Cyclic Fatigue Fracture Resistance Evaluation of Three NiTi Rotary Multiple File Systems: An in-vitro Comparative Study

Background: This in-vitro study used cyclic fatigue testing device to compare the cyclic fatigue fracture resistance of three rotary multiple file system; Neoendo flex, Hanu Dent and Hero Gold.

Place and Duration of Study: Between November 2022 and January 2023 in Department of Conservative Dentistry and Endodontics at the Institute of Dental Sciences Sehora in Jammu, Union Territory of Jammu and Kashmir.

Methodology: In this research three rotary nickel titanium systems Neoendo flex, Hanu Dent and Hero Gold; Micromega of size #25 with 4% taper were subjected to cyclic fatigue testing. Each system contained ten files which were 25 mm long. Each experimental file had EDTA gel applied to it before being put into endodomotor handpiece with rubber stopper. The dental hand piece was attached to portable device making it easy to insert each instrument inside the artificial canal. The files were working in the artificial canal as long as fracture occurred. The number of cycles until fracture was then calculated using the time. NCF = Number of rotations per minute x Time to fracture.

Results: Hero Gold was followed by Hanu Dent in terms of mean values for the number of seconds to fracture. When utilized in curved canals, Neoendo Flex showed least resistance to cyclic fatigue fracture.

Clinical Significance: To endodontists, the choice of file systems in cleaning and shaping of root canal is a mystery. This in vitro study investigated the choice of rotary root canal preparation file systems. NiTi endodontic files that have undergone heat treatment have dramatically enhanced the cyclic fatigue résistance extending the average life of file systems.