Evaluation of the Smear Layer Removal Ability of Various Rotary Files with/without Chemical Agents on Primary Teeth: An In Vitro Study.

AIM: The aim of the current study was to assess the cleaning and smear layer removal efficacy of two different rotary files with or without chemical agents on primary teeth. MATERIALS AND METHODS: For the study, 90 extracted primary maxillary incisors without internal or external resorption and with at least two-thirds of complete roots were chosen. Then, based on the kind of instruments used to clean and shape the canals, they were randomly assigned to three experimental groups, each consisting of 30 teeth. Group-I: The canal was instrumented manually with K-files, Group-II: The canal was instrumented with Kedo-S files, Group-III: The canal was instrumented with Kedo-SG Blue files. After the canals were finally instrumented, 2 mL of QMixTM solution was used to irrigate 15 samples from each group. The samples were subsequently allowed to remain in the canals for 90 seconds in order to eliminate the smear layer. After that a stereomicroscope was used to assess the cleaning effectiveness. RESULTS: With irrigant solution, the highest mean value was found in manual K-files (2.86 ± 0.34), followed by Kedo-S files group (1.34 ± 0.26) and Kedo-SG Blue files (1.28 ± 0.18). Without irrigant solution, the highest mean value was found in manual K-files (2.92 ± 0.22) followed by Kedo-S files group (1.44 ± 0.18) and Kedo-SG Blue files (1.36 ± 0.14). There was a statistically significant difference found at all the three levels. CONCLUSION: On conclusion, the current study's findings demonstrated that irrigation solution was significantly more effective in cleaning and removing smear layers from pediatric rotary files than manual K-files. CLINICAL SIGNIFICANCE: The effectiveness of endodontic therapy depends on a successful chemomechanical preparation. The canals are instrumented using either hand files or rotary instruments; there are several irrigation and instrumentation techniques. In order to completely sterilize the canals, chemical agents are utilized for irrigation during instrumentation. Due to their numerous biological, antibacterial, anti-inflammatory, and antioxidant qualities, many natural compounds are also utilized as irrigants. How to cite this article: Abushanan A. Evaluation of the Smear Layer Removal Ability of Various Rotary Files with/without Chemical Agents on Primary Teeth: An In Vitro Study. J Contemp Dent Pract 2024;25(4):354-357.

Post-operative pain after root canal preparation with different apical finishing sizes a triple blinded split mouth clinical trial.

BACKGROUND: This is a triple-blinded, prospective split-mouth clinical trial. It is important to shed light on the effect of different apical preparation sizes regarding postoperative pain within the same patient with the same pulpal histological status. The aim is to compare and evaluate the severity of postoperative pain following apical enlargement with two different sizes after the IBF using the visual analogue scale. METHODS: Fifty "teeth" in 25 patients were assigned into two equal groups (25 per group) using E3 Azure rotary files; Group A was prepared two sizes greater than the Initial binding file (IBF) (the largest K file to bind at the actual working length) mesial canals, which were enlarged to 35#/0.04 and 40#/0.04 for the distal canals. Group B was prepared in three sizes larger than the IBF: 40#/0.04 for mesial canals and 45#/0.04 for the distal canals. On a modified VAS form, patients were questioned to indicate the degree of their pain and assisted in narrating their pain intensity during the following periods: 12, 24, and 72 h, and after a week. VAS data were non-parametric and analyzed using the signed-rank test for intergroup comparisons, Freidman's test, and the Nemenyi post hoc test for intragroup comparisons. The significance level was set at p < 0.05. RESULTS: showed that regardless of measurement time, enlargement of apical preparation was significantly associated with higher pain scores (p < 0.001). Within both groups, there was a significant reduction of measured pain score with time, with values measured after 12 and 24 h being significantly higher than values measured at other intervals (p < 0.001) and with values measured after three days being significantly higher than 1-week value (p < 0.001). CONCLUSION: The size of apical preparation had a significant effect on postoperative pain. TRIAL REGISTRATION NUMBER & DATE: NCT05847738, 08/05/2023.

The influence of different root canal open access shapes on the use of rotary root canal enlargement.

