Reciprocal System Research Articles

A Comparative Evaluation of the Apically Extruded Debris from Root Canals Prepared by R-Motion NiTi File System.

Apically extruded debris (AED) is an inherent concern during root canal treatment for both endodontists and general practitioners. The present study investigates the AED of the novel R-Motion single-file reciprocating system compared to standard single reciprocating and multifile rotary systems. Fifty-six moderately curved palatal roots of upper maxillary first molars were selected for the present study. The samples were then divided randomly into four groups (n = 14)- Group I: R-motion (RM), Group II: WaveOne Gold (WOG), Group III: ProTaper Next (PTN), and Group IV: HyFlex EDM (HFEDM). The researcher has modified Myers and Montgomery's method to simulate human body temperature. Vials were used to collect debris and weighted using a 0.00001 sensitive balance before and after instrumentation. The instrumentation of all experimented groups was done at 37°C, terminated at master apical file #25. An auto syringe with a side vented needle was used to deliver 8 ml of deionized water for irrigation of each sample during preparation. Vials were stored in a dry sealed desiccator which contained CaSO4 crystals, for 24 hr before weighing. The weight of the collected debris was obtained by subtracting the preinstrumentation weight from the postinstrumentation weight for each vial. The Kruskal-Wallis and Mann-Whitney U tests were performed to analyse the statistical difference in the amount of debris between the tested groups at a 0.05 significance level. The RM system produced less debris extrusion than all tested groups, with a significant difference between the former and the WOG and the PTN systems. However, WOG, PTN, and HFEDM showed no statistically significant difference in the amount of AED. All tested groups produced apical debris in different amounts. The RM produced substantially less AED than WOG and PTN. Meanwhile, WOG, PTN, and HFEDM caused a comparable amount of AED.

An Examination of the Impact of Blue Heat Treatment on the Forced Caused by the Vertical Motion of Endodontic Files

Objective: To assess the vertical forces produced during canal shaping by the Reciproc Blue (RB) and Reciproc (R) systems. Place and Duration: In the Operative Dentistry Department, Altamash Institute of Dental Medicine Karachi for one-year duration from January 2022 to December 2022. Methods: A total of 32 maxillary premolar teeth were selected, each with two distinct constricted and straight canals. Every tooth was positioned in a standing position on a platform attached to a force analysing device after access cavity preparation (M5-20 Advanced Digital Force Gauge; Mark-10 Corporation, NY, USA). Until the K file size was up to 15, the glide route was prepared manually. Then, using an R25/RB25 file, all of the groups' canals were completely shaped (0.08 taper, size 25). The canal was shaped with a mild and steady pressure on the file that produced a gradual, 2 mm amplitude "in-and-out" movement. It took three attempts for the file to successfully reach the WL. The canal was irrigated and recapitulated with sodium hypochlorite (1%) solution following each insertion. The Student's t-test was used to analyze the shaping time. The Mann Whitney test was applied to analyse the upward and inward peak forces. With a 95% level of confidence, SPSS software was used for all statistical analyses. Results: A single file was inserted into each root canal successfully three times for shaping till the WL achieved. With each additional file insertion, the overall real-time force increased in each group grew. The R group displayed lower peak forces in comparison to the RB group in the 3 insertions, and both groups inward peak forces varied from 1.76 to 8.64 N. (P<0.05). Complete canal shaping of the RB and R systems took an average of 24.30±3.98 s and 21.91±3.56s, respectively (P>0.05). During canal shaping in this experiment, no file fracture occurred. Conclusion: The forces generated during canal shaping were influenced by the blue heat treatment. Higher inward peak forces were higher in the RB file than the R file. Keywords: Root canal preparation, Endodontics, vertical force and shaping time.

First Experience of an Undergraduate Dental Student with a Reciprocating System in Simulated Root Canals—A Pilot Study

Rotary instrumentation has been proposed in undergraduate teaching. The aim of this study was to evaluate student’s performance, through the obturation quality and treatment time, in a sequential range of L-simulated root canals. A senior undergraduate dental student sequentially prepared randomly numbered canals from 1 to 40, with the WaveOne Gold glider and primary file, according to the manufacturer instructions. A gutta-percha cone matched with the finishing instrument and epoxy resin-based sealer (AH Plus) was selected for the obturation. Three independent observers evaluated the obturation quality according to both density and length. Active, total instrumentation and obturation times were also measured. Statistical analysis was obtained by Mann–Whitney and Kruskal–Wallis tests with a significance level of p < 0.05. The quality of the obturation was independent of the number of prepared canals with adequate length and density in 87.5% of the prepared canals. Both active and total instrumentation, as well as obturation times, reduced significantly as the number of the prepared canals by the student increased (p ˂ 0.05). The use of WaveOne Gold instrumentation and matched cone obturation by an inexperienced operator provided an adequate obturation quality in most of the curved simulated canals. The working time was significantly reduced through a short learning curve.

