Enhanced cyclic fatigue resistance in endodontic rotary instruments: challenges and innovations

Abstract

Background: Root canal cleaning and shaping are crucial in endodontic treatment, but curved root canals present challenges. Nickel-titanium (NiTi) rotary devices have transformed this surgery due to their shape memory and super-elastic nature. However, cyclic fatigue remains a major issue, causing microfractures in the metal matrix. NiTi alloys' fatigue resistance has been improved through design, manufacturing processes, and thermomechanical processing. CM-Wire's NiTi alloys show potential due to heat-treated NiTi. Cyclic fatigue resistance is influenced by file form, rotation speed, and canal curvature. The irrigation usage of sodium hypochlorite (NaOCl) during instrumentation can also impact file performance. Aim: This work intends to investigate, by means of design modifications, manufacturing procedures, and environmental variables, the cyclic fatigue resistance of existing NiTi rotary instruments under different conditions. This study aims to maximize endodontic techniques and enhance patient outcomes by means of comparison of results of current studies. It will stress the benefits and drawbacks of numerous file systems. generally speaking. Conclusion: Particularly in devices using novel thermomechanical processing and heat treatment, recent improvements have greatly enhanced the cyclic fatigue resistance of NiTi rotary instruments. Protaper Gold, Reciproc Blue, and HyFlex EDM are among the file systems shown to be most successful. The intricacy of optimal file performance is highlighted by the effects of canal curvature, operational factors, and environmental conditions—such as temperature changes and NaOCl exposure. These modifications have not addressed cycle weariness, a problem particularly problematic in too curved canals. Future research should keep searching for creative manufacturing technologies and design ideas that increase the durability and efficiency of NiTi rotary instruments thereby enhancing clinical results and reducing the risk of instrument separation.