Background/purpose: The success of root canal treatments is influenced by the shape of the access opening and the outcomes of root canal enlargement. The aim of this study was to evaluate the impact of various rotary instruments on the maintenance of the root canal's central alignment post shaping, considering a range of access cavity designs. Materials and methods: Using digital tooth simulation, 4 sets of 12 teeth underwent traditional (TradAC) or conservative (ConsAC) access cavity preparations. Root canals were enlarged with TruNatomy or ProTaper Ultimate rotary instruments. Canal transportation and centering ratio were separately measured. Statistical analysis was performed using JMP trial 17 software. Results: The analysis revealed no significant difference in buccal and lingual canal transportation among different rotary instruments or canal enlargement designs (P > 0.05). TradAC yielded higher centering ratios in MB and ML canals, while ConsAC excelled in the distal canal for the TruNatomy group. Conversely, in the ProTaper Ultimate group, ConsAC demonstrated higher ML canal ratios (P < 0.05). Conclusion: TruNatomy maintained superior canal centering with ConsAC, while ProTaper performed better with TradAC.

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

Context: 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. Aims: 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. Subjects and Methods: 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. Statistical Analysis Used: This was analyzed using Chi-square test. Results: 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. Conclusions: 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.

Extrusion of debris during retreatment using various nickel-titanium files in teeth with simulated lateral root perforation.

PURPOSE: To investigate the influence of various nickel-titanium (Ni-Ti) files on debris extrusion during the retreatment of teeth with simulated lateral root perforation, focusing on root resorption. METHODS: Sixty human mandibular premolar teeth were divided into groups with and without perforation and further subdivided based on the retreatment technique. Lateral root perforations were created in one group (Group 1), while the other group had no perforations (Group 2). Two retreatment techniques were compared: Remover (RE)+One RECI (OR) and ProTaper Universal Retreatment (PTUR)+WaveOne Gold (WOG). The weight of the extruded debris was determined. The time of both retreatment procedures was measured. Statistical analyses were performed using a two-way analysis of variance (ANOVA) test (P < 0.05). RESULTS: Teeth with simulated lateral root perforation exhibited higher extrusion of debris during retreatment. In both groups, RE+OR files led to more extruded debris than PTUR+WOG files. However, this difference was statistically significant in Group 2 (P < 0.001). Compared to PTUR+WOG files, RE+OR files showed a statistically significant longer time to remove obturation material (P < 0.001). CONCLUSION: Perforated teeth exhibited significantly higher debris extrusion. While both file systems demonstrated similar debris extrusion in perforated teeth, the RE+OR files significantly increased debris extrusion in non-perforated teeth compared to the PTUR+WOG files.

Application of municipal solid waste (MSW) char during rotary drum co-composting (RDC) of vegetable waste and its characterization.

Composting, a sustainable method for handling biodegradable waste constituting nearly 50% of municipal solid waste (MSW), can be enhanced by incorporating char produced from MSW pyrolysis. This study investigates the impact of MSW char (0% char-Control, 2.5% char-Trial 1, 5% char-Trial 2) on the physicochemical properties of vegetable waste compost. A thermophilic temperature range of 53.8 °C was detected in Trial 2, 50.8 °C in Trial 1, and 46.8 °C in Control. The pH of the mixes increased at day 20 to 7.5, 7.87, and 8.2 in Control, Trial 1, and Trial 2, respectively. The highest drop of total organic carbon (TOC) and volatile solids in Trial 2 is about 21.18% and 21.02%, respectively. Total Kjeldahl nitrogen (TKN) increased, particularly in Trial 2 (2.35%), while NH4-N concentrations decreased, and phosphorus levels rose notably to 23.48 mg/kg, with 2.49 mg/kg available phosphorus in Trial 2. The C/N was reduced to 10 in Trial 2. Total potassium increase was highest for Trial 1 (6.9 g/kg). Trial 2 had the highest overall macronutrient concentration and correspondingly showed the greatest decrease in volatile solids. Furthermore, Trial 1 demonstrated a reduction in heavy metal concentration in comparison to Control and Trial 2. Consequently, the utilization of MSW char during rotary drum composting enhances the process of composting and significantly improves compost quality, making it a sustainable waste management solution.

