Search

The article details the first state assembly of the newly established DVS Landesverband Ost, held on June 11, 2024, in Jena, Germany, where attendees discussed the organization's structure. It emphasizes the importance of personal interaction for addressing complex topics in welding and materials testing, alongside the successful presentations and updates from various Bezirksverbände, noting a focus on membership engagement and event organization.

To investigate the influence of fabrication method on the biological properties of modified PEEK. Two materials were tested in this study: press and CAD/CAM milled ceramic-reinforced PEEK (BioHPP, Bredent, Germany). The residual diphenyl sulfone in these two materials was detected and their biological effects on human gingival fibroblasts (HGFs) were evaluated by assaying cell viability, apoptosis, and inflammation. Diphenyl sulfone was not detected in press and milled BioHPP. The cell viability of them complied with ISO standards. The mRNA expression levels of Bax and Caspase-3 were up-regulated and that of Bcl-2 was downregulated when HGFs were cultured with the eluates of these two materials. There was no difference in cell viability, apoptosis, and inflammation between them. Hence, the fabrication method did not affect the biological properties of modified PEEK, the press and CAD/CAM milled modified PEEK all presented favorable cytocompatibility despite the expression of apoptosis-associated genes at the mRNA level. [ABSTRACT FROM AUTHOR]

Conventional resistance spot welds are not visible from the outside. Therefore, it is not straightforward to evaluate the joint quality non-destructively. The pulse-echo method of manual ultrasonic is widely used for non-destructive testing. Another option is the passive magnetic flux density testing, which is being developed at Technische Universität Dresden, Germany. The spot weld is magnetized in the normal direction and the residual magnetic flux density is measured on top of the surface of the joint. This method is suitable for spot welds on typical car body steels. Previous investigations show that the magnetic properties of the materials influence the test result. In order to develop this new non-destructive testing method further, it is necessary to know the magnetic properties of the different microstructure regions of a spot weld. This article focuses on methods to measure and evaluate the magnetic properties of these regions, especially of the base material and the weld. Different measuring methods and approaches are presented and compared with each other. Based on the results, recommendations for future measurements for magnetic characterizations are given. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare surface roughness of three different types of chairside monolithic ceramic and ceramic-like CAD/CAM restorative materials finished and polished with two)stage diamond impregnated polishing disc systems. before- and after- clinician experience. For each test material such as: glass ceramic (VITA Mark II, VITA-Zahnfabric, Bad Sackingen, Germany), polymer infiltrated ceramic (VITA Enamic, VITA-Zahnfabric, Bad Sackingen, Germany), nano hybrid ceramic (Lava Ultimate, 3M-ESPE, Seefeld, Germany), 20 disc shaped specimens (radius=10mm, thickness=2mm) were prepared. Then each test groups were subdivided into two groups depending on operator’s experience. Finishing and polishing procedure was achieved before (n=10) and after (n=10) experience of operator, respectively. Average surface roughness (Ra) measurement were obtained using a surface profilometer. For each test group ten specimens were prepared and roughness was measured in five different positions using a profilometer with a traversing distance of 4 mm and a cut-off value of 0.8mm. The radius of the tracing diamond tip was 5µm and measuring force and speed was 4mN and 0.5 mm/s, respectively. The surface roughness of each individual disk was taken as the arithmetic mean of the Ra values measured in five different positions. It can be concluded that finishing and polishing of ceramic and ceramic-like CAD/CAM restorative materials are dependent both material structure and experience of operator. [ABSTRACT FROM AUTHOR]

