Endodontic Files Research Articles

Oval Root Canals Prepared With Two Different Endodontic Rotary Files: An In Vitro Study Comparing the Incidence of Dental Defects.

This study aims to investigate and compare the establishment of dentinal cracks during root canal preparation using a stereomicroscope and a scanning electron microscope (SEM). Sixty removed human mandibular premolars were separated into three groups of 20: two experimental and one control. Within the randomized controlled experimental groups, root canals were constructed. Group I: the Waldent walflex file and Group II: the Trunatomy (TRN) file. Group III: the control group received no preparations. The surfaces of the roots werechecked for dentinal cracksusing a stereomicroscope and SEM following sectioning at 3, 6, and 9 mm from the apex.The Chi-square test was used to examine the data. ​​​​​​ In the control group, no fissures appeared. Cracks in Waldent Walflexwere almost 66.7%between the 3mm and 6mm range. At both the 6 mm and 9 mm levels, there was no statistically significant difference between the experimental groups (P > 0.05).Defects were found to be substantially higher in the apical region of samples than in the median and coronal sections. Dentinal fissures were created by every rotary file used in the tests. There were more flaws in the Waldent Walflex file group than in the Trunatomy file group.

Modeling the Response of NiTi Endodontic Files Subjected to Cyclic Non‐proportional Loading

AbstractNickel‐Titanium (NiTi) endodontic files have emerged as valuable tools for root canal treatment due to their high strength and flexibility. During treatment, the files are rotated in the bent configuration of the root canal, which leads to cyclic non‐proportional loading. With the goal of understanding the mechanical response of NiTi endodontic files and to allow for an enhanced design of these structures, a constitutive model for shape memory alloys is developed. This model incorporates several of the features present in SMAs relevant for the mechanical response of endodontic files including: transformation, reorientation, yield plasticity, functional fatigue, tension‐compression asymmetry and internal loops. The model is implemented in Ansys using a small strain formulation and extended to finite strains using the nonlinear geometry algorithm in Ansys. Validation of the model is performed by simulating a cyclic torsional experiment from the literature using a simplified file geometry. Finally, the model is applied to simulate a simplified file under torsional rotation in a bent configuration. The results illustrate that the endodontic file develops a torsional oscillation during the course of the cyclic loading, which is directly associated with an increase in residual stresses. Furthermore, the torsional oscillation leads to higher values of the martensite volume fraction and stress.

Fracture incidence of waveone gold and reciproc blue files when used in up to three clinical cases: a prospective study

Objective: Reuse of endodontic files remains an open issue in clinical practice. This study was designed to evaluate the fracture strength of WaveOne Gold (Dentsply Maillefer, Ballaigues, Switzerland) and Reciproc Blue (VDW, Munich, Germany) files with successive reuse for root canal shaping in up to three molars. Material and Methods: Prospective clinical study carried out by five calibrated endodontists who treated 384 molars (1291 canals) with a curvature <45° over a 12-month period. A total of 128 instruments were used (64 Reciproc Blue and 64 WaveOne Gold). Each instrument was used to treat three posterior teeth. After each use, the instruments were observed under an operating microscope at 8× magnification. Data were tabulated and a chi-square test was applied. Significance was accepted at the 5% level. Results: Two instruments (one from each group) separated, both on the third use and during instrumentation of a mandibular first molar. In other words, instrument separation occurred in 0.52% of teeth and 0.16% of treated root canals. Conclusions: There was a low incidence of instrument fracture when reciprocating files were used for up to three endodontic treatments in molars.

Novel Pin Method for Labeling Surfaces on a Gross Specimen

At present, surgeons and pathologists mark surfaces on a gross specimen by means of sutures of variable lengths or by inking them with different colors. However, both the existing methods have certain disadvantages associated with them such as tissue damage and interference with staining characteristics. Herein, we have introduced a novel “pin method” for labeling surfaces on a gross specimen to overcome the drawbacks of existing methods. The method involves marking different surfaces on a gross specimen using pin-like instruments such as table pins, endodontic files, and spreaders having colored knobs to mark the corresponding surfaces. The method is efficient and effective for labeling surfaces on a gross specimen, requiring minimal time and effort on the part of the surgeon, as compared to the existing methods.

Evaluation of postoperative pain with new heat-treated rotary and reciprocating nickel-titanium files: A randomized controlled clinical trial.