The effect of three different primary teeth rotary instrument systems on the amount of apically extruded debris in pulpectomy of primary teeth.

Purpose: The objective of this study is to evaluate the amount of apically extruded debris and working time during root canal treatment with three different primary teeth rotary instrument systems. Materials and methods: A total of 80 extracted primary second molar teeth were randomly divided into four groups (n=20) stratified by the instruments used: AF Baby Rotary, Easyinsmile Baby Rotary, Endoart Pedo Gold, and hand files. The apical extrusion of debris was collected then dried in Eppendorf tubes that were pre-weighed with 10-4 precision micro-balance. The incubation period was set as 14 days at 37°C. The dry weight was procured by deducting the preoperative weight from the postoperative weight. The systems' working time was calculated by chronometer. Mann Whitney U test with Bonferroni correction was used for pairwise comparison following the variance analysis with Kruskal Wallis test. Wilcoxon test was used for intragroup comparison. Results: Although all instruments caused apically extruded debris (p<0.001), there was no statistically significant difference between the groups in debris extrusion. However, the longest working time was found in the manual K files, the Endoart Pedo Gold system had the shortest working time (p<0.001). Conclusion: Our results demonstrate that all instrument systems caused apical extrusion of debris. Furthermore, the rotary instrument systems designed for primary teeth exhibited significantly shorter working time.

Bi-directional context-aware network for the nested named entity recognition.

The Span-based model can effectively capture the complex entity structure in the text, thus becoming the mainstream model for nested named entity recognition (Nested NER) tasks. However, traditional Span-based models decode each entity span independently. They do not consider the semantic connections between spans or the entities' positional information, which limits their performance. To address these issues, we propose a Bi-Directional Context-Aware Network (Bi-DCAN) for the Nested NER. Specifically, we first design a new span-level semantic relation model. Then, the Bi-DCAN is implemented to capture this semantic relationship. Furthermore, we incorporate Rotary Position Embedding into the bi-affine mechanism to capture the relative positional information between the head and tail tokens, enabling the model to more accurately determine the position of each entity. Experimental results show that compared to the latest model Diffusion-NER, our model reduces 20M parameters and increases the F1 scores by 0.24 and 0.09 on the ACE2005 and GENIA datasets respectively, which proves that our model has an excellent ability to recognise nested entities.

Fatigue Strength Assessment of Friction Welds under Consideration of Residual Stress.

A reliable local-fatigue assessment approach for rotary friction-welded components does not yet exist. The scope of this paper is to present test results for the fatigue behaviour of rotary friction-welded solid shafts made of structural steel S355J2G3 (1.0570) and an approach to fatigue assessment considering residual stress. In contrast to fusion-welded joints, components made by rotary friction welding usually contain compressive residual stress near the weld, which can significantly affect the fatigue strength. For this purpose, specimens were welded and characterised, including metallographic micrographs, hardness measurements, and residual stress measurements. The fatigue tests were performed with a constant amplitude loading in tension/compression or torsion with R = -1. All specimens were investigated without machining of the weld flash, either in the as-welded state or after a post-weld stress-relief heat treatment. In addition, the friction welding process and the residual stress formation were analysed using numerical simulation. The characterisation results are integrated into a fatigue assessment approach. Overall, the specimens perform comparatively well in the fatigue tests and the experimentally observed fatigue behaviour is well described using the proposed local approaches.

Preparation and Characterization of Lutein Co-Amorphous Formulation with Enhanced Solubility and Dissolution.

Lutein is an oxygenated fat-soluble carotenoid and a functional compound with proven health benefits for the human body. Nevertheless, the poor water solubility and low oral bioavailability of lutein greatly limit its application. To address this, we developed an effective approach to enhance the water solubility of lutein through co-amorphous formulation. Specifically, the lutein-sucralose co-amorphous mixture was prepared at a molar ratio of 1:1 using ethanol and water as solvents by employing the solvent evaporation method, followed by solid-state characterization and dissolution testing conducted to assess the properties of the formulation. The X-ray diffraction pattern with an amorphous halo and the differential scanning calorimetry thermogram with no sharp melting peaks confirmed the formation of a binary co-amorphous system. Changes in peak shape, position, and intensity observed in the Fourier transform infrared spectroscopy spectrum revealed intermolecular interactions between lutein and sucralose molecules, while molecular dynamics simulations identified interaction sites between their hydroxyl groups. Additionally, dissolution testing demonstrated better dissolution performance of lutein in the co-amorphous form compared to pure lutein and physical mixture counterparts. Our findings present a novel strategy for improving the water solubility of lutein to make better use of it.

