scholarly journals Micro-computed tomographic evaluation of the effect of the final apical size prepared by rotary nickel-titanium files on the removal efficacy of hard-tissue debris

2018 ◽  
Vol 46 (6) ◽  
pp. 2219-2229 ◽  
Author(s):  
Ke Xu ◽  
Juan Wang ◽  
Ke Wang ◽  
Nan Gen ◽  
Jin Li

Objective This study was performed to compare the removal efficacy of hard-tissue debris in mandibular first molars prepared to various apical sizes. Methods The mesial root canals of 40 extracted mandibular first molars were prepared by rotary nickel-titanium files to an apical size of #25/0.04 (Group #2504), #30/0.04 (Group #3004), #35/0.04 (Group #3504), and #40/0.04 (Group #4004). Irrigation was performed with 5.25% NaOCl and 17% EDTA. Micro-computed tomography was used to scan the samples before and after root canal preparation. Remnant hard-tissue debris was identified, quantified, and visualized three-dimensionally using shape recognition and image superimposition analysis, and the debris was mapped to its location. Results After preparation, 11.67%±2.99% of the root canals contained hard-tissue debris in Group #2504, 8.00%±2.71% in Group #3004, 7.17%±2.88% in Group #3504, and 4.51%±1.61% in Group #4004. The amount of accumulated hard-tissue debris was significantly less in Group #4004 than in the other groups. However, there were no significant differences between Groups #3004 and #3504. Conclusions An increased final apical size resulted in significantly lower debris accumulation. However, no root canal in any group was completely free from hard-tissue debris, and debris was mostly found in the isthmus of the mesial root canals.

2018 ◽  
Vol 47 (1) ◽  
pp. 325-334 ◽  
Author(s):  
Zhuwei Huang ◽  
Jingjing Quan ◽  
Jia Liu ◽  
Wen Zhang ◽  
Xiaolei Zhang ◽  
...  

Objective To evaluate the shaping ability of three thermally-treated rotary nickel-titanium (NiTi) systems including ProTaper Next (PTN), HyFlex™ CM (HFCM) and HyFlex™ EDM (HFEDM) during root canal preparation in simulated root canals. Methods A total of 45 simulated root canals were divided into three groups ( n = 15) and prepared with PTN, HFCM or HFEDM files up to size 25. Microcomputed tomography (microCT) was used to scan the specimens before and after instrumentation. Volume and diameter changes, transportations and centring ratios at 11 levels of the simulated root canals were measured and compared. Results HFEDM caused significantly greater volume increases than HFCM and PTN in the entire root canal and in the apical and middle thirds. HFCM removed the least amount of resin in the coronal third compared with HFEDM and PTN. Overall, HFCM caused significantly less transportation in the apical 2 mm and was better centred than PTN in the apical 3 mm. Conclusion Under the conditions of this study, all systems prepared curved canals without significant shaping errors and instrument fracture. PTN and HFCM cut less resin than HFEDM. HFCM stayed centred apically and cut the least material coronally.


2018 ◽  
Vol 12 (1) ◽  
pp. 32-45 ◽  
Author(s):  
Iussif Mamede-Neto ◽  
Álvaro Henrique Borges ◽  
Ana Helena Gonçalves Alencar ◽  
Marco Antonio Hungaro Duarte ◽  
Manoel Damião Sousa Neto ◽  
...  

Objective: To evaluate transportation (T) and centering ability (CA) of root canal preparations using continuous or reciprocating nickel-titanium endodontic files. Materials and Methods: Ninety-six mesiobuccal root canals of mandibular first and second molars were randomly divided into 6 groups (n=16) according to the rotary file used: 1. ProTaper Next; 2. ProTaper Gold; 3. Mtwo; 4. BioRaCe; 5. WaveOne Gold; 6. Reciproc. Root canals were prepared according to manufacturer’s instructions. Cone beam computed tomography scans were obtained before and after root canal preparation. Measurements were made at six different reference points: 2, 3 and 4 mm from the apex and 2, 3 and 4 mm below furcation in different directions. Results: The greatest Mesiodistal (MD) Transportation (T) was found for Reciproc files (p<0.05), and the greatest buccolingual (BL) T, for Reciproc, ProTaper Gold and ProTaper Next files (p<0.05). The greatest Mesiodistal (MD) Centering Ability (CA) was found for BioRaCe files (p<0.05), and the greatest Buccolingual (BL) CA, for BioRaCe and Mtwo files (p<0.05). Conclusion: All systems produced root canal transportation. No file system achieved perfect CA of root preparation. Reciproc files had the greatest MD T and BL T. BioRaCe files had the greatest MD CA, whereas BL CA was similar for BioRaCe and Mtwo files.


2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Dongqing Wu ◽  
Jian Gao ◽  
Xiaoli Hu ◽  
Zhengtao Xiao ◽  
Zhuwei Huang ◽  
...  

