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1.
Quintessence Int ; 0(0): 0, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38726763

RESUMEN

OBJECTIVE: An altered sensation during endodontic treatment can occur due to the extrusion of endodontic materials. This study aims to discuss intentional replantation to address paresthesia resulting from an endodontic file penetrating the inferior alveolar nerve canal (IANC) and provide a protocol for managing nerve injuries in such incidents. CASE PRESENTATION: A 12-year-old girl developed paresthesia when an endodontic file separated and was inadvertently pushed through the apical foramen into IANC during root canal treatment of the mandibular left first molar. A CBCT scan revealed the file penetrating the canal towards the inferior border of the mandible. After considering the treatment options, intentional replantation was deemed suitable. The tooth was a-traumatically extracted and preserved in sterile saline. The surgeon then carefully cleaned and irrigated the socket. The radiographic assessment confirmed successful file removal from the socket. The Root ends were resected, and retrograde preparation and obturation were conducted using ultrasonic tips and MTA. The tooth was then replanted into the socket. Successful replantation was confirmed by tooth stability and an audible click. The patient was prescribed antibiotics and steroids. Subsequently, after completing the endodontic treatment. a stainless-steel crown was cemented. The successful intentional replantation procedure resulted in rapid improvement in the patient's condition. The normal sensation had been restored, indicating nerve recovery. At the 15-month follow-up, Periapical bone healing and the eruption of the adjacent second molar were observed, affirming the treatment protocol's overall success. CONCLUSION: Prompt intervention and immediate intentional replantation facilitated direct inspection of the separated file within the socket. Collaboration between an oral maxillofacial surgeon and an endodontist ensures expedited and targeted treatment, leading to favorable outcomes.

2.
Saudi Dent J ; 36(4): 656-660, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38690374

RESUMEN

Introduction: Comparative evaluation of the newly introduced; RACE EVO file system to the currently well-performing file systems like HyFlex EDM OneFile, Vortex Blue, ProTaper Gold (PTG) with regards to the cyclic fatigue resistance. Materials: &Methods.The endodontic rotary files under evaluation were segregated into four groups as follows:; RACE EVO, PTG, Vortex Blue, and HyFlex EDM OneFile. A detailed physical analysis of the cyclic fatigue resistance was performed in 15 files of each type (n = 60). Under the test conditions of 37 °C the test samples were subjected to continuous motion at the manufacturer recommended speed within an artificial curved canal until it fractured. For all the test samples, with the recording of time of fracture, calculation was done for number of cycles to fracture (NCF). In addition, the length of the fractured segment was determined. The fractured surface was further evaluated with scanning electron microscopic (SEM) images. Results: Highest significance for NCF was seen in HyFlex EDM OneFile followed by the Vortex Blue, PTG, and; RACE EVO (p < 0.05) by analyzing the data statistically. Significant differences among the lengths of the fractured segments were evident among tested files, ranging between 4.73 and 6.3 mm (p < 0.05) with HyFlex EDM OneFile uniquely differentiating from the others showing the fracture at 6.3 mm. The common features of cyclic fatigue failure was further substantiated by SEM images. Conclusions: Compared to the HyFlex EDM OneFile, Vortex Blue, and PTG files; RACE EVO demonstrated significantly lower resistance to cyclic fatigue.

3.
J Pharm Bioallied Sci ; 16(Suppl 1): S380-S382, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38595630

RESUMEN

Objective: Using cone beam computed tomography (CBCT), this study compared three rotary file systems-XP Endoshaper, Hyflex CM, and K3 XF-for centering, canal transportation, and root canal area growth. Materials and Methods: The rotating file system randomly separated 60 removed human mandibular molars into three groups (n = 20). Manufacturer-recommended root canal instrumentation was done. Specialized software examined pre- and post-instrumentation CBCT scans. Centering ability was measured by canal transportation and root canal area expansion at different levels from the apex. Results: The Hyflex CM file system had the best centering and the least canal transit at all levels (P < 0.05). XP Endoshaper increased the root canal area the most (P < 0.05). The K3 XF file system had average centering and canal transfer results. Conclusion: The Hyflex CM system centered well, whereas the XP Endoshaper system increased the root canal area the most. The clinical context and therapeutic goals should determine the rotating file system.