A special heat-treated endodontic file (TruNatomy) was recently introduced with the claim of superior flexibility to enhance dentin preservation. The aim of the present study was to assess postoperative pain in single-visit root canal treatment with this newly introduced file, comparing it with other contemporary reciprocating and rotary file systems. One hundred seventy patients with acute irreversible pulpitis in maxillary premolars were randomly assigned to four experimental file systems: TruNatomy, HyFlex EDM, EdgeFile, and ProTaper Gold. Pre- and postoperative pain scores were assessed with 10-point visual analog scale. Data were statistically analyzed using Kruskal-Wallis test. TruNatomy file system had significantly the highest postoperative pain incidence (53.8%), while the EdgeFile system had significantly the least postoperative pain incidence (24%) and 24-h pain score. The present study demonstrated that the reciprocating multiple-file system, EdgeFile, had significantly reduced postoperative pain incidence compared to other heat-treated rotary nickel-titanium file systems.

Comparative evaluation of pericervical dentin preservation and fracture resistance of root canal-treated teeth with rotary endodontic file systems of different types of taper - An in vitro study.

The aim of this study was to evaluate and compare the pericervical dentin preservation and fracture resistance of root canal-treated teeth with rotary endodontic file systems of different types of taper. Thirty-two single-rooted human-extracted premolars were used. They were mounted in wax, and preoperative cone-beam computed tomography (CBCT) scans were taken with 11 × 8 Field of view (FOV). The evaluation of the pericervical dentin thickness was done at the cementoenamel junction level. After pre-CBCT, the 32 samples were divided into four groups (n = 8) - Group A: fixed tapered hand files, Group B: variable regressive tapered TruNatomy, Group C: progressive tapered ProTaper Gold, and Group D: fixed tapered HyFlex EDM. Following instrumentation, postoperative CBCT scans were taken to evaluate pericervical dentin thickness. Obturation was done and access cavity was restored with composite. Fracture strength was checked for all the samples using "universal testing machine" until fracture, and calculated in newtons (N). Student's t-test and ANOVA test, along with Tukey's post hoc analysis, were used for comparing mean values between the groups, and P < 0.05 was considered statistically significant. The results of this study showed that there is no statistically significant difference in preserving pericervical dentin with file system of different types of taper and fracture resistance between the groups. Within the limitations of the study, it was concluded that different types of file taper systems used for root canal preparation have no significant effect on the preservation of pericervical dentin and fracture resistance of teeth.

Evaluation of the efficacy of TruNatomy, ProTaper retreatment, and RaCe file systems in retreatment of moderately curved mandibular molars: An in vitro study.

Endodontic retreatment is the first line of treatment in cases of failed primary endodontic treatment. Although associated with challenges such as incomplete removal of obturating material, increased clinical time, and extrusion of apical debris, endodontic retreatment still has considerable success rate in the general population. The aim of this study was to evaluate and compare the efficacy of TruNatomy, ProTaper retreatment, and RaCe file systems to remove the obturating material, time taken to remove the obturating material, and apical extrusion of debris using cone-beam computed tomography (CBCT). In vitro study. Forty-five moderately curved mesiobuccal roots of the mandibular molars were instrumented up to #25, 4% taper and obturated with bioceramic sealer and lateral compaction technique. Teeth were divided randomly into three groups (n = 15). Teeth were retreated with TruNatomy, ProTaper retreatment, and RaCe file systems, respectively. Preretreatment and postretreatment CBCT scans were recorded and percentage of obturating material removed was calculated. Time taken to remove the obturating material and apical extrusion of debris was noted. Descriptive statistics including percentage, mean, standard deviation, Tukey's post hoc test, Kruskal-Wallis test, and Mann-Whitney Post hoc test were used. The total time needed for the removal of obturating material was comparatively shorter in the RaCe group, followed by the ProTaper retreatment group and TruNatomy group (P < 0.001). TruNatomy files were significantly better in removing the obturating material than the ProTaper retreatment files (P = 0.04). Statically, no difference between RaCe and TruNatomy files was noted. Apically extruded debris was more in the TruNatomy group than in the RaCe and ProTaper retreatment groups (P = 0.01). All tested endodontic files were effective in removal of obturating material, although none could completely remove the filling material and no system could completely eliminate apical extrusion.