Purpose: To compare the tissue composition of augmented sites after using two different synthetic bone substitute materials, nanocrystalline and nanoporous hydroxyapatite (HA), for sinus floor elevation and augmentation. Materials and Methods: Forty-four patients received 88 titanium screw implants (Camlog Promote plus) of 4.3-mm diameter and 11- or 13-mm length, placed simultaneously during sinus floor elevation and augmentation. Nanocrystalline (Ostim) or nanoporous (NanoBone) HA were used exclusively. Bone substitute materials and implant lengths were allocated by randomization. Bone biopsy specimens were obtained from the former area of the lateral access window at implant exposure during healing abutment placement after 6 months. Biopsy specimens were prepared and examined histologically and histomorphometrically. Results: All implants were osseointegrated at the time of exposure. Clinically and histologically, no signs of inflammation in the augmented sites were present. The histomorphometric analysis of 44 biopsy specimens revealed 31.8% ± 11.6% newly formed bone for sites augmented with nanocrystalline HA and 34.6% ± 9.2% for nanoporous HA (P = .467). The proportion of remaining bone substitute material was 28.4% ± 18.6% and 30% ± 13%, respectively (P = .453). The proportion of soft tissue within the biopsy specimens was 39.9% ± 11.1% and 35.4% ± 6.8%, respectively (P = .064). No significant differences were found between the area fractions of bone, bone substitute material, and soft tissue concerning the bone substitute material utilized. Conclusion: Within the present study, both synthetic bone substitute materials, nanocrystalline and nanoporous HA, were found to support bone formation in sinus floor elevation and augmentation procedures by osteoconductivity. They were not completely resorbed after 6 months. The amounts of newly formed bone, soft tissue, and bone substitute material remnants were found to be similar, indicating that both materials are likewise suitable for sinus floor elevation and augmentation procedures. [ABSTRACT FROM AUTHOR]

A majority of the German population would be willing to make their mobility data anonymous and openly accessible in order to develop new mobility offerings. Many want to improve traffic flow and optimize existing offerings. The majority believes that mobility offerings in Germany are too expensive and demands stronger support from the government. The digital association Bitkom is calling for a "right to digital education" for all people in Germany. Most companies want their employees to return to the office after the pandemic. The Science Council has published a position paper on science communication. The German MeSH, a biomedical thesaurus, is available for free download. The Rapid Alert System (RAS) was created to improve cooperation in the EU in dealing with disinformation. The Federal Institute for Materials Research and Testing (BAM) has launched a new research project database. An internal Facebook study shows that people with low digital competence are more often confronted with inappropriate content. [Extracted from the article]

The aim of this in-vitro study was to assess the two-body wear and to analyze wear behavior of different direct composite materials characterized by different filler load content but homogenous resin matrix composition, filler content size and kind. 144 disc-shaped specimens (5 mm in diameter, 2 mm-thick) were obtained from six different commercially available resin composite materials, characterized by an increasing filler load (% vol): ELS E, 49% vol (Saremco Dental AG, Switzerland); EvoCeram EC, 53-55% vol (Ivoclar, Liechtenstein); Z-250 Z, 60% vol (3 M ESPE, USA); Inspiro I, 65% vol (Edelweiss DR, Switzerland); Grandio G, 71,4% vol (Voco, Germany); and Clearfil Majesty Posterior M, 82% vol (Kuraray Dental, Japan). All specimens were fixed in a dual axis chewing simulator (CS-4.2, SD Mechatronik GmbH, Germany) specimen holder and exposed to the two-body wear test, against stainless steel antagonist (tip radius 2 mm/30° cone) (thermocycles 55°C/50°C, load 80 N/ 1.8 Hz). In each composite group, all the samples were further divided into three subgroups (n=8), according to the aging method, respectively for 150,000 (a), and 300,000 (b) and 600,000 (c) loading cycles. To assess the volume loss, 3D optical profilometric analysis was performed with a XY step sizes of 5 μm (CT 100, Cyber Technologies, Germany). Digital and scanning electron microscopy were used for qualitative analysis. Some samples were sectioned longitudinally to the wear scar to examine the depth trend of the microfractures. The statistical analysis was conducted using a two-way analysis of variance. The normality assumption required for the application of the method was verified using the Kolmogorov and Smirnov normality test (significance level: 0.05) while the homogeneity of variance was verified using the Levene's test. The profilometry analysis highlighted statistically significant differences between groups in terms of volumetric loss (mm3) but there were not always linear with the degree of load content. Microscopic images revealed wear patterns characterized by the presence of sub-superficial microcracking, mostly concentered at the arresting area of the indenter path but not homogeneously distributed in different groups. However, any signs of chemical micro-pitting were detected. The wear resistance caused by two-body wear differed among the restorative materials tested. In addition to the filler load, other factors could be involved in determining the mechanical characteristics of the material. [ABSTRACT FROM AUTHOR]

