Publications by authors named "Nishijo Miki"
Background/purpose: The glide path instruments are the introductory instruments into the canals; thus, they should be durable enough to withstand torsional stress/screw-in force. This study aimed to investigate the torque and screw-in force of TruNatomy Glider (TN), ProGLIDER (PG), Hyflex EDM (EDM) and Dent Craft RE (RE) glide path instruments in single- and double-curved canals.
Materials And Methods: Each instrument brand was divided into two groups (n = 7 each) according to the canal configuration.
Background: To evaluate the effect of pecking motions with faster upward speed on the dynamic cyclic fatigue resistance of nickel-titanium rotary instruments with different metallurgy.
Methods: Forty each of ProTaper Universal F3 (PTU) and ProTaper Gold F3 (PTG) instruments (size #30/.09) were equally divided into four groups.
Article Synopsis
- The study examined the mechanical properties of modern heat-treated nickel-titanium rotary instruments used in dentistry, comparing ProTaper Next (PTN), HyFlex EDM (EDM), JIZAI (JZ), and a non-heat-treated instrument (nJZ).
- EDM and JZ showed better performance with lower bending loads and greater resistance to cyclic fatigue than nJZ and PTN.
- JZ outperformed other instruments in maintaining canal curvature and generated less torque and upward force compared to PTN and EDM, showing comparable flexibility to EDM.
Introduction: This study aimed to analyze torque/force generation and transportation in double-curved canals instrumented with 3 types of glide path files using optimum glide path (OGP) motion in comparison with continuous rotation.
Methods: Sixty simulated double-curved canals were prepared with #10/0.05 or #15/0.
Introduction: This study compared the static and dynamic cyclic fatigue resistance of contemporary nickel-titanium instruments with different kinematic, metallurgic, and design features to establish whether the fatigue-reducing effect of the pecking motion differs among different nickel-titanium instruments.
Methods: ProTaper Gold (PTG), Hyflex EDM (EDM), Reciproc Blue (RPB), and WaveOne Gold (WOG) files were divided into 2 groups of 10 for the static and dynamic cyclic fatigue resistance tests. A stainless steel artificial canal with 1.
Introduction: This ex vivo study aimed to evaluate the cleaning and shaping ability of a unique stainless steel rotary system (Gentlefile; MedicNRG, Kibbutz Afikim, Israel) compared with 2 nickel-titanium rotary instruments.
Methods: Thirty human mandibular premolars with a 15° to 25° curvature were equally distributed into 3 groups for final instrumentation with Gentlefile Red (#23/0.04), HyFlex EDM OneFile (#25/0.
Article Synopsis
- OTR motion is a torque-sensitive technique where the motor alternates between 90° counterclockwise and 180° clockwise turns to manage torque levels during nickel-titanium rotary instrumentation.
- The study involved two groups (OTR vs. continuous rotation) and two preparation techniques (crown-down and single-length) applied to simulated canal models to measure torque and force during instrumentation.
- Results indicated that OTR motion significantly reduced maximum torque and upward force compared to continuous rotation, particularly during the crown-down phase and apical preparation, suggesting benefits for efficiency in dental procedures.
Article Synopsis
- The study evaluated the impact of thermal treatment on the performance of nickel-titanium rotary instruments used in dental procedures.
- Reciproc Blue, which underwent post-machining thermal treatment, demonstrated less deviation in canal centering and lower torque/force generation compared to Reciproc.
- Results suggest that the thermal treatment improves the precision and efficiency of these dental instruments during root canal treatments.
Article Synopsis
- This study compared the effectiveness of NiTi rotary glide path preparation using HyFlex EDM Glide Path Files with manual stainless steel K-file instrumentation.
- Findings showed that rotary instruments (both OGP and CR) produced lower screw-in force and higher torque and canal volume changes compared to manual methods.
- The CR method was the most effective, achieving the highest torque and canal volume alterations, while OGP had smaller torque and volume changes than CR.
Article Synopsis
- - The study evaluated the cyclic fatigue resistance and bending properties of WaveOne Gold (WOG) Primary versus WaveOne (WO) Primary and Reciproc (RE) R25, finding that WOG Primary was more resistant to fracture.
- - In bending tests, WOG Primary exhibited lower load values at specific deflection points compared to WO Primary, indicating improved flexibility.
- - Torque/force measurements showed that WOG Primary produced lower maximum torque compared to RE R25, suggesting it requires less force to operate effectively.
Article Synopsis
- This study examined how different speeds of motion impact the performance of ProTaper Next rotary instruments in root canal treatment.
- Researchers tested three speed settings (low, medium, high) on simulated canals and measured the centering ability and force generated by the instruments.
- Results showed that higher speeds improved centering ability but also increased the forces and torque produced, with some instruments experiencing fractures at these speeds.
Objective: This study aimed to evaluate the ability of swept-source optical coherence tomography (OCT) to detect internal anatomy of maxillary premolars in comparison with dental operating microscope (DOM) and cone beam computed tomography (CBCT).
Background Data: The ability of OCT to observe the pulp horn during cavity preparation and assess the remaining dentin thickness (RDT) has been demonstrated, whereas validation of OCT in comparison with other imaging techniques seems required.
Methods: Ten extracted human maxillary premolars were sectioned perpendicular to the tooth axis from the occlusal surface at approximately 2 mm increments.
Article Synopsis
- The study investigated the mechanical properties of nickel-titanium rotary glide path files, focusing on flexibility and fracture resistance.
- EDM files exhibited higher torque at fracture and greater cyclic fatigue resistance than both GPF and RaCe control files.
- GPF demonstrated lower bending loads but longer time to cyclic fracture compared to RaCe, while reciprocation improved fatigue resistance for both EDM and GPF.
Article Synopsis
- The study compared two types of reciprocal movement (torque-sensitive and time-dependent) with continuous rotation during nickel-titanium rotary root canal work to analyze their effects on torque and apical force.
- A custom device was used for root canal instrumentation, with three groups tested: torque-sensitive reciprocal, time-dependent reciprocal, and continuous rotation.
- Results showed that the reciprocal methods produced lower maximum torque and apical force compared to continuous rotation, suggesting these methods could minimize stress during the procedure.