Influence of Coronal Flaring on the Shaping Ability of Two Heat-Treated Nickel-Titanium Endodontic Files: A Micro-Computed Tomographic Study.

Nickel-titanium (NiTi) usage is associated in endodontics with some complications including canal transportation. Centering ability of a NiTi file is the ability to stay centered in the root canal system during instrumentation. Any undesirable deviation from the natural canal path is indicated as canal transportation. A possible strategy to improve the centering ability of NiTi instruments is the pre-enlargement of the coronal third of the root canal to minimize coronal interferences. This procedure is known as coronal flaring. The aim of this study was to perform a micro-computed tomographic (micro-CT) evaluation of the effect of coronal flaring on canal transportation and centering ability of two heat treated nickel-titanium rotary instruments, 2Shape (Micro Mega, Besançon, France) and HyFlex CM (Coltène Whaledent, Altstätten, Switzerland). Thirty extracted mandibular molars with two independent mesial canals were selected and randomly instrumented (n = 15 canals) with One Flare (Micro Mega, Besançon, France) before HyFlex CM, HyFlex CM (without coronal flaring), One Flare before 2Shape and 2Shape (without coronal flaring). One Flare (Micro Mega, Besançon, France) was introduced 4 mm below the canal entrance for canals prepared with coronal flaring. HyFlex CM and 2Shape were used accordingly to manufacturers’ instructions. New files were used for each canal. During and after instrumentation, irrigation procedures were performed. Micro-CT images were obtained pre- and post-preparation to measure and record root canal transportation and centralization. They were reconstructed from root apex to canal orifices, generating approximately 1000 sections per specimen. The anatomical thirds were determined by dividing the number of cross-sectional slices by three. Root canal transportation and centralization were determined by Gambil method, and the mean values were analyzed by repeated measures analysis of variance followed by multiple comparisons of Bonferroni to compare the different instrumentations procedures and the root thirds (p < 0.05). As for root canal transportation, 2Shape reported significantly higher values compared to HyFlex CM in the cervical region independently from the coronal flaring. In the apical region, 2Shape caused significantly minor canal transportation when used with coronal flaring with compared with the absence of coronal flaring. Regarding the centralization, HyFlex CM showed higher values than 2Shape in the cervical, independently from coronal flaring. In the apical region, 2Shape with coronal flaring exhibited significant major centering ratio, compared with not. Within the limitations of this study, coronal flaring reduced canal transportation and improved centralization of the 2Shape files in the apical section while it had no significant influence on shaping ability of the HyFlex CM instruments. Coronal flaring could represent a valid strategy to improve the shaping ability of NiTi files knowing that its benefit could be influenced by the shaping file used.

Dental health-care professionals' awareness and knowledge of sterilization and disinfection practices for new, unused endodontic files and gutta-percha in Jeddah, Saudi Arabia

Introduction: The proper protocol for the sterilization of instruments is essential in dental practice; especially because some clinicians think that new files directly from the manufacturers are already sterile and can be used directly on patients without the standard sterilization. Therefore, the aim of this study is to analyze the dental levels of professionals and their auxiliary staffs concerning awareness, knowledge, attitudes, and behaviors about sterilizing endodontic instruments and gutta-percha. Materials and Methods: This cross-sectional study was conducted in Jeddah, Saudi Arabia, using an online, randomly distributed survey for dental health-care practitioners. The survey questions were about the participants' demographics, knowledge, attitudes, and behaviors about sterilization techniques for endodontic files and gutta-percha. Data analysis consisted of simple descriptive statistics presented in frequency tables and percentages. Results: Of the 197 dental health-care practitioners surveyed, the majority (84.7%) stated that they use files directly from the manufacturer's packages, while only 15.3% reported sterilizing the new endodontic files before using them with patients. As for gutta-percha, 23.4% of the participants answered that they disinfected it before obturation. About 60% of the participants were unaware that the sterilization's expiry date was printed on the endodontic file packages. Conclusions: The results indicated that the majority of dental practitioners and students do not practice an effective sterilization protocol for endodontic files and gutta-percha. Based on these results, this study recommends that more education about sterilization protocols should be added to the infection control curriculum.

Perception of Dental House Officers regarding Endodontic File Separation during Endodontic Treatment.

