Single-file Systems Research Articles

Comprehensive Review and New Analysis Software for Single-file Pedestrian Experiments

This paper offers a comprehensive examination of single-file experiments within the field of pedestrian dynamics, providing a thorough review from both theoretical and analytical perspectives. It begins by tracing the historical context of single-file movement studies in pedestrian dynamics. Then, the significance of understanding the fundamental relationships among density, speed, and flow in pedestrian dynamics through the lens of simple single-file systems is explored in depth. Furthermore, we investigate various traffic systems involving human or non-human entities such as ants, mice, bicycles, and cars, and provide insights. We explore the types of experimental setups, data collection methods, and influential factors that affect pedestrian movement. We also define and explain the common concepts concerning single-file movement, particularly in experimental research. Finally, we present a Python tool named ``SingleFileMovementAnalysis'' designed for analyzing single-file experimental data, specifically head trajectories. This tool provides a cohesive approach to preparing and calculating movement metrics like speed, density, and headway. The article aims to stimulate further research and underscore the areas where future researchers can contribute to advancing and enhancing single-file studies.

Comparative Evaluation of the Effectiveness of Rotary and Reciprocating Single File Systems on Postoperative Pain After Biomechanical Preparation in Patients With Chronic Apical Periodontitis: A Randomized Clinical Trial

Comparative Evaluation of the Effectiveness of Rotary and Reciprocating Single File Systems on Postoperative Pain After Biomechanical Preparation in Patients With Chronic Apical Periodontitis: A Randomized Clinical Trial

Comparative evaluation of remaining dentin thickness and root canal transportation in curved canals with newer nickel–titanium single and multiple rotary file systems: A cone-beam computed tomography study

Abstract Context: The purpose of this study was to evaluate and compare the remaining dentin thickness and root canal transportation of WaveOne GOLD, XP-endo Shaper, and GenEndo file systems to assess their performance in curved canals using cone-beam computed tomography (CBCT) imaging. Materials and Methods: Seventy-five extracted maxillary first molars were selected with a curvature ranging between 15° and 30°. The samples were allocated into three groups (n = 25) and shaped using WaveOne GOLD, XP-endo Shaper, and GenEndo files. CBCT images were captured before and after instrumentation. Statistical Analysis: The remaining dentin thickness and root canal transportation were measured at 3, 5, and 7 mm from the apex in both mesiodistal and buccolingual directions. The data were statistically analyzed using one-way ANOVA followed by Tukey’s post hoc test. Results: GenEndo file system demonstrated greater preservation of remaining dentin thickness and resulted in less root canal transportation compared to the WaveOne GOLD and XP-endo Shaper systems across all three levels. Conclusions: GenEndo file system which comprises multiple files has removed less amount of dentin and canal transportation when compared to single file systems, i.e., WaveOne GOLD and XP-endo Shaper file systems.

Impact of using single-file reciprocating system on the quality of root canal treatment treated by undergraduate students

BackgroundThis study aimed to evaluate the use of a single-file reciprocating system on the technical quality of root canal filling and treatment by radiographic assessment of cases treated by undergraduate dental students. Materials and methodsThis was a retrospective cross-sectional clinical study of endodontically treatments conducted by fourth-year undergraduate students during the academic year 2021–2022. Root canal preparation was performed using the WaveOne Gold system with matching single-cone gutta-percha. The collected data included sex, tooth position, number of canals, and treatment time (first or second semester). The quality of the root canal filling was assessed based on the root canal filling length, density, and taper. The presence of ledges, apical transportation, perforation, and instrument separation were recorded. Data were analyzed using SPSS version 28. Chi-square tests were used, and the statistical significance level was set at P < 0.05. ResultsA total of 601 teeth were included. The length of the root canal filling was adequate in 93.51 % of the teeth, underfilled in 2.82 %, and overfilled in 3.66 %. The density and taper were adequate in 96.5 % and 98.16 % of the teeth, respectively. There were no significant differences among the parameters of length, taper, density, or procedural errors relative to the arch type. However, there was a significant difference between the anterior and premolar teeth in terms of taper, density, and overall quality of the root canal filling. The overall quality of root canal treatment was acceptable in 527 teeth (87.68 %), with no significant difference between teeth (P = 0.256). ConclusionThe quality of root canal treatment performed by undergraduate students using a single-file reciprocating system is good or acceptable.