Modeling of the Phase Assemblage of the LiF–Li2CrO4–LiRbCrO4–LiKCrO4 Stable Tetrahedron of the Li+, K+, Rb+||F–, Quaternary Reciprocal System

Here, phase equilibria in a quaternary reciprocal system comprised of fluorides and chromates of lithium, potassium, and rubidium was studied. The phase assemblage of the system was partitioned to stable simplices. The Li–Li2CrO4–LiRbCrO4–LiKCrO4 stable tetrahedron was selected as the subject matter of this study due to its undoubted scientific importance. The analysis of the boundary elements predicted, and the DTA experimental study of phase equilibria in the system proved, that monovariant phase equilibrium L ⇄ LiF + α-Li2CrO4 + (LiKxRb1 – xCrO4)ss is realized in the system, described by line Е 397–Е 400; the characteristics of the minimum point of this monovariant equilibrium (Min◻ 367) were elucidated. The mass balance of the phase reaction for this point is presented. A 3D model of the phase assemblage of the system was designed based on experimental data. The system preserves the continuity of (LiKxRb1 – xCrO4)ss solid solutions. The mixture whose composition corresponds to point Min◻ 367 has a relatively low melting temperature and can serve as a material for new fusible electrolytes in chemical current sources; it can also be of interest as an electrolytic bath for recovery of metals from melts.

Racial Equality and Anticolonial Solidarity: Anténor Firmin’s Global Haitian Liberalism

This article recovers Anténor Firmin’s contribution to anticolonial political thought by excavating his liberal worldmaking project of global racial equality and anticolonial solidarity. I assess Firmin’s contrast between “true” and “false” liberalism in Haiti, reconstructing his understanding of true Haitian liberalism as committed to the core ideas of historical progress, national regeneration, and rehabilitation of the Black race globally. I contextualize his Equality of the Human Races in metropolitan Paris during his first exile, arguing that his critique of anthropological racism should be seen as integral to his commitment to Haitian liberalism. I then situate his discussion of what he called “European Solidarity” in wider legitimating languages of French colonialism. This recovers Firmin’s neglected critique of colonialism as a reciprocal system of economic exploitation and discursive domination, and his attempt to rescue the universal ideal of solidarity from its truncated expression in languages of racial inequality and practices of colonization.

Study on the process of producing sodium percarbonate

To increase the washing efficiency and more completely remove stained impurities, chemical bleaches are introduced into the composition of SD (synthetic detergents), the most common of which are peroxide salts - sodium peroxocarbonate (percarbonate) and sodium peroxoborate (perborate).The theoretical substantiation of the process of interaction of sodium carbonate and hydrogen peroxide in the three-component reciprocal system Na2CO3-H2O2-H2O by the visual-polythermal and isothermal method at 10 and 30°C is carried out. The formation of new compounds of the compositions: Na2CO3•1,5H2O2, Na2CO3•H2O•2H2O2 and Na2CO3•2H2O2 was established, for which the concentration limits of existence were determined. New compounds are identified by chemical and physico-chemical analysis methods.

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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.

Radicular Intracanal Splitting Forces and Cutting Efficiency of NiTi Rotary Versus Reciprocating Systems: A Comparative In Vitro Study

This study aimed to compare the intracanal lateral force and cutting efficiency associated with two engine-driven nickel-titanium (NiTi) systems during root canal shaping. Bovine single-rooted teeth models were assembled to a custom-made splitting force measuring platform while being endodontically treated with rotary (ProTaper Gold [PTG]) or reciprocal systems (WaveOne Gold [WOG]) by two clinicians. The cutting efficiency test was run for each group by a free-falling endomotor on dentin discs for 3 min. The resulting force, files, and stroke force peaks were recorded. Data were analyzed by the Shapiro-Wilk test and ANOVA. Statistical significance was set at alpha = 0.05. Intracanal lateral forces (p < 0.01), cutting efficiency (p < 0.01), and time efficiency (p < 0.01) were significantly different between the NiTi groups. The maximum lateral splitting force was detected using the PTG shaping full-length file (S1) and during the WOG final stroke. Thus, caution is advised when reciprocating single-file systems approach the apical third or when using a large taper and wide-diameter rotatory instruments. The WOG had significantly less maximum horizontal splitting force and significantly greater cutting efficiency but less time efficiency than the PTG system.

