed a significant difference in PG and PV after one sterilization cycle and use while they showed a significant difference in PTN after the second sterilization cycle and use. PG demonstrated the highest cutting efficiency followed by PTN then PV.

Conclusions: Sterilization has no effect on cyclic fatigue resistance of the tested files. PG has the highest cyclic fatigue resistance followed by PV then PTN. Sterilization and use have a negative effect on the tested files. PG has the highest cutting efficiency followed by PTN then PV.