4.
Cureus ; 16(2): e54427, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38510902

RESUMEN

Objectives This study aimed to assess the awareness, implementation, and compliance with the infection control policy recommended by the Saudi Ministry of Health (MOH) for the use and reprocessing of endodontic files and to examine the association between compliance and gender, experience, clinical ranks, and workplace sector. Methods This was a cross-sectional study conducted using a validated self-administered electronic questionnaire created and distributed to dentists who perform endodontic treatment in Saudi Arabia. Data were collected between June and July 2023. Descriptive statistics were reported as counts and percentages. Comparisons among the demographic groups were done using the Kruskal-Wallis and Mann-Whitney tests. Results A total of 402 dentists completed the survey. The results showed that 76.1% (n=306) of respondents claimed that they were aware of the infection control policy recommended by the Saudi MOH for the use and reprocessing of endodontic files in dental clinics. Only 13.2% (n=53) of dentists used single-use endodontic files, and 36.6% (n=147) did not use an endodontic box in their dental clinics. The most commonly reported method of tracing the number of uses of endodontic files was to write the ID of the patient or the number of uses on the sterilization pouch as reported by 37.6% of participants (n=151). The average compliance score percentage was 63.5 ± 16.7. Most of the respondents showed moderate to high levels of compliance (51.7% (n=208) and 42.0% (n=169) of dentists, respectively). Dentists with less than 5 years of experience showed significantly less compliance than dentists with more than 10 years of experience (p = 0.005). Gender, clinical rank, and workplace sector were not significantly associated with the extent of adhering to the evaluated infection control policy. Conclusions Our findings indicate a relatively high level of compliance with the Saudi MOH policy of using and reprocessing endodontic files. However, critical measures such as the single-use of endodontic files, sterilizing new endodontic files, and using the sterilized endodontic box for each patient need improvement. Hence, this study recommends enhancing awareness through continuous education and training.

5.
Aust Endod J ; 50(1): 97-109, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37994546

RESUMEN

The purpose of the study is to evaluate the influence of the pecking motion (reciprocal axial motion) surgical technique on the durability behaviour of the Nickel-Titanium endodontic files using Finite Element Analysis (FEA). A commonly used endodontic file, ProTaper Universal F2, is selected for the study. Root canal treatment procedure is simulated on a test-bench (simulated root canal) proposed by G. Gambarini for cyclic fatigue loading of endodontic files with and without the pecking motion via FEA. The hysteresis energy density is used as evaluation criteria for low cycle fatigue life estimation of Shape Memory Alloy files. In an additional study, the root canal treatment procedure is also simulated for an FEA model of a molar tooth with significant root canal curvature to understand the influence of the realistic curvature of a root canal on the fatigue behaviour of endodontic files. For the simulated root canal, analysis accurately predicts the endodontic file's failure location, and fatigue life estimation based on the hysteresis energy density is shown to increase significantly with the introduction of the pecking motion, an observation confirmed by reported experimental results. Molar tooth simulations reveal greater file fatigue resistance than in simulated root canals, confirming the pecking motion's efficacy in enhancing file durability, even in real root canal conditions. Simulations indicate that the pecking motion technique increases the fatigue life of endodontic files for simulated as well as real root canals and the hysteresis energy is confirmed as an acceptable parameter to quantify fatigue life of Nickel-Titanium endodontic files.


Asunto(s)
Níquel , Preparación del Conducto Radicular , Preparación del Conducto Radicular/métodos , Titanio , Análisis de Elementos Finitos , Ensayo de Materiales , Diseño de Equipo , Cavidad Pulpar/cirugía , Aleaciones Dentales
6.
Restor Dent Endod ; 48(4): e38, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38053782