Despite of having improved endodontic file designs as well as the reinforced metal alloy file structure, intracanal endodontic file separation (EFS) is still a very problematic and worrisome dental incident, which usually occurs without any visible signs of permanent deformation. Further, there have been conflicting reports regarding the clinical significance of leaving separated files within root canals. The aim of this study was to look into the current perceptions and awareness about file separation during endodontic treatment among the dental house officers (DHOs). A novel validated questionnaire comprising of 15 close-ended questions was distributed anonymously via Google Forms through email to 1100 DHOs across Pakistan. The questionnaire consisted of two parts: the first component (Section I) collected demographic data and the second component (Section II) investigated the causes of EFS during root canal treatment. Following the completion of socioeconomic information, including age and gender, the DHOs were asked to answer a few questions about the various reasons for endodontic instrument fracture. A total of 800 responses were recorded, with an effective rate of 72.8%. The majority of the DHOs (p value < 0.001) perceived that endodontic instrument fracture occurred in the posterior (61.5%) and apical third of the canal (50.5%) and in older permanent dentition (67.3%), possibly due to patient anxiety (62%). Better choice of instrument (61.15%), operators' experience (95.3%), knowledge (87.5%), and proper root canal cleaning (91.1%) are believed to be the vital steps in reducing endodontic file separation/fracture. Furthermore, majority of them (p value < 0.001) perceived that stainless steel was a superior alloy for filing instruments. Manual files tend to be more prone to fractures due to repeated use than rotary files. This study demonstrated that young DHOs had adequate knowledge and awareness regarding the potential predisposing factors and handling techniques for EFS. This study thereby provides an evaluating tool to access the insights of the current perceptions and awareness of DHOs concerning EFS.

Canal centering ability of various file systems during endodontic treatment and re-treatment: A systematic review

Introduction: The canal-centering ability of an endodontic file is the ability of a file to maintain its path centered through the root canal without causing transportation. Various researchers have attempted to compare the canal-centering ability of the different file systems used routinely in endodontic practice. The present systematic review aimed to comparatively analyze the canal-centering ability of the various endodontic file systems. Methods: A systematic search was performed using the keywords ‘Canal centering ability’ and ‘Endodontics’ across the databases Medline, PubMed, PubMed Central, Web of Science Citation Index Expanded, and Google Scholar to identify studies related to canal-centering ability of various file systems in endodontic treatment or re-treatment in English language without any restriction for the date of publication. Results: A total of 22 studies were identified, most of which utilized human extracted teeth for analyzing the canal-centering ability. The mesial root of the mandibular first molars was most commonly used, with the mesiobuccal canal being commonly chosen to compare the canal centering ability. No significant difference was found between the canal-centering ability of reciprocating and continuous rotary file systems. The individual conclusions regarding comparisons made between respective file systems in each study have been summarized in the text. Conclusion: The canal-centering ability of various endodontic file systems does not depend on the speed or motion of the file but is a derivative of multiple factors including geometry, composition, size, and shape of the files. Findings from the present systematic review would serve as a guide for an appropriate selection of the files to be used in cases with challenging canal morphology requiring endodontic treatment.

Assessment Of the Obturation Quality of Three Different Endodontic Rotary Files Using Cbct

Assessment Of the Obturation Quality of Three Different Endodontic Rotary Files Using Cbct

Evaluation of Root Dentin Removal and Apical Debris Extrusion during Root Canal Preparation Related to the Different Endodontic Access Cavities: An In-vitro Study

