Micro-computed tomographic assessment of the shaping ability of the One Curve, One Shape, and ProTaper Next nickel-titanium rotary systems

A Comparative Evaluation of the Efficiencies of Different Rotary File Systems in Terms of Remaining Dentin Thickness Using Cone Beam Computed Tomography: An In Vitro Study

AIM

The aim of this study was to evaluate and compare the dentin thickness of the mesio-buccal canal of the lower first molar after canal preparation with three different rotary file systems using cone beam computed tomography (CBCT).

METHODOLOGY

TruNatomy (Dentsply Sirona, USA), 2Shape (Micro-Mega, France), and One Curve (Micro-Mega, France) were the three different rotary files that were employed. A total of 45 excised human permanent first mandibular molars were divided into Groups A (TruNatomy), B (2Shape), and C (One Curve) at random. To measure the residual dentin thickness at 3 mm, 5 mm, and 7 mm from the radiographic apex, the mesial root of the tooth was removed from the tooth, and a mesio-buccal canal was taken. Samples were mounted in clear acrylic resin and were subjected to a pre-instrumentation CBCT scan. The mesio-buccal canal was cleaned and shaped while maintaining the final mesio-buccal canal preparation of Group A - 26/0.04, Group B - 25/0.04, and Group C - 25/0.04. The samples were extensively irrigated with 3% sodium hypochlorite and 17% EDTA, and a post-instrumentation scan was performed on them. Statistics were used to determine the values from CBCT scans that were recorded for pre- and post-instrumentations.

RESULTS

The results showed that Group A had the greatest drop in dentin thickness, followed by Group B and Group C. The change in dentin thickness was greatest at 3 mm and 7 mm.

CONCLUSION

In contrast to TruNatomy and 2Shape rotary file systems, One Curve has the advantage of maintaining a tooth's thickness at 3 and 7 millimeters from the radiological apex. Since the TruNatomy file system removes more dentin than the other two combined, it should be used cautiously. Choosing the right instrument is crucial for cleaning and shaping during root canal preparation.

Accumulated Hard Tissue Debris and Root Canal Shaping Profiles Following Instrumentation with Gentlefile, One Curve, and Reciproc Blue

INTRODUCTION

This laboratory study aimed to evaluate the accumulated hard tissue debris (AHTD) and shaping performance following root canal instrumentation with a novel stainless steel rotary system (Gentlefile; MedicNRG, Kibbutz Afikim, Israel) compared with two single-file nickel-titanium instruments of different kinematics through micro-computed tomography (micro-CT) analysis.

METHODS

Thirty isthmus-containing mesial roots of human mandibular molars with a curvature of 15°-35° were scanned with micro-CT at an isotropic resolution of 12 μm and randomly assigned to three groups (n = 10) according to the instruments used for canal preparation: Gentlefile (GF; #23/.04), One Curve (OC; #25/.06; Micro-Mega, Besancon, France), and Reciproc Blue R25 (RB; #25/.08; VDW, Munich, Germany). The AHTD, unprepared canal surface area, volume changes, surface area changes, and transportation were evaluated by comparing preoperative and postoperative micro-CT images. In addition, the time required for canal preparation was recorded. Data were statistically analyzed using the one-way analysis of variance (ANOVA) test or the Kruskal-Wallis test at a significance level of 5%.

RESULTS

No significant differences were observed in the percentage of AHTD or in the unprepared canal surface area between the three groups (P > .05). The RB group demonstrated a significantly greater percentage increase in volume and surface area than the GF group (P < .05). The GF and OC groups showed significantly less transportation at 3 mm from the apex than the RB group (P < .001). The OC group required significantly less time for instrumentation than the RB and GF groups (P < .05).

CONCLUSIONS

Instrumentation with GF (#23/.04), OC, and RB yielded similar levels of AHTD and unprepared surface area in isthmus-containing curved canals. GF achieved this with less dentin removal and apical transportation, at the expense of a longer preparation time.