This work describes an approach for strain determination at the "in-plane" torsional test using digital image correlation (DIC) without brushing a statistical pattern on the specimen. It is well known that the in-plane torsion test represents a appropriate test method for material characterization of sheet metal in terms of yielding and kinematic hardening (Wagner et al. in Application of the in-plane torsion test in an industrial environment—recent advances and remaining challenges. In: Conference Paper of the 12th Forming Technology Forum, Herrsching, Germany, 2019). However, the gained measurement data do not allow the exact reading of material models for direct use in numerical analysis. The determination of shear values represents thereby the main challenge. Besides well-established methods for stress–strain analysis mentioned in this contribution, the applicability of DIC methods for the direct reading of distortion on the specimen has been investigated. Therefore, a torsion test rig has been developed and torsion tests using specimen out of mild- and high-strength steel have been conducted. The in-plane situation allows the distortion tracking of single points on the specimen by using a 2D image correlation software. The needed pictures were taken by using a common digital lens reflex camera. It has been shown that the resolution of the inherent specimen pattern is sufficient for the use of common 2D image correlation software. Torsional test results in the form of computed yield curves of mild- and advanced high-strength steels are aimed to be presented in this contribution. [ABSTRACT FROM AUTHOR]

Background: Interdental rubber picks (IRP) have become a frequent and convenient alternative for interdental cleaning. However, only little evidence exists supporting the effectiveness of newer designs available on the market. Therefore, a new in vitro model was evaluated to measure the experimental cleaning efficacy (ECE), as well as the force needed for insertion and during the use of IRP, with high reproducibility. Methods: Five different sizes of commercially marketed IRP with elastomeric fingers (IRP-F) (GUM SOFT-PICKS® Advanced, Sunstar Deutschland GmbH, Schönau, Germany) or slats (IRP-S) (TePe EasyPick™, TePe D-A-CH GmbH, Hamburg, Germany) were tested. Interdental tooth surfaces were reproduced by a 3D-printer (Form 2, Formlabs Sommerville, MA, USA) according to human teeth and matched to morphologically equivalent pairs (isosceles triangle, concave, convex) fitting to different gap sizes (1.0 mm, 1.1 mm, 1.3 mm). The pre−/post brushing situations at interdental areas (standardized cleaning, computer aided ten cycles) were photographically recorded and quantified by digital image subtraction to calculate ECE [%]. Forces were registered with a load cell [N]. Results: IRP-F have to be inserted with significant higher forces of 3.2 ± 1.8 N compared to IRP-S (2.0 ± 1.6 N; p < 0.001) independent of the size and type of artificial interdental area. During cleaning process IRP-S showed significantly lower values for pushing/pulling (1.0 ± 0.8 N/0.5 ± 0.4 N) compared to IRP-F (1.6 ± 0.8 N/0.7 ± 0.3 N; p < 0.001) concomitant to significantly lower ECE (19.1 ± 9.8 vs. 21.7 ± 10.0%, p = 0.002). Highest ECE was measured with largest size of IRP-F/IRP-S independent the morphology of interdental area. Conclusions: New interdental cleaning aids can be tested by the new experimental setup supported by 3D printing technology. Within the limitations of an in vitro study, IRP-F cleaned more effectively at higher forces compared to IRP-S. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the application of a fabricated dressing containing kaolin for skin regeneration in a rat model of excisional wounds. Method: In the present study, kaolin was loaded into electrospun polyvinyl alcohol (PVA)/chitosan polymer blend to develop a composite nanofibrous dressing. To make the yarns, kaolin with weight ratio of 5% was added to PVA/chitosan polymer blend and subsequently formed into nanofibres using the electrospinning method. Scaffolds were evaluated for to their microstructure, mechanical properties, surface wettability, water vapour transmission rate, water-uptake capacity, blood uptake capacity, blood compatibility, microbial penetration test, the number of colonies, and cellular response with the L929 cell line. Rats with full-thickness excisional wounds were treated with kaolin-containing and kaolin-free dressings. Results: The study showed that rats treated with the kaolin-incorporated mats demonstrated a significant closure to nearly 97.62±4.81% after 14 days compared with PVA/chitosan and the sterile gauze, which showed 86.15±8.11% and 78.50±4.22% of wound closure, respectively. The histopathological studies showed that in the PVA/chitosan/kaolin group, dense and regular collagen fibres were formed, while wounds treated with sterile gauze or PVA/chitosan scaffolds had random and loose collagen fibres. Conclusion: Our results show the potential applicability of PVA/chitosan/kaolin scaffolds as a wound care material. [ABSTRACT FROM AUTHOR]

