scholarly journals Effects of a Novel NiTi Thermomechanical Treatment on the Geometric Features of the Prepared Root Canal System

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5546
Author(s):  
Abdulwahed Alghamdi ◽  
Loai Alsofi ◽  
Khaled Balto

Objectives: This study aimed to compare the ex vivo performance of two rotary nickel–titanium (NiTi) systems with similar designs but manufactured from martensitic and austenitic alloys, the One Curve (OC) and One Shape (OS) rotary endodontic files, respectively. Methods: Forty separate mesial canals of 20 extracted mandibular molars were scanned using micro-computed tomography (CT), which were divided into 2 groups and instrumented with OC and OS, respectively. Post-instrumentation micro-CT scans were evaluated using validated computer algorithms to compare changes in canal thickness, surface area, structure model index (SMI) scores, volume of removed dentin, percentage of untreated canal surface, percentage of curvature straightening, and the amount of canal transportation. Results: Both files led to significant changes in the basic root canal geometry, with no preparation errors and no statistically significant differences. However, OC treatment resulted in significantly less curvature straightening (17.30%; 10.77%) (independent samples t test, p < 0.05) and less apical transportation (55.11 µm; 33.15 µm) (Mann–Whitney U, test p < 0.05) compared to OS treatment. Transportation values in the middle and coronal thirds were statistically similar (independent sample t-test, p > 0.05). OC treatment produced significantly less straightening and less apical transportation than OS.

2015 ◽  
Vol 61 (4) ◽  
pp. 304-310
Author(s):  
Monica Voiculeanu ◽  
◽  
Ioana Suciu ◽  
Bogdan Dimitriu ◽  
Mihaela Grigore ◽  
...  

Evaluation of post-operative root canal shape have been performed using simulated root canals in resin blocks and magnification analysis (stereomicroscope) have been used for the study. The technique selected was stepback with conventional hand stainless steel instruments. The aim of studies on post-operative root canal shape is to evaluate the conicity, taper and flow and maintenance of original canal shape and to record the degree and frequency of straightening, apical transportation, ledging, zipping, teardrops, elbows. Ideal preparation forms for the root canals can be possible without any preparation errors with circular incorporation of the original canal cross section – if the technique starts with adequately precurved negotiating files. Preparation errors (zips, canal transportation, apical perforations, elbows, teardrops, etc) can occur mostly when stainless steel hand instruments (K-file) are used for moderate to severe curved of root canals, especially K-file with cutting tips and not prebent. Ideal preparation shape without any preparation errors could be a final shape and adequate shape even for conventional hand files and step-back technique. For the first area of step back technique, even for the begining, we can usually use various prebent stainless steel hand instruments for pathfinding. In many cases, conventional hand instruments produces adequate shapes for the root canals. For this final shape, is important to use adequately precurved negotiating files. Conventional stainless stell are rigid enough that thay should be precurved to match the curvature of the canal during instrumentation. Conventional hand instruments has two basic design, Kerr-file and Kerr-reamer. Kerr-file could be used to enlarge the canal with a longitudinal filing action. Kerr-reamer may used in a same fashion, but is much more flexible instrument than K-file. Noncutting tip follow the canal better than instruments with active tips – clinically usefull element.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thomas Gerhard Wolf ◽  
Andrea Lisa Anderegg ◽  
David Haberthür ◽  
Oleksiy-Zakhar Khoma ◽  
Sven Schumann ◽  
...  

AbstractThe aim of this study was to investigate the root canal system morphology by means of a root canal configuration (RCC) classification described with a four-digit system, the physiological foramen geometry and accessory canal frequency and morphology, of 101 mandibular canines (MaCa) of a Swiss-German population by means of micro-computed tomography. Micro-CT examination of the MaCa was performed and the obtained images analyzed with a 3D imaging software. In single-rooted MaCas, the most frequently observed RCCs were 1-1-1/1 (74.5%) and 1-1-1/2 (14.3%). Seven other RCCs were less frequently observed with a frequency from 4.1 to 1.0%. One physiological foramen was observed in 80.6% of the MaCas, two in 16.3%, three in 1.0% and four in 2.0%. Accessory and connecting canals were apparent only in the middle and apical root thirds. Two-rooted MaCas occurred less frequently (n = 3). When one physiological foramen was present, the mean size of the narrow and wide diameters were 0.28 mm (± 0.07) and 0.40 mm (± 0.11), while the distance between physiological and anatomical foramen was 0.45 mm (± 0.17). MaCas are predominantly single-rooted teeth with a 1-1-1/1 or 1-1-1/2 RCC. Most MaCas had one physiological foramen with an oval shape.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alfredo Sierra-Cristancho ◽  
Luis González-Osuna ◽  
Daniela Poblete ◽  
Emilio A. Cafferata ◽  
Paola Carvajal ◽  
...  

AbstractThis study aimed to analyze the root anatomy and root canal system morphology of mandibular first premolars in a Chilean population. 186 teeth were scanned using micro-computed tomography and reconstructed three-dimensionally. The root canal system morphology was classified using both Vertucci’s and Ahmed’s criteria. The radicular grooves were categorized using the ASUDAS system, and the presence of Tomes’ anomalous root was associated with Ahmed’s score. A single root canal was identified in 65.05% of teeth, being configuration type I according to Vertucci’s criteria and code 1MP1 according to Ahmed’s criteria. Radicular grooves were observed in 39.25% of teeth. The ASUDAS scores for radicular grooves were 60.75%, 13.98%, 12.36%, 10.22%, 2.15%, and 0.54%, from grade 0 to grade 5, respectively. The presence of Tomes’ anomalous root was identified only in teeth with multiple root canals, and it was more frequently associated with code 1MP1–2 of Ahmed’s criteria. The root canal system morphology of mandibular first premolars showed a wide range of anatomical variations in the Chilean population. Teeth with multiple root canals had a higher incidence of radicular grooves, which were closely related to more complex internal anatomy. Only teeth with multiple root canals presented Tomes’ anomalous root.


