1 Lecturer, Yenepoya Dental College, Yenepoya (Deemed To Be University), Mangalore, Karnataka, India. Orcid Id: 0000-0002-4537-8440
2 Reader, Yenepoya Dental College, Yenepoya (Deemed To Be University), Mangalore, Karnataka, India. Orcid Id: 0000-0001-8014-2372
3 Lecturer, Yenepoya Dental College, Yenepoya (Deemed To Be University), Mangalore, Karnataka, India. Orcid Id: 0000-0002-3359-2183
Aim. This review aims to compare the flat-sided nickel-titanium rotary instruments to conventional non-flat-sided instruments in terms of mechanical properties and clinical effectiveness in conventional endodontic practices.
Materials and Methods. A systematic search was conducted across multiple databases, including scopus, pubmed, web of science, and google scholar. Additionally, a manual review of the grey literature was carried out to identify relevant articles. A thorough full-text review was conducted to verify eligibility after titles and abstracts were filtered against predetermined inclusion and exclusion criteria.
Results. Nickel-titanium files with a flat-sided design have, in recent years, drawn attention from both researchers and clinicians. These files, which were first introduced in 2015, feature a distinctive flat-sided shape and provide several benefits over their counterparts. Evidence suggests this modification significantly enhances mechanical flexibility and increases resistance to cyclic fatigue without compromising cleaning and shaping efficiency. However, the lack of standardization and the shortage of longer study protocols pose challenges to its widespread adoption.
Conclusion. Although flat-sided niti rotary instruments show great promise for improving canal morphology and reducing torsional stress, conflicting data about debris removal and biofilm eradication limit their clinical superiority. Additionally, there is conflicting evidence regarding their resistance to cyclic fatigue in the current literature. Thus, to confirm their long-term effectiveness and dependability, thorough in vivo studies and long-term clinical trials are essential.
Keywords: Nickel Titanium, Root Canal Preparation, Metallurgy, Biomechanical Preparation, Cyclic Fatigue.
Source of support: None.
Conflict of interest: None.
How To Cite This Article: Harikrishnan N, Bhat Sr, Anthony Jm. Mechanical Properties And Clinical Efficacy Of Flat-Sided Nickel-Titanium Rotary Instruments: A Narrative Review. Int J Drug Deliv Technol. 2026;16(4):446-450. Doi: 10.25258/ijddt.16.4.44