Assessment of Vertical Force Generated with Single File Systems during Shaping of Constricted Root Canals.

This study aimed to evaluate the shaping force generated with OneShape (OS) and HyFlex EDM (HEDM) systems designed for single file shaping, in comparison with ProTaper Next (PTN). Maxillary premolar teeth received access cavity preparation and their canals were shaped with OS, HEDM, or PTN to size 25 according to manufacturer's instructions with consistent pressure on the files to give a gentle "in-and-out" movements of 2 mm amplitude. The canal shaping was completed with a total of three insertions. After each insertion, 1% NaOCl irrigation and recapitulation with K-file size 15 were performed. The vertical shaping force was measured using a force gauge (M5-20 Advanced Digital Force Gauge; Mark-10 Corporation, NY). The shaping time was analyzed by using a one-way analysis of variance (ANOVA) test and differences between the mean apical and coronal maximum force values were analyzed using the Kruskal-Wallis and Mann-Whitney U tests. The level of significance was set as 0.05. The magnitude of the vertical forces increased with successive advancements of the instruments within the canal. During canal shaping procedures in all groups, the apical and coronal maximum force values of the OS and HEDM ranged from 2.5 to 7.2 N and 1.3 to 2.9 N, respectively. PTN generated the lowest maximum apical forces during the second and third insertions (p < 0.05). HEDM generated significantly less maximum coronal forces than both OS and PTN during the first insertion while the use of OS was associated with the highest amount of force values in the second and third insertions (p < 0.05). In terms of shaping time, no significant differences were detected among the three tested systems (p = 0.606). The tested single file systems were associated with higher shaping forces in the apical direction that were significant in the second and third insertions.

Postoperative Pain Following Single Visit Root Canal Treatment With Reciproc Blue And Hyflex EDM Instrumentation; A Prospective Randomized Clinical Trial

Objective: Single file systems with continuous rotation or reciprocation produced with many new technologies promising in terms of postoperative pain. The aim of this study was to investigate the efficacy of using novel Reciproc Blue (RBlue) and HyFlex EDM (HEDM) files on postoperative pain after single visit root canal treatment. Materials and Methods: 72 patients with asymptomatic pulp necrosis in mandibular molar and premolar teeth were included. The root canals were prepared using HEDM (n=29) or RBlue (n=28) and hand-instruments (n=15) in single visit. Pain presence using verbal rating scale (VRS) and analgesic intake were recorded after 24h, 48h, 72h and 7 days. Results: Postoperative pain at 24h and 48h was statistically higher at RBlue group than HEDM and control groups (p0.05).There was no difference between groups in terms of analgesic intake (p&gt;0.05). RBlue files were associated with higher incidence of postoperative pain and higher VRS scores than HEDM and hand-instruments. Conclusion: RBlue files working with reciprocating motion caused much more postoperative pain than HEDM files and manual files.

Comparative evaluation of remaining dentin thickness using single file, two file, and multiple rotary file system - An in vitro CBCT study.