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Monitoring of prestressed constructions with Acoustic Emission technique to detect wire breaks Acoustic Emission technique (AE) is successfully used for decades in material research, material testing in laboratory and in structural health monitoring, in machine building industry and plant engineering. Although AE has repeatedly proven its suitability for detecting damage, the method is not yet commonly used in civil engineering outside the laborytory. In Germany, several bridges are monitored permanently with AE to detect damage like prestressing wire breaks or breaks in welding seams [1]. AE to detect wire breaks is recommended for prestressed buildings with risk of stress crack corrosion, other crack risks or for buildings which cannot be inspected according the required standards. In this paper, examples for AE monitoring to detect wire breaks on bridges are shown. Furthermore, tests with the rebound hammer and wire breaks induced by cutting were executed and analysed. To confirm the test results and to provide better visualization and understanding of underlying wave phenomena, two numeric simulations of the sound wave propagation have been conducted. [ABSTRACT FROM AUTHOR]

To evaluate the surface roughness (Ra) of prosthetic crowns produced by four materials processed via CAD-CAM technology before and after chewing simulation (CS) against lithium disilicate crowns. Thirty-two crowns were processed via CAD-CAM, finished according to manufacturers' instructions and placed into four experimental groups (n=8): B (lithium disilicate, IPS/e.max-CAD), C (zirconia reinforced lithium silicate, Suprinity), D (polymer infiltrated ceramic network, Enamic) and E (indirect resin composite, Lava Ultimate). The antagonist crowns (A), were produced with lithium disilicate (IPS/e.max CAD) and named according to the crown against which they were tested (AB, AC, AD and AE). Prior to CS, all crowns were submitted to profilometric analysis to determine Ra (um). Seven readings were performed following ISO 4288. Crowns were submitted to CS (CS-4.2, SD-Mechatronik, Germany) against antagonist crowns under water (37°C/1 million cycles/30 N/1.5 Hz). After CS, roughness was measured again for all crowns. Data were analyzed using two-way ANOVA and Tukey's test (alpha=5%). The results are shown in Table 1. Lava Ultimate showed significantly higher roughness than all other materials both before and after CS. The other materials (Emax CAD, Suprinity and Enamic) showed similar mean roughness values before and after CS. For the antagonists, there were no significant differences among mean roughness values obtained for different specimen types before or after CS. Comparison of the mean values of each experimental group separately showed that there was no effect of CS on roughness for any of them. In the same manner, roughness of the antagonists was not affected by CS regardless of the crown material used in the experiment. The indirect resin composite displayed higher roughness than that measured for the ceramic and polymer infiltrated network materials tested regardless of the measuring moment (before or after CS). However, the numerical difference observed seems negligible from the clinical standpoint. There was no effect of CS of roughness for the tested crown materials and their antagonists. [Display omitted] [ABSTRACT FROM AUTHOR]