RESUMEN

Objectives: The aim of this study was to examine the use of hand or rotary files by pre-graduation (fourth- and fifth-year) and postgraduate students in endodontic treatments and to determine the incidence of file fracture and the management of cases with broken instruments. Materials and Methods: A total of 2,168 teeth undergoing primary endodontic treatment were included in this study. It was determined that 79 of these teeth resulted in broken tools. In the case of broken tools, the education level of the treating clinician, the tooth that was being treated, the canal and fracture level, the curvature of the tooth and the management of the broken instrument were recorded. Periapical radiographs of the patients were used to calculate curvature following the Schneider method. Results: There was no significant difference in the incidence of broken tools according to education level (p > 0.05). The incidence of file fracture in molar teeth (73.4%) was higher than in other teeth (p < 0.05). More files were broken in the mandibular molar MB canal (20.25%) and in the apical third of the canals (72.1%). The risk of instrument fracture was high in teeth with moderate (44.3%) and severe (38%) curvature canals. The management of apically broken (80%) files mostly involved lefting (p < 0.05). Conclusions: There was no statistically significant difference between fourth-year students, fifth-year students and postgraduate students in terms of instrument fracture.

7.
Cureus ; 15(11): e48768, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38098913

RESUMEN

Background and objective The main goal of root canal treatment is to eliminate microorganisms from the canal and to prevent re-infection. To achieve these goals, instrumentation must be combined with adequate irrigation and the placement of intracanal medicament. This study aims to compare the effect of different irrigation activation techniques, i.e., passive ultrasonic irrigation (PUI), EndoActivator (EA), and conventional needle irrigation on the penetration of calcium hydroxide (CH), an intracanal medicament into dentinal tubules. Methodology A total of 60 single-rooted extracted human teeth were selected, which were de-coronated to standardize the root length of 12 mm. An access cavity was prepared, and biomechanical preparation was done. The samples were randomly assigned to three experimental groups: Group I received conventional needle irrigation, Group II underwent EA irrigation, and Group III was subjected to PUI. All the samples were filled with CH paste mixed with Rhodamine B dye, and the orifice openings were sealed with Cavit. The samples were stored in an incubator for 24 hours and were subsequently sectioned horizontally at the coronal, middle, and apical thirds using a hard tissue microtome. These were observed under a confocal laser scanning microscope to evaluate the depth of medicament penetration. Statistical analysis was performed using IBM SPSS Statistics for Windows, Version 25.0 (IBM Corp., Armonk, NY). The Shapiro-Wilk test was employed to assess normality, while ANOVA and Tukey's post hoc analysis were utilized to determine significance. Results It was observed that the depth of penetration of CH into dentinal tubules was highest in Group III (PUI), followed by Group II (EA irrigation), with the least penetration observed in Group I (conventional needle irrigation). All the groups showed maximum penetration at the coronal third followed by the middle and apical third. Conclusions Passive ultrasonic irrigant activation resulted in more penetration of CH into the dentinal tubules followed by EA irrigant activation.

8.
Sensors (Basel) ; 23(9)2023 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-37177499

RESUMEN

Prognostic and health management technologies are increasingly important in many fields where reducing maintenance costs is critical. Non-destructive testing techniques and the Internet of Things (IoT) can help create accurate, two-sided digital models of specific monitored objects, enabling predictive analysis and avoiding risky situations. This study focuses on a particular application: monitoring an endodontic file during operation to develop a strategy to prevent breakage. To this end, the authors propose an innovative, non-invasive technique for early fault detection based on digital twins and infrared thermography measurements. They developed a digital twin of a NiTi alloy endodontic file that receives measurement data from the real world and generates the expected thermal map of the object under working conditions. By comparing this virtual image with the real one acquired by an IR camera, the authors were able to identify an anomalous trend and avoid breakage. The technique was calibrated and validated using both a professional IR camera and an innovative low-cost IR scanner previously developed by the authors. By using both devices, they could identify a critical condition at least 11 s before the file broke.

9.
Radiol Case Rep ; 17(12): 4928-4931, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36304075

RESUMEN

Ingestion and aspiration can be accidental or intentional events in both adults and children. Approximately 1500 people in the United States die from ingestion of foreign bodies annually. Patients with cognitive disabilities, neurological disorders, elderly age or incarcerated patients carry the highest risk of intentional and/or accidental ingestion of foreign objects. Although uncommon, ingestion of foreign objects during dental procedures can be potentially life-threatening and increased awareness is important. Sharp objects ingested from dental procedures can cause impaction, obstruction, hemorrhage, or perforation and may need endoscopic or surgical intervention. Herein we report a case of a 22-year-old male, who underwent routine dental cleaning and accidentally ingested an endodontic file, retrieved from the ascending colon endoscopically without complications.