Efficacy of WaveOne Gold and ProDesign RT systems in removing filling material: a micro-CT analysis.

The remaining filling material after retreatment can harbor bacteria and organic tissues that can influence the outcome of the therapy. AIM: The aim of this study was to evalúate, by micro-CT, the amount of filling material remaining in the root canal after its removal using WaveOne Gold or ProDesign RT. MATERIAL AND METHOD: Forty human mandibular canines were instrumented with the ProTaper Next system up to the X2 instrument (25.06) and filled with gutta-percha cones and AHPlus. Teeth were divided into 2 groups (n=20): WaveOne Gold 25.07 (WOG) and ProDesign RT 25.08 (PRT) for filling removal, after which they were scanned in a micro-CT device to quantify the volume of remaining filling material. The data were subjected to log 10 transformation, Student 's t-test was performed to account for multiple observationsper sample, significance was set at 5%. RESULTS: Student 's t-test showed that there was no difference between the two systems regarding the volume of remaining filling material in the thirds: apical (p = 0.392), middle (p = 0.065), or cervical (p = 0.918). CONCLUSIÓN: Remaining filling material was present in all groups and both systems were similar in removing root filling material in mandibular canines.

A permanencia de material obturador após o retratamento pode abrigar bactérias e tecidos orgánicos que podem influenciar o resultado da terapia. OBJETIVO: O objetivo deste estudo foi avaliar, por micro-CT, a quantidade de material obturador remanescente no canal radicular após a desobturagdo com WaveOne Gold e ProDesign RT. MATERIAL E MÉTODO: Quarenta caninos inferiores humanos foram instrumentados com o sistema ProTaper Next até o instrumento X2 (25.06) e obturados com cones de guta-percha e AHPlus. Os dentes foram divididos em dois grupos (n=20): WaveOne Gold 25.07 (WOG) e ProDesign RT 25.08 (PRT) e escaneados em micro-CT para quantificagdo do volume de material obturador remanescente. Os dados foram submetidos á transformando log 10, o teste t de Student foi realizado para contabilizar múltiplas observagoes por amostra, a significáncia foi fixada em 5%. RESULTADOS: O teste t de Student mostrou que ndo houve diferenga no volume de material obturador remanescente entre os dois sistemas nos tergos: apical (p = 0,392), médio (p = 0,065) ou cervical (p = 0,918). CONCLUSÃO: O material obturador remanescente estavapresente em todos os grupos e ambos os sistemas foram semelhantes na remogdo do material obturador radicular nos caninos inferiores.

Irreducible Complex Posterior Elbow Dislocation with Varus Posteromedial Rotary Instability - A Case Report.

Introduction: Elbow dislocations, particularly those associated with varus posteromedial rotary instability, are relatively uncommon. We present the case of a 25-year-old male initially managed nonoperatively for a posterior elbow dislocation, who subsequently experienced irreducible re-dislocation with characteristic fractures of the anteromedial facet and tip of the coronoid, indicative of varus posteromedial rotary instability. Case Report: Following an unsuccessful attempt at closed reduction under general anesthesia, open reduction was performed, revealing the interposition of the posterior capsule of the humero-ulnar joint as the cause of irreducibility. Fixation of the coronoid fracture was undertaken, and the patient exhibited excellent functional outcomes at a 4.5-year follow-up. Conclusion: This case underscores the rarity of irreducible elbow dislocation in the context of varus posteromedial rotary instability and highlights the crucial role of capsular interposition in such cases. Successful open reduction, coronoid fixation, and attentive postoperative care contributed to the patient's favorable long-term functional outcome.

Rotary excitation of non-sinusoidal pulsed magnetic fields: Towards non-invasive direct detection of cardiac conduction.

