@article{Bhat_Kini_Shetty_Kansara_Penugonda_2022, title={Cyclic Fatigue Resistance and Surface Roughness of Rotary NiTi Instruments after Simulated Clinical Use in Curved Root Canals – An Atomic Force Microscopy Study}, volume={22}, url={https://revista.uepb.edu.br/PBOCI/article/view/1346}, abstractNote={<div><strong><span lang="EN-US">Objective: </span></strong><span lang="EN-US">To examine the cyclic fatigue resistance and surface topography of TruNatomy and ProTaper Gold nickel-titanium rotary files and evaluate the presence of alterations to surface topography following instrumentation in simulated curved canals</span><span lang="EN-US">. </span><strong><span lang="EN-US">Material and Methods: </span></strong><span lang="EN-US">Twenty-four nickel-titanium instruments, twelve each of TN and PTG file systems, were evaluated for cyclic fatigue resistance. The rotary files were rotated in a simulated root canal with standardized diameter, angle of curvature, and radius of curvature in a custom-made cyclic fatigue testing device until the instrument fracture occurred. The time to fracture for each instrument was recorded with a stopwatch; in seconds in each group. Fractured instruments were subjected to atomic force microscopy analysis measuring the average roughness and the root mean square values to investigate surface features of endodontic files. Mean values and standard deviation were calculated. Data were analyzed using the Mann-Whitney U test. </span><strong><span lang="EN-US">Results: </span></strong><span lang="EN-US">Time to fracture was marginally higher in PTG instruments than in the TN file systems. PTG files exhibited higher surface roughness when compared with TN files (p<0.05)</span><span lang="EN-US">. </span><strong><span lang="EN-US">Conclusion: </span></strong><span lang="EN-US">TN file system had a higher cyclic fatigue resistance than PTG. Cyclic fatigue causing file breakage did affect the surface topography of the files. PTG files showed a higher surface porosity value than the TN files.</span></div>}, journal={Pesquisa Brasileira em Odontopediatria e Clínica Integrada}, author={Bhat, Raksha and Kini, Arjun and Shetty, Preethesh and Kansara, Payalben and Penugonda, Bapanaiah}, year={2022}, month={Jul.}, pages={e210120} }