Basic ResearchRoot Canal Shaping Effect of Instruments with Offset Mass of Rotation in the Mandibular First Molar: A Micro–computed Tomographic Study
Section snippets
Materials and Methods
The study was approved by the Ethics Committee of the University of Dental Medicine, Mandalay, Myanmar (#20150202). Thirty-six extracted mandibular first molars with a slight apical binding for a #10 K-file in the 2 independent mesial canals (15°–30° curvature) and a #15 K-file in 1 single oval distal canal (5°–20° curvature) were selected (8). The specimens were scanned before and after root canal instrumentation with the same setting using a SkyScan 1272 scanner (Bruker micro-CT, Kontich,
Results
At 1 mm from the apical foramen, the PTN and RS groups showed significantly less transportation and better centering ability than the PTU group (P < .05). However, no significant differences were noted at other levels from the apical foramen in the mesial canals and at all levels from the apical foramen in the distal canals among the instrument groups (P > .05). Before root canal instrumentation, there was no significant difference among the 3 groups regarding canal area, volume, and SMI value (
Discussion
The present study evaluated the shaping effect on root canal geometry of the mandibular first molar of the 2 file systems with offset masses of rotation compared with 1 conventional file system with a centered mass of rotation using micro-CT analysis. In the present study, both systems with offset mass of rotation showed significantly less transportation and better centering ability than the conventional file system with a centered mass of rotation.
Generally, the shaping effect of NiTi rotary
Acknowledgments
The authors deny any conflicts of interest related to this study.
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Micro–computed Evaluation of Canal Transportation and Centering Ability of 5 Rotary and Reciprocating Systems with Different Metallurgical Properties and Surface Treatments in Curved Root Canals
2021, Journal of EndodonticsCitation Excerpt :The overall results of this study showed that rotary techniques (ie, PTN, TRN, and XPS) caused similar transportation and centering ability in curved canals at all canal levels (3, 5, and 7 mm). The behavior of the PTN instruments in curved canals is well-known from previous studies, which reported their minimal canal transportation that is comparable with other rotary techniques5,15–17. Yuan and Yang18 observed that PTN caused lesser canal transportation compared with the reciprocating system (WaveOne).
Cleaning and Shaping Ability of Gentlefile, HyFlex EDM, and ProTaper Next Instruments: A Combined Micro–computed Tomographic and Scanning Electron Microscopic Study
2020, Journal of EndodonticsCitation Excerpt :In this study, the median percentages of the untouched areas ranged from 6.9%–10.6% and 8.7%–10.2% for the apical and middle regions, respectively (Fig. 1J). This result agrees with previous micro-CT–based studies reporting that portions of canal areas remain untouched after instrumentation of oval-shaped canals4,10–14. In particular, 1 study using mandibular premolars has shown that 17.6% and 34.6% of canal areas remain untouched in the apical 4 mm and 10 mm, respectively, after NiTi rotary instrumentation10.
Cone-Beam Computed Tomographic Analysis of Shaping Ability of XP-endo Shaper and ProTaper Next in Large Root Canals
2020, Journal of EndodonticsCitation Excerpt :However, the mean increase in the prepared dentin area of XPS was more than 100% even in the apical third of the experimental group with the largest canals, which was also statistically significant (P < .05). It was known that rotary instruments with the same tip size and tapers would cause a similar amount of dentin removal, whereas the amount of dentin removed would be higher with larger taper with the same tip size16–18. In the present study, XPS and PTN X3 files had the same tip size, but variable tapers were used.
Comparative study of two novel nickel-titanium instruments for root canal preparation in curved canals on shaping ability and microcrack formation
2023, Shanghai Kou Qiang Yi Xue / Shanghai Journal of Stomatology