Endodontic success hinges on a multifactorial interplay, with meticulous canal shaping, proper disinfection, and three-dimensional obturation being paramount. Among these factors, the amount of dentin remaining after instrumentation directly influences the biomechanical resilience and longevity of the tooth. This study aims to evaluate the impact of various rotary instrumentation systems, including single-file, two-file, and multiple-file configurations, on the remaining dentin thickness (RDT) following canal preparation. This was an in vitro study, original research article. Sixty mandibular premolar human extracted teeth were decoronated at the cementoenamel junction with a diamond disc. Samples were randomly assigned to three groups using a simple random sampling technique (n = 60). Group I - Single-file system (One Curve, MicroMega) (n = 20), Group II - Two-file systems (2Shape, MicroMega) (n = 20), and Group III - Multiple-file system (Hero Gold, MicroMega) (n = 20). Preoperative cone-beam computed tomography (CBCT) scans were obtained after the sample was mounted on a modeling wax sheet. The biomechanical preparation of canals followed the manufacturer's protocols for every system. Postoperative CBCT scans were obtained. Pre- and postoperative scans were compared at standardized depths (4 mm, 7 mm, and 11 mm) within the canals (coronal, middle, and apical thirds), allowing for a comprehensive assessment of RDT throughout the canal. According to one-way ANOVA, the highest mean was seen in Group I, followed by Group II and Group III. Hence, a statistically significant difference was found between all the groups. Post hoc Tukey's test was done for intergroup comparison. A single-file system preserved more dentin with less aggressive cutting compared to two-file and multiple-file systems.

A quantitative comparison of apically extruded debris during root canal preparation using NiTi full-sequence rotary and single-file rotary systems: An in vitro study

ABSTRACT Aim: The purpose of this study was to compare quantitatively the apically extruded debris during root canal preparation using NiTi full-sequence rotary and single-file rotary systems. Methods: Sixty extracted mandibular premolar teeth with single canals and similar lengths were used and divided into four groups. Groups A and B are NiTi full-sequence rotary systems and Groups C and D are single-file rotary systems. In Group A, the canals were prepared using V-Taper 2H file (up to 25/0.06), Group B: TruNatomy file (up to 26/0.04), Group C: OneShape file (25/0.06), and Group D: OneCurve file (25/0.04). The initial weight of each Eppendorf tube to be used was calculated using an analytical balance before instrumentation. After instrumentation, the tubes were then stored for 15 days in an incubator at 37°C. The Eppendorf tubes were weighed again to determine their final weight which contained the extruded debris. The data were statistically analyzed using a one-way ANOVA test and Tukey’s post hoc test. Results: The OneCurve single-file system resulted in statistically significant less debris extrusion than the OneShape single-file system, TruNatomy multifile system, and V-Taper 2H multifile system (P &lt; 0.001). Among the full-sequence rotary file systems, the TruNatomy rotary file system produced statistically significantly less debris extrusion than the V-Taper 2H rotary file system (P = 0.01). Conclusion: All the instrumentation systems caused apical extrusion of debris. OneCurve system showed least debris extrusion, followed by OneShape, TruNatomy, and V-Taper 2H systems. Thus, single-file rotary instruments performed better with the less extrusion of debris when compared to multifile rotary systems.

Tracer dynamics in the active random average process

We investigate the dynamics of tracer particles in the random average process (RAP), a single-file system in one dimension. In addition to the position, every particle possesses an internal spin variable σ(t) that can alternate between two values, ±1, at a constant rate γ. Physically, the value of σ(t) dictates the direction of motion of the corresponding particle and, for finite γ, every particle performs non-Markovian active dynamics. Herein, we study the effect of this non-Markovian behavior in the fluctuations and correlations of the positions of tracer particles. We analytically show that the variance of the position of a tagged particle grows sub-diffusively as ∼ζqt at large times for the quenched uniform initial conditions. While this sub-diffusive growth is identical to that of the Markovian/non-persistent RAP, the coefficient ζq is rather different and bears the signature of the persistent motion of active particles through higher-point correlations (unlike in the Markovian case). Similarly, for the annealed (steady-state) initial conditions, we find that the variance scales as ∼ζat at large times, with the coefficient ζa once again different from the non-persistent case. Although both ζ q and ζa individually depart from their Markovian counterparts, their ratio ζa/ζq is still equal to 2 , a condition observed for other diffusive single-file systems. This condition turns out to be true even in the strongly active regimes, as corroborated by extensive simulations and calculations. Finally, we study the correlation between the positions of two tagged particles in both quenched uniform and annealed initial conditions. We verify all our analytical results using extensive numerical simulations.