Comparative evaluation of canal transportation and canal centering ability in oval canals with newer nickel-titanium rotary single file systems - A cone-beam computed tomography study

Context

The purpose of this study was to evaluate and compare the centering ability and canal transportation of TruNatomy, OneCurve, and Jizai file systems to assess their performance in oval-shaped canals using cone-beam computed tomography imaging.

Materials and Methods

Forty-two fully formed single-rooted mandibular premolars were selected with a buccolingual canal size 2-2.5 times the mesiodistal size at 5 mm from the apex, with 0°-10° canal curvature with a 5-6 mm radius, at 5 mm from the apex. The teeth were divided into three groups (n = 14) and prepared with TruNatomy, OneCurve, and Jizai files based on the manufacturer's instructions. Cone-beam computed tomographic images were taken before and after instrumentation. The canal transportation and centering ability was calculated at 3, 6, and 9 mm from the apex in both mesiodistal and buccolingual directions.

Statistical Analysis

Intergroup comparison was done using Kolmogorov-Smirnov test. Intragroup comparison was done using Freidman test. A comparison of categorical variables was done using the Chi-square test.

Results

The results obtained did not present any statistically significant difference between the three groups, with TruNatomy and OneCurve showing relatively lesser canal transportation and better centering ratio when compared to the Jizai file system.

Conclusions

It can, therefore, be concluded that all three systems used in the study are capable of safely preparing root canals with minimal errors.

Comparative evaluation of canal transportation and centering ability of rotary and reciprocating file systems using cone-beam computed tomography: An in vitro study

Aim

The aim of the study was to evaluate the canal transportation and centering ability of rotary and reciprocating file systems using cone-beam computed tomography.

Materials and Methods

Mesiobuccal canals of sixty mandibular molars were selected for the study. Canals of length 19 mm, curvature of 10°-12°, and uncalcified with fully formed apex were selected. Canals were randomly divided into three groups of 20 teeth, and canal preparation with the WaveOne Gold, TruNatomy, and One Curve systems was performed according to the manufacturers' instructions. Cone-beam computed tomographic images were taken before and after instrumentation in the same position for comparative analysis.

Statistical Analysis Used

Apical transportation was calculated at the distances of 2, 3, and 4 mm from the apex. Tukey's post hoc test and unpaired "t"-tests were used to statistically analyze the data.

Results

WaveOne Gold caused less canal transportation and better-centering ability than TruNatomy and One Curve at all the three levels; there was a significant difference in canal transportation and centering ability among all the groups as well as all the three levels, i.e., 2, 3, and 4 mm from the apex.

Conclusion

WaveOne Gold (Reciprocating) reported less canal transportation and better-centering ability than rotary instruments TruNatomy and One Curve (Rotary) at all the three levels.

Micro-computed tomography in preventive and restorative dental research: A review

Purpose

The use of micro-computed tomography (micro-CT) scans in biomedical and dental research is growing rapidly. This study aimed to explore the scientific literature on approaches and applications of micro-CT in restorative dentistry.

Materials and Methods

An electronic search of publications from January 2009 to March 2021 was conducted using ScienceDirect, PubMed, and Google Scholar. The search included only English-language articles. Therefore, only studies that addressed recent advances and the potential uses of micro-CT in restorative and preventive dentistry were selected.

Results

Micro-CT is a tool that enables 3-dimensional imaging on a small scale with very high resolution. In this method, there is no need for sample preparation or slicing. Therefore, it is possible to examine the internal structure of tissue and the internal adaptation of materials to surfaces without destroying them. Due to these advantages, micro-CT has been recommended as a standard imaging tool in dental research for many applications such as tissue engineering, endodontics, restorative dentistry, and research on the mineral density of hard tissues and bone growth. However, the high costs of micro-CT, the time necessary for scanning and reconstruction, computer expertise requirements, and the enormous volume of information are drawbacks.

Conclusion

The potential of micro-CT as an emerging, accurate, non-destructive approach is clear, and the valuable research findings reported in the literature provide an impetus for researchers to perform future studies focusing on employing this method in dental research.