10.
J Clin Med ; 11(9)2022 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-35566767

RESUMEN

In this article, the effects of cross-section and pitch on the mechanical response of NiTi endodontic files is studied by means of finite element analyses. The study was conducted over a set of eight endodontic rotary files, whose geometry was obtained from combinations of two cross-sections (square and triangular) and four pitches. Each file was subjected to bending and torsional analyses, simulating the testing conditions indicated in the ISO 3630 Standard, in order to assess their stiffness and mechanical strength. The results indicate that endodontic files with a square cross-section have double the stiffness of those with triangular cross-sections, both in terms of bending and torsion. For both loading modes, endodontic files with a triangular cross-section can undergo larger deformations before overload failure than those with a square cross-section: up to 20% more in bending and 40% in torsion. Moreover, under equivalent boundary conditions, endodontic files with triangular cross-sections present a higher fatigue life than those with square cross-sections: up to more than 300% higher for small pitches. The effect of pitch on the stiffness and strength of the file is smaller than that of the cross-section shape, but smaller pitches could be beneficial when using a triangular cross-section, as they increase the bending flexibility, fatigue life, and torsion stiffness. These results suggest a clinical recommendation for the use of files with a triangular-shaped cross-section and a small pitch in order to minimize ledging and maximize fatigue life. Finally, in this study, we reveal the sensitivity of the orientation of files with respect to the bending direction, which must be taken into account when designing, reporting, and interpreting test results under such loading conditions.

11.
Acta Stomatol Croat ; 56(4): 351-362, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36713275

RESUMEN

Objective: Effective tools and methods are applied during root canal retreatment to eliminate root canal obturation materials and preserve the initial root canal anatomy. The present study compared the efficacy of Reciproc, Neoniti, ProTaper, and Hedstrom files in the retreatment of curved root canals. Material and methods: In the present in vitro study, 100 root canals with 25‒45º curvatures were used. After the samples were initially prepared and examined by CBCT, the root canals were obturated with gutta-percha and randomly assigned to four groups (n=25). A retreatment was carried out in each group with NeoNiTi, ProTaper, Reciproc, and Hedstrom files. CBCT examinations were carried out again under the same conditions. The samples were evaluated at 3-, 6-, and 9-mm distances from the apex on the first and the second CBCT image for root canal transportation and remaining gutta-percha in the root canals. The time required for retreating each canal in each sample was recorded. One-way ANOVA and corresponding non-parametric tests were applied for data analysis. Results: The root canal transportation in the NeoNiTi group was lower than that in the other groups and significantly different from the ProTaper group (P<0.05). There was a remaining gutta-percha after retreatments in all the four groups, which was not statistically significant (P>0.05). Conclusion: Despite the fact that the NeoNiTi file produced less transportation than other file systems evaluated in the retreatment of curved root canals, all the files were very effective at the clinically acceptable levels.

12.
Proc Inst Mech Eng H ; 236(1): 121-133, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34479454

RESUMEN

The shaping and cleaning of the root canal are very important in root canal treatment. The excessive force and vibration during biomechanical preparation of the root canal may result in failure of the endodontic file. In this study, force and vibration analysis was carried out during root canal preparation. The samples of human extracted (premolar) teeth were provided by the College of Dental Science and Hospital. Endodontic instruments for reciprocating motion, such as the WaveOne Gold file system, had been used for root canal preparation. Force and vibration signals were recorded by dynamometer and accelerometer, respectively. The acquired signals were denoised using the db4 (SWT denoising 1-D) wavelet. Four levels of decomposition were carried out for each signal. The signal denoising technique was used to remove unwanted noise from the acquired signal. FESEM analysis was used to visualize the levels of severity of endodontic files during the cleaning and shaping of the root canal. In most of the cases, the failure occurred due to the improper use of the root canal instrumentation. The optimum amount of force was used to avoid the file failure and provided the proper instrumentation. The curve fitting regression model was used to find the interdependency between force and vibration.