Dentinal Crack Formation and Quality of Obturation Using Two Single File Systems and Two Obturation Techniques: A micro-CT Study.

Background and objectives: Root canal preparation following obturation with rotary instruments and different obturation techniques may lead to formation of microcracks in the root canal wall, void and gaps between the canal wall and obturation material. Aim: This study aimed to evaluate dentinal microcracks and voids formation after using two different files TruNatomy (TRN) and Genius (GN) and two obturation techniques Single Cone (SC) and GuttaCore (GC) using Microcomputed tomography scan (micro-CT). Methods: 40 extracted mandibular premolars were decoronated, leaving 13mm roots. The roots were randomly divided into two main groups TRN and GN ((n=20)) according to instrumentation, afterwards each group subdivided into two subgroups ((n=10)) according to obturation techniques. The root canals instrumented with TRN and GN file and obturated with Single Cone (SC) and GuttaCore (GC) obturation techniques. AH Plus sealer was used in all groups. The specimens were scanned with Micro-CT before and after root canal preparation and after obturation. subsequently, all pre-and postoperative cross-sectional images of the roots were screened to identify the presence of dentinal defects. Furthermore, the percentage of voids volume calculated. Data were analyzed statistically to determine difference between groups, the level of statistical significance was at p &lt; 0.05. Results: GN revealed the least number of microcracks. There were no significant differences between groups in the incidence of dentinal microcracks. The highest percentage of filling material was observed in GC groups. There were significant differences between the obturation groups in the number of voids present after obturation (P &lt; 0.001). Conclusion: The instrumentation of root canals induces dentinal microcracks. Obturation have no effect on the formation of cracks. None of the root canal filling procedures yield fillings that are void-free. Keywords: Dentinal crack, Voids, Micro CT, Guttacore, Singlecone, TruNatomy, Genius.

Comparative evaluation of the effects of different torque settings on dentinal crack formation using single- and multi-file system: An in vitro study.

To improve efficiency, biomechanical preparation in root canal treatment is shifting from manual SS to nickel-titanium (NiTi) rotary devices. While multi-file NiTi systems entail crack and fracture issues, modern single-file systems address these concerns. The aim of this study was to evaluate and compare the effects of different torque settings on dentinal crack formation using single-file systems (SFS) (One Curve [OC]) and multi-file systems (ProTaper Next [PTN]) at different levels of the tooth. The study was conducted on 45 freshly extracted human mandibular premolars divided into groups: OC at minimal and maximal torque, PTN at minimal and maximal torque, and a control group. After canal preparation, teeth were horizontally sectioned at 3, 6, and 9 mm from the apex, and then examined for cracks using a stereomicroscope. This was analyzed using Chi-square test. PTN group: Highest crack rates at the middle (55.6%) and apical (77.8%) thirds with maximum torque; OC group: Highest rates at the middle (22.2%) with minimal torque and apical (11.1%) with maximum torque. Maximal torque settings had more incidence of cracks compared to minimal torque settings. It can be stated that SFS (OC) produced less cracks compared to multi-file system (PTN) at both minimal and maximal torque settings.

Effect of Movement Kinematics and Heat-Treated Alloys on the Apical Extrusion of Debris: An In Vitro Study

Background: Apically extruded debris can be affected by some features of the file systems such as kinematics or metallurgic properties. Aims: This in vitro study aimed to evaluate the effect of movement kinematics (reciprocation or rotation) and heat-treated alloys (C.Wire) on the amount of debris extrusion. Methods: Seventy-two mesiobuccal root canals were assigned into three experimental groups related to the single-file system used (n = 24): two rotational; One Shape (Conventional Ni-Ti), One Curve (C.Wire), and one reciprocating; and One Reci (C.Wire). The file systems were used according to the advisable speed and torque according to the manufacturers’ suggestion. The weight of debris was calculated by subtracting the preweights from postweights of Eppendorf tubes. Kruskall–Wallis and Mann–Whitney U tests were used to analyze the data (P = 0.05). Results: One Shape produced the greatest amount of extruded debris compared with One Curve (P &lt; 0.001) and One Reci (P &lt; 0.001), respectively. No statistical difference was found between One Curve and One Reci concerning amount of apical debris extrusion (P = 0.489). Conclusion: Metallurgical properties of files may affect apical debris extrusion. Alloy type is an important factor in the amount of debris extrusion. File kinematics does not affect apical debris extrusion.