PURPOSE: There is a need for high resolution non-invasive imaging methods of physiologic magnetic fields. The purpose of this work is to develop a MRI detection approach for non-sinusoidal magnetic fields based on the rotary excitation (REX) mechanism which was previously successfully applied for the detection of oscillating magnetic fields in the sub-nT range. METHODS: The new detection concept was examined by means of Bloch simulations, evaluating the interaction effect of spin-locked magnetization and low-frequency pulsed magnetic fields. The REX detection approach was validated under controlled conditions in phantom experiments at 3 T. Gaussian and sinc-shaped stimuli were investigated. In addition, the detection of artificial fields resembling a cardiac QRS complex, which is the most prominent peak visible on a magnetocardiogram, was tested. RESULTS: Bloch simulations demonstrated that the REX method has a high sensitivity to pulsed fields in the resonance case, which is met when the spin-lock frequency coincides with a non-zero Fourier component of the stimulus field. In the experiments, we found that magnetic stimuli of different durations and waveforms can be distinguished by their characteristic REX response spectrum. The detected REX amplitude was proportional to the stimulus peak amplitude (R2 > 0.98) and the lowest field detection was 1 nT. Furthermore, the detection of QRS-like fields with varying QRS durations yielded significant results in a phantom setup (p < 0.001). CONCLUSION: REX detection can be transferred to non-sinusoidal pulsed magnetic fields and could provide a non-invasive, quantitative tool for spatially resolved assessment of cardiac biomagnetism. Potential applications include the direct detection and characterization of cardiac conduction.

Ultrasonic Non-Destructive Detection Method for Residual Stress in Rotary Forging Aluminum Alloy Plates.

Aluminum alloy plates are widely used to manufacture large-scale integral structure parts in the field of aerospace. During the forming and processing of aluminum alloy plates, different degrees of residual stress are inevitably produced. Fast and accurate detection of residual stress is very essential to ensuring the quality of these plates. In this work, the longitudinal critically refracted (LCR) wave detection method based on a one-transmitter and double-receiver (OTDR) transducer and the finite element simulation were employed to obtain the residual stress. Aluminum alloy plates with different deformation amounts were fabricated by rotary forging to obtain different residual stress states. Results reveal that the plate formed by rotary forging is in a stress state of central tension and edge compression. As the deformation increases from 20% to 60%, the peak residual tensile stress increases from 156 MPa to 262 MPa, and there is no significant difference in the peak compressive stress. When the deformation reaches 60%, the difference in the residual stresses at different depths is less than 13%, which indicates that the plastic deformation zone basically penetrates the entire longitudinal cross-section of the plate. The maximum deviation between measurement and FE is 61 MPa, which means the experimental data are in good agreement with the FE results.

Effect of Rotary Swaging on Mechanical Behaviors of Axle Steel Rod.

The short-chain forming process using rotary swaging (RS) is an important method of achieving the manufacturing of lightweight axles. Axle steel, like 42CrMo, is widely used in many types of axles and shafts; however, there is no existing research on rotary-swaged axle steel's mechanical properties. It makes sense to carry out a comprehensive study on the effect of RS on the mechanical behaviors of axle steel rods. In this study, a 42CrMo steel rod was processed by RS through ten passes. The tensile properties, torsion properties, compression properties, and fatigue properties were tested. There was an overall improvement in the torsional and fatigue performance after RS. Combined with a finite element analysis (FEM), the uneven distribution of the dislocations and existence of the elongation material were inferred to have caused the different modes of the mechanical behaviors. Fracture surfaces were analyzed and the results showed that the fracture pattern had changed. There existed a competitive relation between the internal fatigue cracks and external cracks, which could be attributed to uneven strain hardening. This research proved the advantages of RS in the processing of axle parts, which mainly benefitted the torsional working conditions, and provided evidence for a new processing route for lightweight axles with RS.

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 study used scanned plastic teeth with genuine root canal anatomy and FEA to 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.

Electrochemical Properties of Nickel-Titanium Rotary Endodontic Instruments.