Introduction: The restricted access cavity and the remaining roof of the pulp chamber may change the angle at which the instrument enters the root canal, which could have an impact on the effectiveness of chemo-mechanical canal preparation, potentially leading to endodontic mishaps. Aim: To evaluate the effect of the Traditional Endodontic Cavity (TEC) and Conservative Endodontic Cavity (CEC) on the amount of Root Dentin Removal (RDR) and the related Apical Debris Extrusion (ADE) in the curved root canals prepared with ProTaper Next (PTN) and TruNatomy (TN). Materials and Methods: The in-vitro study included a total of 120 extracted human mandibular molars, separated into four groups (n=30) based on the type of endodontic cavity and file used: TEC-TN, CEC-TN, TEC-PTN, and CEC-PTN. Before biomechanical preparation, Cone Beam Computed Tomography (CBCT) scans were taken. During the preparation, apically extruded debris was collected in Eppendorf tubes. After canal preparation, a post-CBCT scan was performed, and the RDR was evaluated by comparing the pre- and post-CBCT scans. To determine the amount of ADE, the weight of the clear tubes was subtracted from the weight of the tubes containing the debris. The data were analysed using one-way analysis of variance and post-hoc Tukey test. The significance level was set at p&lt;0.05. Results: Analysis and comparison of four groups each with n=-30 extracted mandibular molars was done in the present study. The CEC-PTN group showed the highest total RDR of 0.32. Additionally, the CEC-PTN group produced the highest ADE with statistically significant differences between the TECTN, CEC-TN, and TEC-PTN groups (p&lt;0.05). Conclusion: The CEC causes engagement of the rotary instrument with the dentinal wall, leading to RDR, debris production, and ultimately more ADE compared to TEC. The TN file caused less RDR and ADE in both endodontic access cavities compared to the PTN file.

Modern Endodontic Rotary File Systems - A Review

Endodontic treatment approaches have advanced dramatically in recent decades due to the introduction of various novel techniques and devices. Clinicians should be versed in all the properties and capabilities of the devices that can be utilised to perform root canal therapy for choosing the ideal rotary file. A number of nickel-titanium root canal shaping devices have been developed over the years. NiTi rotary systemsrsquo therapeutic efficacy is influenced by numerous factors and physical features. Clinical experience handling qualities safety and case results should ultimately determine the fate of an instruments design. This article outlines the distinct properties present applications and most recent advances in endodontic rotary files.

Comparative evaluation of shaping ability of trunatomy rotary endodontic file versus different rotary endodontic file systems

Comparative evaluation of shaping ability of trunatomy rotary endodontic file versus different rotary endodontic file systems

Influence of concentration, irrigation method, and root canal third on intratubular penetration of sodium hypochlorite - a broad statistical analysis.

The permanence of microorganisms in the root canal system represents the main cause of endodontic failure. Considering the impossibility of effective action of the endodontic files in ramifications of the main canal and mainly inside the dentinal tubules, a better understanding of the irrigation dynamics to enhance endodontic prognosis is essential. Objective: To evaluate the depth of intratubular penetration values of sodium hypochlorite (NaOCl) (dependent variable) by comparing different concentrations, methods of irrigation, and root canal thirds (independent variables) and to investigate the existence of interactions among them, capable of influencing the dependent variable. 40 roots from extracted human maxillary central incisors were stained and instrumented according to four irrigation protocols (n. 10): conventional irrigation (CI) at each use or change of instrument, and final irrigation with 5ml of 2.5% or 5.25% NaOCl, with or without passive ultrasonic irrigation (PUI), respectivelly. Measurements based on stereomicroscopic images were obtained, and the data were subjected to statistical analysis (p< 0.05). The highest depth values of intratubular penetration of NaOCl were observed in the cervical third, at 5.25%, and by PUI. When only two independent variables were analyzed in association, the highest penetration depth values of NaOCl were obtained at 5.25%, regardless of irrigation method, at 5,25%, in the cervical third, and; in the cervical third, despite of irrigation method. Considering the three independent variables simultaneously, the highest depth values of intratubular penetration of NaOCl were observed in the cervical third, at 5.25%, no matter the irrigation method. The interaction between the independent variables on the penetration depth values of NaOCl was only confirmed considering the irrigation method and root canal third. Intratubular penetration of NaOCl was influenced by the three independent variables individually and when the irrigation method and root canal third were considered simultaneously. Key words:Dentinal tubules, Depth, Disinfection, Irrigation, Root canal system, Sodium hypochlorite.

Assessment of the amount of apically extruded debris using three different reciprocating single endodontic file systems

Introduction: This study aimed to assess the amount of apical extrusion of debris after root canal instrumentation with three different reciprocating single endodontic file systems including R-motion, Edge One Fire, and Reciproc Blue. Methods: Forty-five human upper first molars that were extracted for periodontal reason included in the study and randomly assigned among three study groups (n = 15). Reciproc Blue, R-motion, and Edge One files were used to instrument the palatal root. Amount of apical extrusion of debris was assessed using the empty tube model of Myers and Montgomery. Data were analyzed blindly via one-way ANOVA and the Tukey post hoc test using R. Results: There was statistically significant difference among study groups (p &lt; 0 .001). Post hoc test showed nonsignificant difference among Edge One and Reciproc Blue groups (p = 0.106). The difference between R-motion and Reciproc Blue was marginally significant (p = 0.055). Conclusion: Within the limitations of this study, R-Motion showed the most amount of apically extruded debris followed by Reciproc Blue and Edge One.