Effects of different irrigation activation methods on root canal treatment of primary teeth.

There is currently a lack of research on the application of newly developed irrigation techniques in root canal treatment of primary teeth. This study aimed to evaluate the effects of various irrigation activation techniques on two key parameters: apical debris extrusion (ADE) and dentinal tubule penetration depth (DTPD) of the root canal filling material. A total of 96 primary mandibular second molars were randomly divided into 4 groups: Group 1-Conventional Needle Irrigation (CNI), Group 2-XP-Endo Finisher (XPF), Group 3-EndoActivator (EA), and Group 4-Passive Ultrasonic Irrigation (PUI). In all groups, the One Reci single-file system was used for root canal preparation. For ADE measurement, each group was rinsed with distilled water. For DTPD assessment, sodium hypochlorite (NaOCl) was applied. ADE quantification was performed by collecting debris in pre-weighed Eppendorf tubes. A combination of fluorescent dye and root canal filling material (DiaPex Plus) was used for root canal filling. In order to examine DTPD, horizontal cross-sections of the coronal and apical regions of the teeth were taken with a thickness of 1 mm. The maximum and mean DTPD was examined by confocal laser scanning microscopy. Data were analyzed using the Kruskal-Wallis, One-way ANOVA, and Mann-Whitney U tests (p = 0.05). As a result, PUI had the highest mean ADE and CNI had the lowest mean ADE, while CNI had the highest mean DTPD in both the coronal and apical regions, whereas PUI had the lowest mean DTPD in the coronal region, and EA had the lowest mean DTPD in the apical region. There were no statistically significant differences in DTPD and ADE among the four groups. Comparing intragroup maximum DTPD across all groups, it was significantly higher in the coronal region than in the apical region (p < 0.05). ADE and DTPD of root canal filling materials in primary teeth did not differ significantly among CNI, XPF, EA and PUI irrigation activation techniques.

Cryotherapy Treatment Effect on Heat-Treated Nickel-Titanium (NiTi) Rotary Single-File System: An In Vitro Comparative Study by Finite Element Analysis.

Background The use of endodontic files multiple times can cause fatigue in them and can lead to their separation in the root canal. The purpose of this study was to achieve a reduction in cyclic fatigue stress in a newly introduced nickel-titanium (NiTi) rotary single-file system.The study aimed to determine whether cryotherapy could help reduce cyclic fatigue and stress on rotary files after multiple uses during root canal treatment. By utilizing finite element analysis (FEA), the study provided a comprehensive evaluation of how cryotherapy might enhance the performance and longevity of these instruments, ultimately benefiting patients undergoing root canal therapy. Methodology This in vitro comparative studyused scanned plastic teeth with genuine root canal anatomy and FEAto investigate the mechanical response to cyclic fatigue and stress of NiTi rotary file system. The endodontic file (Procodile, Komet) was created through the complex root canal geometries, for which mandibular tooth models were scanned and created by a computer software (IDEAS11 NX; UGSiPlano, TX). The total sample size was 34, divided into two groups, with each group comprising 17 participants (n = 17).The results were analyzed by analysis of variance (ANOVA) test. Results The results revealed that the p-values were more than 0.525, indicating no significant reduction in cyclic fatigue when the NiTi rotary single-file system (Procodile, Komet) was treated with cryotherapy (eight cycles). However, stress reduction was observed in the NiTi rotary single-file system when it was treated with cryotherapy. Conclusion This in vitro comparative study concluded that cryotherapy helps to reduce the stress of NiTi rotary single-file system. Nonetheless, more research is needed to understand the clinical significance of the findings of the current in vitro study.