Family's roles as a welfare pillar: The case of older persons living in extreme poverty in Bangladesh

SummaryMotivationMany mainstream welfare theories developed by social scientists and applied by economists and policy‐makers underestimate families' roles in providing welfare to citizens. This is surprising given that the family constitutes one of the main welfare pillars across typologies of the welfare state.PurposeThis article seeks to explore the role of the family as a welfare pillar with an ageing perspective. We aimed to test whether the family serves as a space for negotiations to improve wellbeing and achieve security in the absence of effective formal mechanismsMethods and approachApplying the framework of “informal security regimes,” this article draws on 37 life‐history interviews collected from older persons living in extreme poverty in Bangladesh. Recurring themes are identified and analysed to explore the relationship between family and wellbeing/security.FindingsWe find that family relationships are often central in the pursuit of security. This shows how welfare delivery in low and middle‐income countries (LMICs), in this case Bangladesh, is deeply rooted in reciprocal family systems where all members actively fulfil moral and material expectations. Pursuing this collective goal can take different forms relative to each member's physical and mental capacity, position, gender, and age. Building on the empirical evidence, we propose the concept of “relational security” as a crucial marker and shaper of wellbeing.Policy implicationsTo be effective, welfare policies need to better consider how the conception and experiences of wellbeing and security, especially for the older persons living in extreme poverty, are deeply embedded within the complex functioning of the relationships that can shape welfare outcomes in different directions.

Aksi Irasional dan Keseimbangan Sosial dalam Perubahan Sosial akibat Penggunaan Mesin Pertanian Modern pada Pengelolaan Sawah

The inclusion of modern agricultural machinery, combine harvesters, in a village can have two social impacts: (1) the loss of a culture of mutual cooperation with a system of reciprocity between landowners and farm workers, and (2) a large loss of employment opportunities for farm workers in managing agricultural land in their villages. This can certainly make the social balance in the village disturbed, even so in Permata Village this balance is maintained. This social balance was researched using Vilfredo Pareto's individual action analysis framework and using qualitative approaches and case study methods. Social facts are moulders of individual actions, and rational actions exist only within economic facts, so a number of problems that are not resolved by economic means require consideration of irrational factors. The informant's statements regarding the actions they performed were analyzed to be categorized as irrational, which was then discussed with the concept of residue and derivation from Pareto. This study succeeded in explaining that there are four main factors of irrational actions that maintain social balance in the village, these four factors are reduced to coincidence factors and factors of systematic and appropriate interpretation and way of responding by the village government elite.

Efficiency of the new reciprocating and rotary systems with or without ultrasonics in removing root-canals filling with calcium silicate-based sealer (MTA)

BackgroundTo compare the efficiency of endodontic rotary and reciprocating systems in removing calcium silicate-sealer based fillings and to investigate the impact of passive ultrasonic irrigation (PUI) on their efficiency.Materials and methods160 root-canals were instrumented, filled with gutta-percha and calcium silicate based-sealer and divided into 10 equal groups. Five groups in which the reciprocating systems (WaveOne-Gold, Reciproc-Blue and R-Motion) and rotary systems (Fanta-AF-One and Tango-Endo) were used to remove root-canals’ fillings. In the other five groups the fillings were removed by the same systems then additionally with PUI. The times to complete retreatments procedures were recorded. Micro-computed tomography’s analysis of the root-canals fillings’ volume before and after retreatments was used to determine the remaining filling materials (RFMs) volumes.ResultsThe RFMs after using rotary systems (10.1%) was greater than after using reciprocating systems (3.8%) (P < 0.001). The RFMs after using WOG (2%) and RB systems (2.6%) were less than those in the RM (6.8%), TE (9.5%) and FAFO (10.7%) systems [P < 0.05]. The times required to remove the filling materials using the TE (3.7 min), FAFO (4.1 min) and RM (4.1 min) systems were shorter than those required by the RB (5.4 min) and WOG (4.9 min) systems [P < 0.05]. Using PUI resulted in less RFMs (1.44%) when compared to using only rotary or reciprocating systems (6.27%) [P < 0.001].ConclusionsEndodontic reciprocation systems were more effective, but needed longer times than rotary systems in removing calcium silicate based- sealers fillings. The PUI significantly improved removal of the root-canals’ filling materials.Clinical relevance: Reciprocating systems and PUI are recommended whenever root-canals retreatment is considered regardless of using calcium silicate-based sealers.

