Analysis of Cutting Capacity, Surface Finishing, and Mechanical Properties of NiTi Instruments 25/.04: ROTATE and LOGIC 2

J Endod. 2024 Jul;50(7):982-988. doi: 10.1016/j.joen.2024.03.008. Epub 2024 Mar 25.

Abstract

Introduction: In an effort to enhance the quality of mechanized endodontic instruments, various thermal treatment methods, and design modifications have been suggested. However, upon evaluation, these endodontic instruments may exhibit microscopic irregularities. The objective of this in vitro study was to analyze the cutting capacity, surface finish, and mechanical properties of Nickel-Titanium 25/.04 Rotate (VDW GmbH, Munich, Germany) and LOGIC 2 (Easy Equipamentos Odontológicos, Belo Horizonte, MG, Brazil) rotary instruments.

Methodology: Twenty rotary instruments were divided into 2 groups: GR, the group with ROTATE instruments (n = 10); and GL2, the group with LOGIC 2 instruments (n = 10). They were evaluated for roughness, using a profilometer, for bending resistance, buckling resistance, and cutting capacity using a universal testing machine, as well as for torsional strength (torque and angular deflection) using a torquemeter. The instruments were visualized before and after the mechanical tests through scanning electron microscopy.

Results: GR showed better surface finish in terms of roughness, greater cutting capacity, and greater angular deflection than GL2 (P < .05). However, GL2 showed better flexibility than GR (P < .05). GL2 and GR did not show statistically significant differences in terms of buckling and torque (P > .05).

Conclusion: The ROTATE and LOGIC 2 rotary instruments differed in their surface finish, cutting capacity, and mechanical properties, except for their buckling resistance and required fracture torque.

Keywords: Mechanical properties; rotary instruments; roughness; surface finish; torsional fatigue.

MeSH terms

  • Dental Instruments
  • Dental Stress Analysis
  • Equipment Design
  • Materials Testing
  • Microscopy, Electron, Scanning
  • Nickel* / chemistry
  • Root Canal Preparation* / instrumentation
  • Surface Properties*
  • Titanium* / chemistry
  • Torque

Substances

  • Nickel
  • Titanium
  • titanium nickelide