Opto-magnetic imaging spectroscopy in analyzing rotary NiTi endodontic instruments

Area of Science:

• Materials Science
• Biomaterials Engineering
• Dental Materials

Background:

• Intra-canal fracture of nickel-titanium (NiTi) rotary instruments is a common complication in endodontic therapy.
• Fractured instruments impede root canal preparation and negatively impact treatment outcomes.
• Understanding the factors contributing to NiTi instrument failure is crucial for improving dental procedures.

Purpose of the Study:

• To investigate the magnetic properties and ultrastructural changes of new, used, and fractured NiTi instruments.
• To evaluate the effectiveness of opto-magnetic imaging spectroscopy (OMIS) in analyzing these changes.
• To compare the magnetic behavior of different NiTi rotary systems, including electropolished variants.

Main Methods:

• Analysis of three types of rotary NiTi instruments (MTwo, Pro Taper Universal, BioRace) in new, used, and fractured states.
• Utilized opto-magnetic imaging spectroscopy (OMIS) to assess magnetic properties and ultrastructural characteristics.
• Instrumentation was performed on root canals with varying curvatures to induce intra-canal fractures.

Main Results:

• OMIS revealed coincident peak localization for new and used (non-fractured) NiTi instruments.
• Coincident peak intensities were observed between new and fractured NiTi instruments across all groups.
• Electropolishing of BioRace instruments resulted in distinct electromagnetic responses compared to conventional NiTi instruments, with new BioRace instruments showing the most pronounced intensity values.

Conclusions:

• Instrumentation alters the magnetic properties of NiTi rotary instruments.
• OMIS is a valuable tool for detecting changes in NiTi instruments post-use and identifying potential failure indicators.
• Surface treatments like electropolishing significantly influence the magnetic characteristics and performance of NiTi instruments.