Date of Award
Master of Science (MS)
Introduction: One important step of root canal therapy is the process of cleaning and shaping each canal. This process involves using endodontic rotary files combined with chemical irrigants to remove pulpal remnants and infected dentin from the canal while eliminating pathogenic bacteria. It is essential to maintain proper canal anatomy while cleaning and shaping. The challenge for the practitioner is to select a rotary file system that will be flexible enough to maintain canal anatomy but strong enough to prevent breakage under normal use. File flexibility allows for better maintenance of canal anatomy. A file’s resistance to torsional fatigue reduces the chance of file breakage. The purpose of this study was to compare the torsion and bending properties of a brand new file system (EdgeFiles by EdgeEndo, Albuquerque, NM) marketed as being twice as strong but half the price compared to other marketed files Materials and Methods: Thirty files of each type were used. Ten different files systems were evaluated. Size 30 files of .04 taper EdgeFile X7, EdgeFile X5, EndoSequence (Brasseler), Vortex Blue (Dentsply), GT Series X (Dentsply), K3XF (SybronEndo), HyFlex CM (Coltene/Whaledent, Inc.), and .06 taper EdgeFile X3 (EdgeEndo), ProTaper Universal (Dentsply), ProTaper Gold (Dentsply). Testing was done with a torsiometer following ISO 3630-1. Twelve of each file type were evaluated for bending and 18 of each type were evaluated with torsion. Results were separated into 3 different groups due to differences in file design. Group 1 included X3, Protaper Universal, and Protaper Gold. Group 2 included X5 and GT series X. Group 3 included X7, EndoSequence, Vortex Blue, K3XF, and HyFlex CM. Results: In Group 1, X3 showed the most flexibility followed by ProTaper Gold then ProTaper Universal. For strength, ProTaper Gold had the highest resistance to torsion followed by ProTaper Universal then X3. In Group 2, X5 showed more flexibility while GTX had higher strength. In Group 3, HyFlex CM showed the most flexibility followed by X7, then EndoSequence, Vortex Blue, and finally K3XF. For strength, K3XF was highest. X7 and Vortex Blue had similar values which were higher than HyFlex CM followed by EndoSequence. Conclusion: An overall conclusion could be made that strength and flexibility have a relatively inverse relationship in each group. The stronger files tend to be less flexible and the more flexible files tend to be more susceptible to torsional failure. ProTaper Gold and X7 had the best combinations of strength and flexibility.