Asunto(s)
Cavidad Pulpar , Vibración , Instrumentos Dentales , Humanos , Movimiento (Física) , Preparación del Conducto Radicular
13.
Odovtos (En línea) ; 23(2)ago. 2021.
Artículo en Inglés | LILACS, SaludCR | ID: biblio-1386526

RESUMEN

ABSTRACT: Fracture of an endodontic file inside a primary root canal is a rare but critical complication during the pulpectomy treatment, because the mechanical obstruction impedes the optimal cleaning and obturation of the pulp canal, compromising seriously the clinical outcome. This accidental event is mainly associated with over-use and excessive torque of intracanal files. Most clinicians opt to proceed with the extraction of the affected tooth followed by a space maintainer placement. Other practitioners attempt the non-surgical retrieval of the separated fragment through available proven techniques in permanent teeth; however, these methods may involve significant damage to the tooth and surround tissues. On the other hand, preservation of the metallic fragment might affect the treatment prognosis and interfere with the physiological root resorption.


RESUMEN: La fractura de una lima endodóntica dentro de un conducto radicular primario es una complicación rara aunque critica durante el tratamiento de pulpectomía, debido a que la obstrucción mecánica impide la limpieza y obturación óptimas del conducto pulpar, comprometiendo seriamente el resultado clínico. Este evento accidental está principalmente asociado con el sobreuso y torque excesivo de las limas dentro del conducto. La mayoría de los clínicos optan por realizar la extracción del diente afectado, seguido por la colocación de un mantenedor de espacio. Otros practicantes intentan la remoción no quirúrgica del fragmento separado a través de técnicas disponibles probadas en dientes permanentes; sin embargo, estos métodos pueden causar daños significativos al diente y tejidos circundantes. Por otra parte, la preservación del fragmento metálico puede afectar el pronóstico del tratamiento e interferir con el proceso de reabsorción radicular fisiológico.


Asunto(s)
Periodoncia/instrumentación , Obturación del Conducto Radicular , Instrumentos Dentales , Materiales de Recubrimiento Pulpar y Pulpectomía
14.
J Conserv Dent ; 23(1): 21-25, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33223636

RESUMEN

AIM: The present retrospective cross-sectional study aims to evaluate the incidence and factors associated with nickel-titanium hand file fractures in root canal-treated teeth in a tertiary care hospital of western India. METHODOLOGY: The diagnostic records of intraoral periapical (IOPA) radiographs were analyzed to check for file fractures in the root canal-treated teeth. As a part of standardized departmental protocol, Hand ProTaper Universal file system (Dentsply, India) was used for chemomechanical preparation for root canal treatment. The file fractures were analyzed with reference to age group, type of teeth, curvature of the canal, site of file fracture in the canal, length of file fracture, level of file fracture, distance of the file fracture from the apex, and obturation status of the file-fractured tooth. Chi-square test was applied to assess the significance difference between the tested groups. RESULTS: A total of 19,810 IOPA X-rays were screened and 2728 root canal-treated teeth were found and of these 2728 cases, 109 file-fractured teeth were observed. CONCLUSION: The total incidence of file fractures was 3.9/100 root canal-treated cases, and mandibular molars with severely curved canals (>25°) had shown the maximum incidence of file fractures.