Prevalence of pulp and periapical diseases in the endodontic postgraduate program at the national autonomous University of Mexico 2014-2019.

Investigations on the prevalence of pulp and periradicular diseases in Mexican population produced few studies, conducted to specific age population. Considering the importance of epidemiological investigation. The aim of this study was to estimate the prevalence of pulp and periapical pathologies and their distribution according to sex, age, affected teeth, and etiological factors found in patients the DEPeI, FO, UNAM Endodontic Postgraduate Program during the period 2014-2019. The data collected were from the records of the Single Clinical File of patients treated at the Endodontic Specialization Clinic, DEPeI, FO, UNAM, period 2014-2019. The following variables were recorded for each endodontic file: diagnosed pulp and periapical pathology, sex, age, affected tooth, and etiological factor. Descriptive statistical analysis was performed with 95% CI (Confidence intervals). Of all the registers reviewed, irreversible pulpitis (34.58%) and chronic apical periodontitis (34.89%) proved to be the most prevalent pulp and periapical pathologies, respectively. The female sex predominated (65.36%). The age group that requested the most endodontic treatment, according to the records reviewed, was 60 or older (36.99%). The most treated teeth were the upper first molars (24.15%) and lower (36.71%), and the most prevalent etiological factor was dental caries (84.07%). Irreversible pulpitis and chronic apical periodontitis were the most prevalent pathologies. The predominant sex was female, and the age group was 60 years or older. The first upper and lower molars were the most endodontically treated teeth. The most prevalent etiological factor was dental caries. Key words:Pulp pathology, periapical pathology, prevalence.

Cryotherapy: A paragon for endodontic therapy

Patients undergoing endodontic treatment may develop post-endodontic pain, leading to pain and inflammation. Cryotherapy is a remedial procedure widely used in the field of medicine and dentistry, considered to be effective at reducing edema, pain, bleeding and inflammation. In endodontics, it is relatively new and may be beneficial in the prevention and treatment of post-endodontic pain. Additionally, cryogenic treatment is considered a key factor in strengthening rotary NiTi endodontic files. Further well-designed clinical studies will be conducted to establish the effective use of cryotherapy in the control of post-endodontic pain in clinical practice. This article describes the concept of cryotherapy and its potential clinical implications in endodontics.

Comparative assessment of cleaning efficacy of Kedo-SH manual and Kedo-S rotary endodontic files in deciduous molars - an in-vitro study

Introduction: Preparation of root canals in deciduous molars can be challenging due to their inherent anatomy. Endodontic files were introduced recently for exclusive use in deciduous dentition. Hence, the aim of the present comparative study was to assess the cleaning efficacy of manual and rotary endodontic files in deciduous molars. Methods and materials: Sixty canals of recently extracted deciduous molars were selected which did not have more than one-third of their root length resorbed. Following working length determination, India ink dye was injected into all the canals. They were arbitrarily allocated into two groups; Group I: Kedo-SH manual files (n=30) and Group II: Kedo-S rotary files (n=30), for the purpose of instrumentation. The root canals were cleared of debris and sections prepared. The sections were examined under a stereomicroscope under 40X magnification for removal of India ink at different thirds and given scores. Data was subjected to statistical analysis using Student t test and ANOVA. Level of significance was 5%. Results: Both file systems resulted in superior cleaning of the coronal and apical section of the canals. The average scores for coronal and middle sections of the root canals with Kedo-SH manual files (9.5 ± 8.062; 10.75 ± 10.31, respectively) were significantly higher than that of Kedo-S rotary files (5± 6.63; 6.05 ±7.5, respectively) (p&lt;0.05). Conclusion: Root canals prepared with Kedo-S rotary files showed significant superiorly clean root canals than those prepared using Kedo-SH manual files. Keywords: Kedo-S, Kedo-SH files, deciduous molars, pulpectomy, root canal instrumentation.