The effective development of icephobic coatings requires test scenarios that simulate relevant icing conditions in the desired application field. Because of a lack of available standardized tests, developers rely on comparative tests, comparing results with pre-defined benchmark systems. In this context, tests need to be conducted under very stable conditions without allowance for fluctuation. This guarantees a development process with stepwise material improvement. Fraunhofer IFAM in Germany began working on icephobic materials over 10 years ago, seeking to develop not only the materials but also adequate test methods. This chapter describes the development process and results of these activities, as well as proposals to improve efficiency further in the future development of icephobic materials. [ABSTRACT FROM AUTHOR]

Purpose: To report early clinical outcomes with a novel double-layer stent for the internal carotid artery (ICA) and the in vitro investigation of the stent's mechanical properties.Methods: A prospective single-center study enrolled 30 consecutive patients (mean age 73.1±6.3 years; 21 men) with symptomatic (n=25) or high-grade (n=5) ICA stenosis treated with the new double-layer carotid CGUARD Embolic Prevention System (EPS) stent, which has an inner open-cell nitinol design with an outer closed-cell polyethylene terephthalate layer. The average stenosis of the treated arteries was 84.1%±7.9% with a mean lesion length of 16.6±2.1 mm. In the laboratory, 8×40-mm stents where tested in vitro with respect to their radial force during expansion, the bending stiffness of the stent system and the expanded stent, as well as the collapse pressure in a thin and flexible sheath. The wall adaptation was assessed using fluoroscopy after stent release in step and curved vessel models.Results: The stent was successfully implanted in all patients. No peri- or postprocedural complications occurred; no minor or major stroke was observed in the 6-month follow-up. The bending stiffness of the expanded stent was 63.1 N·mm2 and (not unexpectedly) was clearly lower than that of the stent system (601.5 N·mm2). The normalized radial force during expansion of the stent to 7.0 mm, consistent with in vivo sizing, was relatively high (0.056 N/mm), which correlates well with the collapse pressure of 0.17 bars. Vessel wall adaptation was harmonic and caused no straightening of the vessel after clinical application.Conclusion: Because of its structure, the novel CGUARD EPS stent is characterized by a high flexibility combined with a high radial force and very good plaque coverage. These first clinical results demonstrate a very safe implantation behavior without any stroke up to 6 months after the procedure. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to assess the influence of surface treatment on the shear bond strength of two different adhesive-coated orthodontic ceramic brackets to computer-aided design/computer-aided manufacturing (CAD/CAM) nanohybrid composite., Methods: A total of 120 specimens (10 mm × 10 mm × 3 mm) were prepared from each type of CAD/CAM block (Grandio [GR], VOCO Cuxhaven, Germany; Lava Ultimate [LU], 3M ESPE, St. Paul, MN, USA). For each type of CAD/CAM block, the plates were divided into four groups based on the applied surface treatment: hydrofluoric acid (HF), grinding bur (GB), silica coating with CoJet system (CS), and titanium tetrafluoride (TiF 4 ) 2 wt/v%. Maxillary central incisors of adhesive-coated ceramic orthodontic brackets (APC Flash-free Clarity Advanced Ceramic, 3M Unitek, Monrovia, CA, USA) were bonded using Transbond XT Primer (3M Unitek, Monrovia, CA, USA). Shear bond strength was conducted, and the modes of failure were assessed utilizing the adhesive remnant index. Surface roughness and topography of treated CAD/CAM were evaluated. Data were statistically analyzed using two-way analysis of variance (ANOVA) and Tukey's test. The Weibull analysis was conducted on shear bond strength data., Results: Surface treatment with 2% TiF 4 wt/v revealed significantly higher bond strength (GR, 14.51 ± 2.57 MPa; LU, 11.19 ± 2.17 MPa) than other groups for both types of CAD/CAM restorative materials (p < 0.05). Adhesive failures were the predominant mode of failure. Surface treatment with CS revealed higher surface roughness than other groups (p < 0.05)., Conclusions: Surface treatment with 2% TiF 4 wt/v enhanced the adhesion between orthodontic ceramic brackets to GR and LU CAD/CAM composite restorative materials. GR CAD/CAM nanohybrid composite had higher bond strength than LU to ceramic orthodontic brackets., (© 2022. Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Copyright of Nachrichten aus der Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the framework of a doctoral thesis and in collaboration with the Brandenburg University of Technology Cottbus, Germany, full-scale field tests were carried out in Goldach, Switzerland, to check the functionality and the behavior of a new system with flexible steel components as reinforcement. Considering the aim of reducing risk due to sinkholes and finding a cost-effective solution, the system should be allowed to deform in the case of an event to make the critical section visually perceptible while not endangering road users. Therefore, the maximum allowed deflection depends on project-specific requirements. Compared to a rigid structure, a flexible component can react promptly to prevent a progressive breaking away of the subsoil. In the tests, an asphalt load-bearing layer as well as a concrete slab with a thickness of 0.20 m each were used. The modeled sinkhole exhibited a rectangular hollow with a free span width of 3.0 m. A total loading of 30.4 metric tons resulted in a depression in the center of the slab of ~0.20 m. The sinkhole protection system was installed right below the binder course and consists of a combination of linear bearing elements combined with a high-tensile steel wire mesh for force distribution. [ABSTRACT FROM AUTHOR]

