Related Experiment Video
Updated: Aug 17, 2025
Scanning Electron Microscopic Evaluation of Surface Defects of Remover Retreatment File After Single and Multiple Uses
Published on: October 11, 2024
Performance and efficacy of a recently introduced diamond rotary instrument: Cutting, surface preparation, and
Taiseer A Sulaiman1, Tariq Alsahafi2, Shannon M Wallet3
1Associate Professor, Division of Comprehensive Oral Health, Adams School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC.
Statement Of Problem:
Evaluation of the cutting efficiency and effectiveness, surface roughness, and cleanability of a novel rotary instrument is lacking.
Purpose:
The purpose of this in vitro study was to compare the cutting efficiency and effectiveness of a recently introduced diamond rotary instrument containing corundum microspheres with conventional instruments by evaluating the heat generated, surface roughness, and cleanability of each instrument after tooth preparations.
Material And Methods:
Sound molars (n=225) were used to evaluate cutting efficiency and effectiveness by measuring the heat generated by 3 diamond dental rotary instruments: test instrument (TI), reference instrument (RI), and NTI instrument (NI). Thirty cavity preparations (27 mm3) were prepared, and the thermal change (ΔT) was determined from a thermocouple inserted in the pulp chamber. The surface roughness of the dentin substrate was determined after veneer preparations using scanning white-light interferometry and scanning electron microscope imaging. The cleanability of TI and RI was also determined by comparing the efficacy of 3 conventional disinfection protocols after contaminating the instrument with Gram-positive or Gram-negative oral pathogens. The mean and standard deviation values for thermal change, surface roughness, and colony forming units were calculated at a 95% confidence level, and 1-way ANOVA was used to determine statistical significance (α=.05).
Results:
The NI instrument had the lowest mean ΔT (1.47 °C). The TI (1.77 °C) and RI (1.85 °C) groups showed statistically similar means (P>.05). The TI presented the lowest surface roughness (1.68 μm), followed by the RI (1.87 μm) (P<.001). The NI resulted in the highest surface roughness (2.17 μm) (P<.001). The disinfection protocols used were more effective on the TI group than on the RI group regardless of organisms and time exposed to the cleaning solution (P<.001).
Conclusions:
The novel diamond instrument demonstrated similar cutting efficiency and effectiveness when compared with conventional diamond instruments. However, the novel instrument produced smoother tooth preparations and was easier to clean than the conventional diamond rotary instruments.