Types of surface defects and incidence of fracture after root canal preparation using different single file systems at different torque settings using SEM (In vitro study)

Types of surface defects and incidence of fracture after root canal preparation using different single file systems at different torque settings using SEM (In vitro study)

Exact fluctuation and long-range correlations in a single-file model under resetting.

Resetting is a renewal mechanism in which a process is intermittently repeated after a random or fixed time. This simple act of stop and repeat profoundly influences the behavior of a system as exemplified by the emergence of nonequilibrium properties and expedition of search processes. Herein we explore the ramifications of stochastic resetting in the context of a single-file system called random average process (RAP) in one dimension. In particular, we focus on the dynamics of tracer particles and analytically compute the variance, equal time correlation, autocorrelation, and unequal time correlation between the positions of different tracer particles. Our study unveils that resetting gives rise to rather different behaviors depending on whether the particles move symmetrically or asymmetrically. For the asymmetric case, the system for instance exhibits a long-range correlation which is not seen in absence of the resetting. Similarly, in contrast to the reset-free RAP, the variance shows distinct scalings for symmetric and asymmetric cases. While for the symmetric case, it decays (towards its steady value) as ∼e^{-rt}/sqrt[t], we find ∼te^{-rt} decay for the asymmetric case (r being the resetting rate). Finally, we examine the autocorrelation and unequal time correlation in the steady state and demonstrate that they obey interesting scaling forms at late times. All our analytical results are substantiated by extensive numerical simulations.

Postendodontic Pain Using Single File System with Different Irrigation Protocols in Single-visit Root Canal Treatment: A Randomized Control Trial.

To evaluate the intensity of postendodontic pain (PEP) using final irrigation with side-vented needle (SV), EndoActivator (EA), and Ultra X (UX) in single-visit endodontics (SVE) with F-One rotary files. A total 150 patients indicated for endodontic treatment were selected. Single-visit endodontics treatment was performed under local anesthesia. For the final irrigation protocol, they were divided into three groups: group I (SV), group II (EA), and group III (UX). The severity of PEP was assessed using visual analogue scale (VAS) score after 6, 12, 24, and 48 hours. Analgesics taken by patients, for pain, were also recorded. Finally, the data were tabulated and statistically analyzed using SPSS 20.0 software at a level of significance being 0.05. Postendodontic pain was less in group III (UX) and group II (EA) compared with group I (SV) at 6 and 12 hours, which is statistically significant (p < 0.05). There was no statistically significant difference found after 24 hours and 48 hours. The intensity of PEP was minimum in patients treated with EndoActivator and ultrasonic along with single rotary file systems. The incidence of analgesic intake was similar in all three groups. How to cite this article: Kathiria NV, Attur K, Bagda KM, et al. Postendodontic Pain Using Single File System with Different Irrigation Protocols in Single-visit Root Canal Treatment: A Randomized Control Trial. J Contemp Dent Pract 2024;25(2):180-185.