The article offers information on several conferences related to non-destructive testing (NDT) in aerospace in 2012 including the Fourth International Symposium on Non-Destructive testing (NDT) in Aerospace which will be held in Augsburg, Germany on November 13-15, half-day aerospace workshop in Bristol, England on April 3, and 18th World Conference on Non-Destructive Testing at International Convention Center in Durban, South Africa.

The article presents a study on the application of bolted connections in fibre-reinforced polymers. The researchers conducted tests using standard stainless steel bolts and nuts and proposed load resistance models based on experiments. The researchers also determined a partial safety factor using the statistical methods given in EN 1990 and applied mechanically fastened connections to a GFRP pedestrian bridge built near Schwerin, Germany.

Aim: To test the hypothesis that in volume targeted ventilation modes, ventilator performance would vary according to ventilator type.Methods: Four neonatal ventilators: Draeger Babylog 8000 (Draeger Medical, Germany), SLE 5000 infant ventilator (SLE systems, UK), Stephanie paediatric ventilator (F. Stephan Biomedical, German) and V.I.P. Bird gold (Viasys Healthcare, USA) were assessed using a lung model. Delivered peak pressure, inflation time, mean airway pressure (MAP) and volume were measured.Results: At the same preset ventilator settings, the Stephanie and V.I.P. Bird ventilators delivered significantly lower peak pressures and tended to deliver lower MAPs than the other two ventilators. At a volume targeted ventilation level of 5 mL, the SLE and the V.I.P. Bird delivered significantly shorter inflation times. The above differences related to differences in the airway pressure waveforms delivered by the four ventilators. The V.I.P. Bird had a less variable volume delivery, but this was always significantly lower than the preset volume guarantee level but higher than the volume displayed by the ventilator.Conclusion: In volume targeted ventilation modes, performance differs between neonatal ventilator types; these results may have implications for clinical practise. [ABSTRACT FROM AUTHOR]

In 1928, Paul Katz (an employee of the Technische Hochschule Breslau) at the end of his paper "Die älteste eiserne Straßenbrücke des Europäischcn Kontinents" [I] wrote: "If we have managed to provoke an interest of the mentioned institutions (Technische Hochschule Breslau, German Museum of Technology in München, authorities of the city of Breslau) in preservation of the bridge in Laasan (Lażany), then our task has been fulfilled". Publication [I] mad much later papers [2-6], along with the present paper, stipulate similarly. Metallographic and strength tests made have shown that for construction of the bridge in Lażany unique material structure and architectonic solutions had been applied. The ports of the bridge structure have been made of grey pearlitic cast iron fulfilling all present-day requirements. There are still scarce preserved original ports of the bridge, whose documentation is available. Possibly, this is the last chance to rebuild the object, for example, in the settings of a Wroclaw park, thus maintaining it for posterity. [ABSTRACT FROM AUTHOR]