15.
J Oral Biol Craniofac Res ; 10(1): 396-400, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31890492

RESUMEN

AIM: To develop the mathematical model for root canal preparation using Endodontic file. METHOD: The process of obturation consist of the filling of the root canal cavity using heated and softened gutta-percha to get the fluid tight seal in between the canal wall and filled gutta-percha. Any obturation process to perform before it requires the preparation of the root canal which involves the removing dead tissue, substrates and debris from the decayed root canal. The various geometric parameters viz. Taper, relative angle for orientation of cross-section between two planes, pitch and polar symmetry constant of the Endodontic file etc. Geometric parameters are derived. The various performance parameters like Endodontic file life assessment, cutting force components (tangential and normal), substrate removal rate, torque exerted by Endodontic file etc are also derived successfully. The Endodontic file life is estimated based on two approaches viz. speed and volumetric wear approach. CONCLUSION: The mathematical model described is helpful for the Endodontic experts, researchers, design engineers etc. However the applicability of the described mathematical model limited to assumption of study. The gap between root canal to be prepared and Endodontic file is zero while preparation. The Endodontic file weight, speed of rotation and substrate removal rate is assumed to be constant. The mathematical model for Endodontic file discussed above proved to be efficient tool for studying the root canal preparation. The various geometric parameters and the various performance parameters are derived.

16.
Radiol Case Rep ; 14(12): 1545-1549, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31719943

RESUMEN

A patient was referred to the Oral and Maxillofacial Imaging Division and the attending dental specialist suspected a foreign object at the anterior region of the maxilla. The region was scanned using Kodak 9000 3D cone-beam computed tomography (CBCT) extraoral imaging system (Carestream Health, Inc.) to determine the type and morphometric characteristic of foreign object. The CBCT images failed to determine the identity and nature of the foreign object. CBCT images were then exported to the Materialise Interactive Medical Image Control System (Mimics) software to evaluate whether this software can help in enhancing the visualization of the foreign object in the maxillofacial region. The findings showed that there was an improved visualization of the foreign body and the type of the object could be determined with certainty. The object was identified as an endodontic file and was clearly visible when visualized as a reconstructed 3D model in Mimics software. Although the identification of abnormalities has been dramatically improved using 3D scans, the visualization can be further enhanced using image processing software like Mimics.

17.
Restor Dent Endod ; 44(3): e31, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31485427

RESUMEN

OBJECTIVES: To compare the formation of dentinal defects using stainless-steel hand K-files (HFs), rotary files, reciprocating files, and Self-Adjusting File (SAF), when used for oval root canals. MATERIALS AND METHODS: One hundred and forty extracted human mandibular premolar with single root and oval canal were selected for this study. Oval canals were confirmed by exposing to mesio-distal and bucco-lingual radiographs. Teeth with open apices or anatomic irregularities were excluded. All selected teeth were de-coronated perpendicular to the long axis of the tooth, leaving roots segments approximately of 16 mm in length. Twenty teeth were left unprepared (control), and the remaining 120 teeth were divided into 6 groups (n = 20) and instrumented using HF (size 40/0.02), Revo-S (RS; size 40/0.06), ProTaper NEXT (PTN; size 40/0.06), WaveOne (WO; size 40/0.09), RECIPROC (RC; size 40/0.06), and the SAF (2 mm). Roots were then sectioned 3, 6, and 9 mm from the apex, and observed under stereomicroscope, for presence of dentinal defects. "No defect" was defined as root dentin that presented with no visible microcracks or fractures. "Defect" was defined by microcracks or fractures in the root dentin. RESULTS: The control, HF, and SAF did not exhibit any dentinal defects. In roots instrumented by RS, PTN, WO, and RC files exhibited microcracks (incomplete or complete) in 40%, 30%, 55%, and 50%, respectively. CONCLUSIONS: The motor-driven root canal instrumentation with rotary and reciprocating files may create microcracks in radicular dentine, whereas the stainless-steel hand file instrumentation, and the SAF produce minimal or less cracks.