Universal anomalous fluctuations in charged single-file systems

Introducing a general class of one-dimensional single-file systems (meaning that particle crossings are prohibited) of interacting hardcore particles with internal degrees of freedom (called charge), we exhibit a dynamical universality reflected in anomalous statistical properties of macroscopic fluctuating observables such as charge transfer. We find that stringent dynamical constraints lead to universal anomalous statistics of cumulative charge currents manifested both on the timescale characteristic of typical fluctuations and also in the rate function describing rare events. By computing the full counting statistics of net transferred charge between two extended subsystems, we establish a number of unorthodox dynamical properties in an analytic fashion. Most prominently, typical fluctuations in equilibrium are governed by a universal distribution that markedly deviates from the expected Gaussian statistics, whereas large fluctuations are described by an exotic large-deviation rate function featuring an exceptional triple critical point. Far from equilibrium, competition between dynamical phases leads to dynamical phase transitions of first and second order and spontaneous breaking of fluctuation symmetry of the univariate charge large-deviation function. The rich phenomenology of the outlined dynamical universality is exemplified on an exactly solvable classical cellular automaton of charged hardcore particles. We determine the dynamical phase diagram in the framework of Lee–Yang's theory of phase transitions and exhibit a hyper-dimensional diagram of distinct dynamical regimes. Our findings lead us to conclude that the conventional classification of dynamical universality classes based on the algebraic dynamical exponents and asymptotic scaling functions that characterize hydrodynamic relaxation of the dynamical structure factor is incomplete and calls for refinement. Published by the American Physical Society 2024

Anomalous phase diagram of the elastic interface with nonlocal hydrodynamic interactions in the presence of quenched disorder.

We investigate the influence of quenched disorder on the steady states of driven systems of the elastic interface with nonlocal hydrodynamic interactions. The generalized elastic model (GEM), which has been used to characterize numerous physical systems such as polymers, membranes, single-file systems, rough interfaces, and fluctuating surfaces, is a standard approach to studying the dynamics of elastic interfaces with nonlocal hydrodynamic interactions. The criticality and phase transition of the quenched generalized elastic model are investigated numerically and the results are presented in a phase diagram spanned by two tuning parameters. We demonstrate that in the one-dimensional disordered driven GEM, three qualitatively different behavior regimes are possible with a proper specification of the order parameter (mean velocity) for this system. In the vanishing order parameter regime, the steady-state order parameter approaches zero in the thermodynamic limit. A system with a nonzero mean velocity can be in either the continuous regime, which is characterized by a second-order phase transition, or the discontinuous regime, which is characterized by a first-order phase transition. The focus of this research is to investigate the critical scaling features near the pinning-depinning threshold. The behavior of the quenched generalized elastic model at the critical depinning force is explored. Near the depinning threshold, the critical exponent is obtained numerically.

Impact of root canal preparation using two single-file systems on the intra-radicular microbiome of teeth with primary apical periodontitis

ObjectivesThis study aimed to describe the effects of two single-file systems on the diversity of the endodontic microbiome of teeth with primary asymptomatic apical periodontitis.Materials and methodsThe root canals from single-rooted teeth with apical periodontitis were prepared using either the Reciproc Blue (RB) or the XP-endo Shaper (XPS) instrument system. The latter was followed by a supplementary step with the XP-endo Finisher (XPF) instrument. For irrigation, 5.25% sodium hypochlorite was used. Root canal samples were taken at the baseline (S1), after preparation (S2), and after the supplementary step (S3). DNA was extracted and subjected to high-throughput sequencing using the MiSeq Illumina platform.ResultsSamples from 10 teeth from the RB and 7 from the XPS group were subjected to DNA sequencing. Initial samples differed significantly from post-preparation samples in bacterial diversity, with no significant difference when comparing the two instrument systems. The most dominant phyla in S2 were Bacteroidetes, Proteobacteria, Firmicutes, Fusobacteria, and Actinobacteria. The same phyla were found to dominate baseline samples and samples taken after using XPF, but with differences in the ranking of the most dominant ones. At the genus level, the most dominant genera identified after RB instrumentation were Bacteroidaceae [G-1], Fusobacterium, and Staphylococcus, while the most dominant genera after XPS instrumentation were Fusobacterium and Porphyromonas. These genera were also dominant in the initial samples.ConclusionsBoth treatment protocols had measurable effects on the root canal microbial diversity, with no significant differences between them. Most of the dominant taxa involved in the primary infection and probably in the aetiology of apical periodontitis were eliminated or substantially reduced.Clinical relevanceThe most dominant taxa that persisted after instrumentation were Fusobacterium, Porphyromonas, Staphylococcus, and Bacteroidaceae [G-1].