Comparison of binary, ternary, quaternary SMAs in Endodontic Applications

NiTi-based Shape Memory Alloys (SMA) find wide applicability in engineering sectors, including automotive, aerospace, and the biomedical field. In this work, we focus on the endodontic applications in medical industry. The main advantage of using NiTi alloys in root canal treatment instruments is the alloy’s high flexibility. Superelasticity is characterized by a significant reversible deformation occurring while the stress remains constant (plateau), based on a stress-induced martensitic transformation. Within the scope of this work, we provide a review of binary, ternary, and quaternary alloys exhibiting superelasticity and shape memory effect, and compare them in terms of transformation temperatures and mechanical properties, with a focus on their applications in endodontics. A comparison of how these properties of NiTi, NiTiX and NiTiXY (X,Y=Cu, Cr, V, and other elements) wire can be utilized for root canal wires without undergoing irreversible deformation or breakage during insertion into the root canal. The inclusion of additional alloying elements in quaternary SMAs enables more precise control over the phase transformation and mechanical properties. Besides the reduction in hysteresis, improving the efficiency and performance of the shape memory effect are enhanced. We will provide comprehensive data, including mechanical properties, DSC measurements and fatigue test results.