18.
J Mech Behav Biomed Mater ; 90: 165-172, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30366307

RESUMEN

To evaluate the bending and torsional properties of four nickel-titanium endodontic files, we simulated and compared WaveOne® primary size 25 with 0.07 taper, WaveOne Gold® primary size 25 with 0.07 taper, Reciproc® primary size 25 with 0.08 taper, and Reciproc Blue® primary size 25 with 0.08 taper. Three-dimensional models were created using computer-aided design software and numerically analyzed in ANSYS® Workbench. Boundary conditions for the numerical analyses were based on the ISO 3630-1 specifications. The highest stress levels were recorded for WaveOne® and Reciproc®. Numerical results of the bending test showed that WaveOne Gold® is 86% more flexible than WaveOne® with a deflection of 3 mm. Reciproc Blue® was 42.31% more flexible than Reciproc® file with a deflection of 3 mm. The WaveOne® instrument withstood the highest stress under the torsion test, followed by Reciproc®, then Reciproc Blue® files. The stress under torsion in the WaveOne® and WaveOne Gold® files is reduced in a 51%. Regarding Reciproc® and Reciproc Blue® files, the stress under torsional moments remains very similar. Our results exposed a considerable difference in terms of stress tolerance between WaveOne® and WaveOne Gold®. However, Reciproc® files demonstrated a similar stress distribution. The results obtained through finite element analysis suggest that thermal treatment of files might improve their flexibility, increasing resistance during the preparation of highly curved canals. Also, the values obtained regarding the improvement of flexibility were in accordance with the manufacturer claims.


Asunto(s)
Aleaciones Dentales , Endodoncia , Análisis de Elementos Finitos , Ensayo de Materiales , Fenómenos Mecánicos , Níquel , Titanio
19.
Aust Endod J ; 45(2): 154-162, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30113735

RESUMEN

This study evaluated the effect of new motions of the motor TriAuto ZX2 on the cyclic fatigue of endodontic instruments. Vortex Blue 35.06 instruments were divided into four groups (n = 10) and tested for fatigue in a curved artificial canal (90° and 2 mm radius) using the following motions: continuous rotation (CR), Optimum Torque Reverse (OTR) set at 180° and the Optimum Glide Path (OGP), which was tested at 90° and 240°. The time to fracture (TTF) and the lengths of the fractured fragments were recorded. The mean TTF was significantly different among the groups (anova, P < 0.05): OGP 90° (213.39 ± 27.45), OTR 180° (121.24 ± 17.03), OGP 240° (45.24 ± 5.61) and CR (8.43 ± 1.27). Weibull analysis confirmed the shortest life expectancy for CR and the longest survival for OGP at 90°. The resistance to fatigue was affected by motions and pre-set angles. The proprietary movements that are currently available for endodontic instruments were classified according to their kinematics.


Asunto(s)
Fatiga , Titanio , Fenómenos Biomecánicos , Diseño de Equipo , Humanos , Preparación del Conducto Radicular , Rotación , Torque
20.
Artículo en Inglés | WPRIM (Pacífico Occidental) | ID: wpr-761307

RESUMEN

OBJECTIVES: To compare the formation of dentinal defects using stainless-steel hand K-files (HFs), rotary files, reciprocating files, and Self-Adjusting File (SAF), when used for oval root canals. MATERIALS AND METHODS: One hundred and forty extracted human mandibular premolar with single root and oval canal were selected for this study. Oval canals were confirmed by exposing to mesio-distal and bucco-lingual radiographs. Teeth with open apices or anatomic irregularities were excluded. All selected teeth were de-coronated perpendicular to the long axis of the tooth, leaving roots segments approximately of 16 mm in length. Twenty teeth were left unprepared (control), and the remaining 120 teeth were divided into 6 groups (n = 20) and instrumented using HF (size 40/0.02), Revo-S (RS; size 40/0.06), ProTaper NEXT (PTN; size 40/0.06), WaveOne (WO; size 40/0.09), RECIPROC (RC; size 40/0.06), and the SAF (2 mm). Roots were then sectioned 3, 6, and 9 mm from the apex, and observed under stereomicroscope, for presence of dentinal defects. “No defect” was defined as root dentin that presented with no visible microcracks or fractures. “Defect” was defined by microcracks or fractures in the root dentin. RESULTS: The control, HF, and SAF did not exhibit any dentinal defects. In roots instrumented by RS, PTN, WO, and RC files exhibited microcracks (incomplete or complete) in 40%, 30%, 55%, and 50%, respectively. CONCLUSIONS: The motor-driven root canal instrumentation with rotary and reciprocating files may create microcracks in radicular dentine, whereas the stainless-steel hand file instrumentation, and the SAF produce minimal or less cracks.


Asunto(s)
Humanos , Diente Premolar , Cavidad Pulpar , Dentina , Mano , Técnicas In Vitro , Diente
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