In recent years, we have seen more and more interest in the field of medical images and shape comparison motivated by the latest advances in microcomputed tomography (μCT) acquisition, modelling, and visualization technologies. Usually, biologists need to evaluate the effect of different root canal preparation systems. Current root canal preparation evaluation methods are based on the volume difference, area difference, and transportation of two root canals before and after treatment. The purpose of root canal preparation is to minimize the volume difference and ensure the complete removal of the smear layer. Previous methods can reflect some general geometric differences, but they are not enough to evaluate the quality of root canal shape. To solve this problem, we proposed a novel root canal evaluation method based on spectrum and eigenfunctions of Steklov operators, which can be served as a better alternative to current methods in root canal preparation evaluation. Firstly, the ideal root canal model was simulated according to the root canal model before and after preparation. Secondly, the Steklov spectrum of the two models was calculated. Thirdly, based on the spectrum and the histogram of the Gaussian curvature on the surface, the weight of each eigenvalue was computed. Therefore, the Steklov spectrum distance (SSD), which measures shape difference between the root canals, was defined. Finally, the calculation method that quantifies the root canal preparation effect of root canals was obtained. Through experiments, our method manifested high robustness and accuracy compared with existing state-of-the-art approaches. It also demonstrates the significance of our algorithm’s advantages on a variety of challenging root canals through result comparison with counterpart methods.


2018 ◽  
Vol 21 (1) ◽  
pp. 104
Author(s):  
Tatiane Pires Nogueira ◽  
Ellen Roberta Lima Bessa ◽  
Eduardo Da Costa Nunes ◽  
André Augusto Franco Marques ◽  
Lucas Da Fonseca Roberti Garcia ◽  
...  

<p><strong>Objective:</strong> To evaluate the effect of glide path creation on transportation promoted by NiTi and M-Wire instruments. <strong>Material and Methods: </strong>Sixty polyester resin blocks containing a simulated root canal were distributed into four groups (n=15), according to the protocols/systems used for root canal preparation: GPR group - glide path + Revo-S system; R group - no glide path + Revo-S system; GPPN group - glide path + ProTaper Next system and PN group - no glide path + ProTaper Next system. Root canals were photographed before and after preparation, and the images were superimposed to evaluate the transportation at the apical, middle and coronal thirds. The time spent to perform preparation was also measured (seconds). Data were submitted to the non-parametric Kruskal-Wallis test (p&lt;0.05) for statistical analysis. <strong>Results:</strong> In the apical third, there was no significant difference among groups (p&gt;0.05). GPR and R groups were similar in the middle third (p&gt;0.05). However, the transportation value in GPR group was statistically higher in comparison with GPPN and PN groups (p&lt;0.05). In the coronal third, GPR and R groups were similar (p&gt;0.05). Only R group presented significant difference in comparison with GPPN and PN groups (p&lt;0.05). There was no difference among groups about time spent to perform preparation (p&gt;0.05). <strong>Conclusion:</strong> None of the systems were capable of maintaining the original trajectory of the simulated root canal, and the glide path had no effect on the transportation promoted by instruments.</p><p><strong>Keywords</strong></p><p>Dental instruments; Endodontics; Root canal preparation.</p>


2021 ◽  
Vol 38 (3) ◽  
pp. 291-298
Author(s):  
Nenad Stošić ◽  
Jelena Popović ◽  
Marija Anđelković-Apostolović ◽  
Aleksandar Mitić ◽  
Marija Nikolić ◽  
...  

One of the primary goals in endodontics is efficient cleaning and shaping of the root canal while maintaining its original configuration. Numerous studies highlight the advantage of using nickel-titanium instruments and the most important is their high flexibility and the ability to penetrate the curved canals. The aim of this study was to analyze the ultrastructure of the surface of nickel-titanium endodontic files before and after use. Eighty-four instruments were included in this study. The instruments were used one, three and six times for root canal preparation on extracted upper premolars. The analysis was performed based on the number of uses and the size of the instruments. Changes on flat surfaces in the grooves of the instruments, defects of the cutting edges and fractures were evaluated. The surface ultrastructure was analyzed on a scanning electron microscope (SEM). SEM analysis showed irregularities on the surfaces of the new instruments. Surface defects and damage of the cutting edges were present after the first use. After three uses, the damage was more evident in instruments of all sizes. After six uses, all instruments showed damage of the cutting edges, and a significant number of fractures were observed. Irregularities on the working parts are already noticed on the new endodontic instruments and originate from the production process. The first signs of damage appear after the first use. In order to prevent errors in clinical work during root canal preparation, it is recommended that the number of instruments uses should be limited.