‘A whole society, with its own economic system’: the reciprocal and capitalist configurations of American DIY music scenes

ABSTRACT In this article, I examine the alternative economics of reciprocity in American DIY (do-it-yourself) culture. Through long term ethnographic study of local and translocal DIY scenes, including shows, spaces, and touring practices, I reveal a plethora of reciprocal musical and extra-musical activities that enable the creation of alternative DIY worlds. Yet I also highlight how these alternative economic systems of reciprocity coexist with capitalist ones. Drawing on Arjun Appadurai’s theories of value and commodity (1986), alongside other authors who examine the co-existence of different economic systems, I chart how DIY practitioners tactically navigate the boundaries between these reciprocal and capitalist economic systems and worlds. These socio-economic relations, I argue, also shape DIY sounds and aesthetics, as well as contribute to distinct musical values, discourses and practices.

An Automatic Threshold Selection Using ALO for Healthcare Duplicate Record Detection with Reciprocal Neuro-Fuzzy Inference System

ESystems based on EHRs (Electronic health records) have been in use for many years and their amplified realizations have been felt recently. They still have been pioneering collections of massive volumes of health data. Duplicate detections involve discovering records referring to the same practical components, indicating tasks, which are generally dependent on several input parameters that experts yield. Record linkage specifies the issue of finding identical records across various data sources. The similarity existing between two records is characterized based on domain-based similarity functions over different features. De-duplication of one dataset or the linkage of multiple data sets has become a highly significant operation in the data processing stages of different data mining programmes. The objective is to match all the records associated with the same entity. Various measures have been in use for representing the quality and complexity about data linkage algorithms, and many other novel metrics have been introduced. An outline of the problem existing in the measurement of data linkage and de-duplication quality and complexity is presented. This article focuses on the reprocessing of health data that is horizontally divided among data custodians, with the purpose of custodians giving similar features to sets of patients. The first step in this technique is about an automatic selection of training examples with superior quality from the compared record pairs and the second step involves training the reciprocal neuro-fuzzy inference system (RANFIS) classifier. Using the Optimal Threshold classifier, it is presumed that there is information about the original match status for all compared record pairs (i.e., Ant Lion Optimization), and therefore an optimal threshold can be computed based on the respective RANFIS. Febrl, Clinical Decision (CD), and Cork Open Research Archive (CORA) data repository help analyze the proposed method with evaluated benchmarks with current techniques.

A comparative evaluation of dentinal defects after root canal preparation with different rotary and reciprocal systems

Aim: This study aimed to compare dentinal defects after root canal preparation with various reciprocating and continuous rotary files.Methods: 90 extracted human mandibular incisor teeth were used. 15 teeth left unprepared and the remaning teeth were randomly divided into 5 experimental groups (n=15). Root canals were prepared with WaveOne (Dentsply Maillefer, Ballaigues, Switzerland), WaveOne Gold (Dentsply Maillefer, Ballaigues, Switzerland), Hyflex EDM OneFile (Coltene/Whaledent, Altstätten, Switzerland), ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland), and ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland) rotary files. Then roots were sectioned at 3, 6 and 9 mm from the apex and evaluated with a stereomicroscope. Statistical analysis was performed with chi-square and Fischer’s Exact test. The significance level was set at 5%.Results: No defects were observed in the unprepared control group. Dentin defect were observed in all the experimental groups, especially in the apical region (3 mm). WaveOne and Hyflex EDM showed more dentinal defects than the control group (p0.05). WaveOne caused significantly more dentinal defects than the ProTaper Universal, ProTaper Next, and WaveOne Gold groups (p

