|About this Abstract
||Materials Science & Technology 2011
||Next Generation Biomaterials
||Next-Generation Rotary Endodontic Instruments Fabricated from Special NiTi Alloy
||William Brantley, Jie Liu, William A.T. Clark, Masahiro Iijima, Libor Kovarik, Fengyuan Zheng, Scott Schricker, Satish Alapati, John Nusstein
|On-Site Speaker (Planned)
Background: Next-generation rotary endodontic instruments with improved clinical performance are being fabricated from special superelastic NiTi wire (termed M-Wire) that has a nanoscale martensitic structure. In this presentation we report etched microstructures, Vickers hardness measurements, and SEM observations of as-manufactured and clinically-used GTŪ Series X™ rotary instruments, with comparisons to rotary instruments fabricated from conventional dental superelastic NiTi alloy. Results: The next-generation NiTi instruments have significantly higher Vickers hardness and much less evidence of clinical wear compared to conventional NiTi instruments. Etched microstructures show a martensitic structure, which is consistent with our previously reported STEM observations. Differential scanning calorimetric analyses have shown that the manufactured instruments have similar phase transformation behavior to starting M-Wire blanks. Conclusions: The properties and clinical performance of the next-generation NiTi rotary instruments arise from their special martensitic structure. More TEM studies are needed to elucidate details of this complex microstructure and effects of clinical use.