2021 ◽  
Vol 10 (21) ◽  
pp. 4977
Author(s):  
Saulius Drukteinis ◽  
Goda Bilvinaite ◽  
Hagay Shemesh ◽  
Paulius Tusas ◽  
Vytaute Peciuliene

The present study evaluated the effect of ultrasonic agitation on the porosity distribution of BioRoot RCS/single gutta-percha cone (BR/SC) and MTA Flow (MF) root canals fillings used as apical plugs in moderately curved and apically perforated roots. Eighty mesial root canals of mandibular first molars were enlarged up to ProTaper NEXT X5 rotary instrument 2 mm beyond the apical foramen, simulating apical perforations. Specimens were randomly divided into four experimental groups (20 canals per group) according to the material and technique used for root canal obturation: BR/SC, BR/SC with ultrasonic agitation (BR/SC-UA), MF and MF with ultrasonic agitation (MF-UA). The ultrasonic tip was passively inserted into the root canal after the injection of flowable cement and activated for 10 s. The specimens were scanned before and after obturation with a high-resolution micro-computed tomography scanner, and the porosity of the apical plugs was assessed. The differences between groups were analyzed using the Kruskal-Wallis and Mann-Whitney tests, with the significance level set at 5%. None of the obturation materials and techniques used in this study was able to provide a pore-free root canal filling in the apical 5 mm. Considerably higher percentages of open and closed pores were observed in the MF and MF-UA groups, with the highest porosity being in the MF-UA group (p < 0.05). No significant differences were observed between the BR/SC and BR/SC-UA groups, where the quantity of open and closed pores remained similar (p > 0.05).


2016 ◽  
Vol 27 (6) ◽  
pp. 664-669 ◽  
Author(s):  
Gustavo De-Deus ◽  
Felipe Gonçalves Belladonna ◽  
Juliana Roter Marins ◽  
Emmanuel João Nogueira Leal Silva ◽  
Aline de Almeida Neves ◽  
...  

Abstract This study aimed to evaluate the cause-effect relationship between canal preparation with ProTaper Universal (PTU) system and dentinal defects formation using micro-computed tomography (micro-CT) analysis. Forty mesial canals of mandibular molars with a type II Vertucci's canal configuration were scanned at an isotropic resolution of 14.16 µm. The sample was assigned to an experimental (n = 30) and a control (n = 10) groups, and the mesial canals were prepared with PTU system up to F2 instrument. The specimens from the experimental group were scanned and the cross-section images of the mesial roots, before and after preparation, were screened to identify the presence of dentinal defects. In the control group, the specimens were sectioned perpendicularly to the long axis of the root into 1-mm-thick slices (n = 80) and examined under optical microscope. Once a dentinal defect was detected, the slice was scanned through micro-CT. In the experimental group, dentinal micro-cracks were observed in 4,828 slices (24.04%). In all cross-section images, dentinal defects identified in the postoperative images were already present in the corresponding preoperative image. In the control group, 13 out of 80 slices (16.25%) had at least one dentinal defect visualized under stereomicroscopy, which was identified after a further micro-CT scanning. Micro-CT showed reliability as similar as optical microscopy in detecting dentinal defects, adding the possibility of tracking the dentinal tissue, before and after canal preparation, and providing a clear visualization of micro-cracks. Root canal preparation with PTU system did not induce the formation of new dentinal defects.


2017 ◽  
Vol 43 (7) ◽  
pp. 1143-1147 ◽  
Author(s):  
Bruna Paloma de Oliveira ◽  
Andréa Cruz Câmara ◽  
Daniel Amancio Duarte ◽  
Richard John Heck ◽  
Antonio Celso Dantas Antonino ◽  
...  

Author(s):  
Ali Keleş ◽  
Cangül Keskin

Objective: Isthmuses are narrow communications between root canals, and form as the result of the merging of the two root canals widening in a buccolingual direction. This widening causes the high ovality of isthmuses. The shaping and cleaning of all root canal systems are regarded as one of the major difficulties in long-oval shaped root canals. This study aims to make quantitative analysis of Vertucci type II root canal systems following preparation with Self- Adjusting file (SAF), Reciproc or Revo-S. Methods: Major diameter and roundness values were measured at the level 1.2 mm from apical foramen before and after preparation. A ‘post-preparation node’ point was described when the minimum minor diameter value was smaller than major diameter of apical 1.2 mm. Data were analysed using one-way ANOVA, Tukey and Chi-square tests. Results: Preparation resulted in a significant increase in the major diameter values regardless of the instrumentation (p = 0.000). Preparation with Reciproc led to the significant increase in roundness values (p = 0.000), whereas no significant difference was detected in specimens prepared with SAF (p = 0.21) and Revo-S (p = 0.15). Conclusion: Root canal preparation with SAF, Reciproc and Revo-S led to a significant increase in the major diameter of apical 1.2 mm and resulted in high frequencies of the post-preparation node.


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