Graph Fusion in Reciprocal Recommender Systems

Unlike traditional user-item recommendation tasks (e.g., movie or consumer-product recommendation), reciprocal recommender systems (RRSs) (e.g., online dating services and job-recruitment sites) must consider the interests of both two users. Pair matching prediction can improve the efficiency with which RRSs match potential partners. Graph Neural Networks (GNNs) are powerful models for learning representations of attributed graphs and information circulation between nodes. GNNs greatly facilitate link prediction in the area of user-item recommender systems but have not been extensively applied to RRS. In this study, we present a novel method for pair matching prediction that learns the reciprocal information circulation between users: not only side information about them but also structural information about their behavior histories. In contrast to earlier RRSs, which focus on response prediction, ours predicts both send and reply signals. Moreover, we introduce negative sample mining to explore the effect of different types of multiple samples on recommendation accuracy in real applications. Testing our method on data provided by an online dating service, we achieved an AUC of 73.15% (an absolute improvement of over 3.20% point above baseline) and an AP of 26.01% (an absolute improvement of over 2.79%) on send prediction; an AUC of 68.95% (an absolute improvement of over 1.74%) and an AP of 23.02% (an absolute improvement of over 0.70%) on reply prediction; an AUC of 71.26% (over 4.35% point absolute improvement) and an AP of 23.95% (over 0.30% point absolute improvement) on fusion reciprocal prediction.

Micro- CT evaluation of sealers removal by reciprocal instrumentation followed by continuous ultrasonic irrigation in teeth with oval root canals.

The ability of the Reciproc system (R40) followed by continuous ultrasonic irrigation (CUI) to remove filling material from oval root canals of mandibular premolars filled with gutta-percha and AH Plus or Bio-C Sealer was evaluated by microtomography (micro-CT). The straight and oval root canals of 42 mandibular premolars were prepared with the ProDesign R 35.05 reciprocal file and randomly divided into two groups according to the material used to fill the canals (n=21): Group AH - Master Cone and AH Plus; Group BC - Master Cone and Bio-C Sealer. After filling and provisional sealing, the teeth were stored at 100% relative humidity and a temperature of 37°C for 30 days. The filling material was then removed with an R40 file. The material was considered completely removed when the R40 file reached the working length (WL), and no remaining filling material was visible on the canal walls. CUI was then performed. The teeth were scanned by micro- CT before and after removal of the filling material. The remaining filling material was measured in mm in the last apical 5 mm. The data were analyzed with the nonparametric Friedman test and subsequently with the Dunn test. The Mann-Whitney U test was also performed. Statistical significance was accepted at the 5% level. After instrumentation with the Reciproc R40, the volume of residual filling material was significantly greater in the BC group than in the AH group (P = 0.035). After CUI, there was no difference in the volume of residual material between the two groups (P = 0.705). Bio-C sealer was more difficult to remove with the Reciproc file than AH Plus. CUI improved the removal of residual filling material regardless of sealer type. However, no technique was able to completely clear the canals of filling material. Key words:Bioceramic cement, CUI, micro-CT, reciproc, retreatment.

A Four-Component Reciprocal System of Tungstate and Sulfates of Lithium, Sodium, and Lead

A Four-Component Reciprocal System of Tungstate and Sulfates of Lithium, Sodium, and Lead

Thermodynamic properties of KCaCl(NO3)2 compound and influence of kinetic effects

The thermodynamic properties of the intermediate compound KCaCl(NO3)2 are important for the thermochemical description of the KCl–CaCl2–KNO3–Ca(NO3)2 reciprocal system, for its utilization as a phase change material or heat transfer fluid in thermal energy storage. The formation of KCaCl(NO3)2 as intermediate compound in this reciprocal system was confirmed by X-Ray diffraction analysis. Aside from the main phase of KCaCl(NO3)2, other crystalline phases were also identified. Kinetic effects were observed during the study of this compound. For example, the enthalpy of fusion of the 50KCl–50Ca(NO3)2 mixture depends on the cooling rate of the previous cycle. The samples, which crystallized with 10 K/min, show higher enthalpy of fusion (22.4 kJ/mol) compared to samples cooled with 0.5 K/min - 16.3 kJ/mol. This effect is related to the different ratio of crystallized phases (KCaCl(NO3)2, KCaCl3, Ca(NO3)2 and various Potassium Calcium nitrates) in this mixture. The heat capacity and enthalpy increment of the KCaCl(NO3)2 compound in solid and liquid phases are determined with two different DSC instruments. The selected value of the fusion enthalpy for KCaCl(NO3)2 compound is 22.4 ± 1.2 kJ/mol, which was obtained after fast (10 K/min) cooling. The comparison of the experimental results with calculated values based on Neumann-Kopp rule confirms the reliability of the obtained data.

Erratum to: Phase Equilibria in the LiF–LiCl–Li2CrO4–KCl Stable Tetrahedron of the Li,K||F,Cl,CrO4 Reciprocal Four-Component Systems

Erratum to: Phase Equilibria in the LiF–LiCl–Li2CrO4–KCl Stable Tetrahedron of the Li,K||F,Cl,CrO4 Reciprocal Four-Component Systems