2017 ◽  
Vol 22 (1) ◽  
pp. 31 ◽  
Author(s):  
Hugo Díez Ortega ◽  
Francisco Correa Toral ◽  
Leylin Delgado Hernández ◽  
Carolina Echavarría González ◽  
Fátima Serna Varona ◽  
...  

Endodontic disease has mainly a microbial origin. It is caused by biofilms capable of attaching and surviving in the root canal. Therefore, it is important to study the conditions in which those biofilms grow, develop and colonize the root canal system. However, few studies have used natural teeth as models, which would take into account the root canal anatomical complexity and simulate the clinical reality. In this study, we used human premolar root canals to standardize <em>in vitro</em> biofilm optimal formation conditions for microorganisms such as <em>Enterococcus faecalis</em>, <em>Staphylococcus aureus</em> and <em>Candida albicans</em>. 128 lower premolars underwent canal preparation using K-type files, and were treated with 5.25% sodium hypochlorite and EDTA. Samples were inoculated with microorganisms and incubated for 15, 30, 45, and 60 days under anaerobiosis (CO2 atmosphere) and aerobiosis. Microorganism presence was confirmed by Gram staining, cell culture, and electron microscopy. Exopolysaccharide matrix and microorganism aggregation were observed following 15 days of incubation. Bacterial growth towards the apical third of the root canal and biofilm maturation was detected after 30 days. CO2 atmosphere favored microbial growth the most. <em>In vitro</em> biofilm maturation was confirmed after 30 days of incubation under a CO2 atmosphere for both bacteria and yeast.


2018 ◽  
Vol 2 (4) ◽  
pp. 265-269
Author(s):  
Sharonit Sahar-Helft ◽  
Ayşe Sena Kabaş Sarp ◽  
Murat Gulsoy ◽  
Idan Redenski ◽  
Adam Stabholtz ◽  
...  

2013 ◽  
Vol 14 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Mina Zarei ◽  
Maryam Javidi ◽  
Mahdi Erfanian ◽  
Mahdi Lomee ◽  
Farzaneh Afkhami

ABSTRACT Aim Cleaning and shaping is one of the most important phases in root canal therapy. Various rotary NiTi systems minimize accidents and facilitate the shaping process. Todays NiTi files are used with air-driven and electric handpieces. This study compared the canal centering after instrumentation using the ProTaper system using Endo IT, electric torque-control motor, and NSK air-driven handpiece. Materials and methods This ex vivo randomized controlled trial study involved 26 mesial mandibular root canals with 10 to 35° curvature. The roots were randomly divided into 2 groups of 13 canals each. The roots were mounted in an endodontic cube with acrylic resin, sectioned horizontally at 2, 6 and 10 mm from the apex and then reassembled. The canals were instrumented according to the manufacturer's instructions using ProTaper rotary files and electric torque-control motors (group 1) or air-driven handpieces (group 2). Photographs of the cross-sections included shots before and after instrumentation, and image analysis was performed using Photoshop software. The centering ability and canal transportation was also evaluated. Repeated measurement and independent t-test provided statistical analysis of canal transportation. Results The comparison of the rate of transportation toward internal or external walls between the two groups was not statistically significant (p = 0.62). Comparison of the rate of transportation of sections within one group was not significant (p = 0.28). Conclusion Use of rotary NiTi file with either electric torquecontrol motor or air-driven handpiece had no effect on canal centering. Clinical significance NiTi rotary instruments can be used with air-driven motors without any considerable changes in root canal anatomy, however it needs the clinician to be expert. How to cite this article Zarei M, Javidi M, Erfanian M, Lomee M, Afkhami F. Comparison of Air-driven vs Electric Torque Control Motors on Canal Centering Ability by ProTaper NiTi Rotary Instruments. J Contemp Dent Pract 2013;14(1):71-75.


2016 ◽  
Vol 42 (4) ◽  
pp. 610-614 ◽  
Author(s):  
Thomas Gerhard Wolf ◽  
Frank Paqué ◽  
Maximilian Zeller ◽  
Brita Willershausen ◽  
Benjamín Briseño-Marroquín

2016 ◽  
Vol 13 (123) ◽  
pp. 20160589
Author(s):  
James Rafferty ◽  
Lance Farr ◽  
Tim James ◽  
David Chase ◽  
John Heinrich ◽  
...  

We present a novel, high-resolution magnetic resonance technique, fine structure analysis (FSA) for the quantification and analysis of amorphous and quasi-amorphous biological structures. The one-dimensional technique is introduced mathematically and then applied to one simulated phantom, two physical phantoms and a set of ex vivo biological samples, scanned with interpoint spacings of 0.0038–0.195 mm and cross-sectional sizes of 3 × 3 or 5 × 5 mm. The simulated phantom and one of the physical phantoms consists of randomly arranged beads of known size in two and three dimensions, respectively. The second physical phantom was constructed by etching lines on Perspex. The ex vivo samples are human bone specimens. We show that for all three phantoms, the FSA technique is able to elucidate the average spacing of the structures present within each sample using structural spectroscopy, the smallest of which was 180 µm in size. We further show that in samples of trabecular bone, FSA is able to produce comparable results to micro-computed tomography, the current gold standard for measuring bone microstructure, but without the need for ionizing radiation. Many biological structures are too small to be captured by conventional, clinically deployed medical imaging techniques. FSA has the potential for use in the analysis of pathologies where such small-scale repeating structures are disrupted or their size, and spacing is otherwise altered.


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