INTRODUCTION: Nickel-titanium rotary endodontic files have been commercially available for decades, but more recent innovations have introduced heat-treated and surface-treated files. This study investigated the corrosion properties of various nickel-titanium files in normal saline and sodium hypochlorite (NaOCl). METHODS: Ten different file brands of size 40 with a 0.04 taper were subjected to electrochemical testing in 0.9% NaCl (saline) and 5.25% NaOCl at room temperature. The Open Circuit Potential (OCP) was observed for 1 hour followed by a cyclic polarization test from -300 to 700 mV and back to -300 mV (vs OCP). Nonparametric ANOVA and a pairwise comparison (P < .05) were used for statistical analysis of the OCP at 1 hour and the corrosion current (Icorr) obtained via the cyclic polarization test. RESULTS: Significant differences (P < .05) were found between files with respect to OCP and Icorr in both solutions. Nine files exhibited significantly greater (P < .05) Icorrs in NaOCl than in saline. Conversely, pitting corrosion was observed in the saline solution but not NaOCl. Weak and/or moderate correlations existed between OCP and Icorr measures in the 2 solutions. CONCLUSION: Significant differences in electrochemical properties were observed among the 10 brands of files. Overall, there was not a clear trend between conventional, heat-treated, or surface-treated files among OCP or Icorr in either solution.

Waste Biomass-Mediated Synthesis of TiO2/P, K-Containing Grapefruit Peel Biochar Composites with Enhanced Photocatalytic Activity.

In this study, TiO2/P, K-containing grapefruit peel biochar (TiO2/P, K-PC) composites were synthesized in situ biomimetically using grapefruit peel as the bio-template and carbon source and tetrabutyl titanate as the titanium source. This was achieved using the two-step rotary impregnation-calcination method. Adjusting the calcination temperature of the sample in an air atmosphere could regulate the mass ratio of TiO2 to carbon. The prepared samples were subjected to an analysis of their compositions, structures, morphologies, and properties. It demonstrated that the prepared samples were complexes of anatase TiO2 and P, K-containing carbon, with the presence of graphitic carbon. They possessed a unique morphological structure with abundant pores and a large surface area. The grapefruit peel powder played a crucial role in the induction and assembly of TiO2/P, K-PC composites. The sample PCT-400-550 had the best photocatalytic activity, with the degradation rate of RhB, MO, and MB dye solutions reaching more than 99% within 30 min, with satisfactory cyclic stability. The outstanding photocatalytic activity can be credited to its unique morphology and the efficient collaboration between TiO2 and P, K-containing biochar.

Root Canal Instrumentation: Current Trends and Future Perspectives.

The evolution of root canal instrumentation techniques has significantly impacted the field of endodontics, enhancing both the efficiency and outcomes of treatments. This review outlines the transition from manual to mechanical and rotary instruments, highlighting the role of nickel-titanium (NiTi) alloys and smart technologies in advancing procedural precision and reducing patient discomfort. Key historical developments and technological innovations, such as digital imaging and navigation systems, are explored for their contributions to improved clinical outcomes and patient satisfaction. Additionally, the review addresses the challenges presented by the complex anatomy of the root canal system and the advent of current instrumentation techniques. The potential of emerging trends, including artificial intelligence and advances in materials science, is discussed in the context of future endodontic practices. Despite the progress, challenges related to using advanced instrumentation methods, ethical considerations, and the cost factor of new technologies persist. The present review underscores the ongoing need for research and development to further refine root canal instrumentation techniques, ensuring that advancements in endodontic care remain patient-centered and accessible.

Influence of Imposed Strain on Weldability of Dievar Alloy.

The presented work is focused on the influence of imposed strain on the weldability of Dievar alloy. Two mechanisms affecting the microstructure and thus imparting changes in the mechanical properties were applied-heat treatment (hardening and tempering), and rotary swaging. The processed workpieces were further subjected to welding with various welding currents. In order to characterize the effects of welding on the microstructure, especially in the heat-affected zone, and determine material stability under elevated temperatures, samples for uniaxial hot compression testing at temperatures from 600 to 900 °C, optical and scanning electron microscopy, and microhardness testing were taken. The testing revealed that, although the rotary swaged and heat-treated samples featured comparable microhardness, the strength of the swaged material was approximately twice as high as that of the heat-treated one-specifically 1350 MPa. Furthermore, it was found that the rotary swaged sample exhibited favorable welding behavior when compared to the heat-treated one, when the higher welding current was applied.