Structural Analysis of NiTi Endodontic Instruments: A Systematic Review

Area of Science:

• Materials Science
• Biomaterials Engineering
• Dental Materials

Background:

• Nickel-titanium (NiTi) endodontic instruments are prone to structural defects from manufacturing, leading to in-office fracture.
• Fracture incidence necessitates understanding instrument wear and failure mechanisms through structural analysis.
• Existing research utilizes various destructive and non-destructive methods to examine NiTi instrument surfaces and internal structures.

Purpose of the Study:

• To systematically review and analyze methods for evaluating the surface and internal microstructure of endodontic NiTi instruments.
• To identify the most effective structural analysis techniques for NiTi endodontic files.

Main Methods:

• A comprehensive systematic literature search was conducted in major databases (MEDLINE, Web of Science, Cochrane, Scopus, LILACS/BBO) up to June 2019.
• Eligibility criteria followed the PICO strategy, focusing on endodontic instruments and methods for structural analysis of NiTi instruments.
• The systematic review adhered to the PRISMA statement guidelines.

Main Results:

• Ninety-four articles met the inclusion criteria for the review.
• While various methods exist for qualitative/quantitative structural analysis, no single study evaluated both surface and internal structures concurrently.
• Each method demonstrated limitations in analyzing either the surface or internal structure comprehensively.

Conclusions:

• A need exists to compare different methodologies for structural analysis of NiTi endodontic instruments.
• The reliability and limitations of employed methods for structural analysis were revealed, aiding in validity determination.
• Current methods are insufficient for a complete assessment of NiTi instrument structural integrity.