Purpose: Main goal of the study was the identification and quantitative analysis of monomer elution from materials commonly used in fixed orthodontic therapy. Studies have shown severe health effects of monomers including cytotoxic, allergenic or mutagenic potential and endocrine changes. This in vitro study focusses primarily on five resins which are usually processed intraorally and remain in the oral cavity long-term., Methods: We tested the elution of monomers from specimens (7.5 mm × 1.5 mm) immersed in artificial saliva at body temperature (37 °C) for 30 min to 5 weeks. The used method is in accordance with DIN EN ISO 10993-13. The five tested materials were BrackFix® (Voco GmbH, Cuxhaven, Germany), Triad®Gel (DeguDent GmbH, Hanau, Germany), and Transbond™ XT, LR and Plus (3M Unitek, Monrovia, CA, USA). All aliquots were analyzed using high performance liquid chromatography (HPLC). Data were statistically analyzed., Results: All five analyzed materials eluted substances over a period of 5 weeks. Identified substances included bisphenol A (BPA), triethylene glycol dimethacrylate (TEGDMA) and urethane dimethacrylate (UDMA). BPA eluted from Transbond™ Plus, XT, LR and BrackFix®. The cumulated mean values after 35 days ranged from 16.04 to 64.83 ppm, depending on the material. TEGDMA eluted with a mean of 688.61 ppm from Transbond™ LR. UDMA with a mean of 1682.00 ppm from Triad®Gel. For each material the highest concentrations of all these substances were found in the first elution period. Other substances that were not equivocally identified or of low concentration also eluted., Conclusion: Using the described method, it is possible to qualitatively and quantitatively determine the in vitro elution of monomers from orthodontic materials. The concentrations of the substances identified were below the current maximum recommended intake. However, a cumulative effect and low-dose effects should be considered for both patients and dental professionals, especially for young patients. Measures to reduce exposure patients and practitioners are suggested., (© 2021. The Author(s).)

Introduction: Understanding the physicochemical and biological properties of endodontic sealers is important for endodontic treatment planning. This study evaluated the properties of EndoSequence BC Sealer HiFlow (BCH; Brasseler USA, Savannah, GA), EndoSequence BC Sealer (BC, Brasseler USA), and AH Plus (AHP; Dentsply DeTrey, Konstanz, Germany). The effect of temperature on the setting time and flow of these sealers was also evaluated., Methods: The setting time, flow, radiopacity, pH, solubility, and calcium release were investigated following ISO guidelines. The morphology and chemical composition of the sealers were evaluated by scanning electron microscopy and energy-dispersive spectroscopy. The antibacterial activity of sealers was tested against 2 strains of Enterococcus faecalis. Sealer cytotoxicity and the effects on messenger RNA expression of proinflammatory and mineralization genes were also investigated. Data analysis was performed using analysis of variance, Tukey, Kruskal-Wallis, and Dunn multiple comparison tests. P ≤ .05 was considered statistically significant., Results: The setting time and flow rate of all sealers were affected by heat (P ≤ .05). The setting times and solubility of BCH and BC were significantly higher than AHP (P ≤ .0001). The radiopacity of AHP was higher than BCH and BC (P ≤ .0001). All sealers were alkaline and had antibacterial effects. Cell viability was higher for BCH and BC than AHP (P ≤ .0001). No significant differences in messenger RNA expression of proinflammatory and mineralization genes were observed., Conclusions: Overall, BCH and BC had similar physicochemical and biological properties. The observed high solubility of BCH and BC as well as the high cytotoxicity of AHP might negatively impact the clinical performance of these materials. The application of heat affected the setting time and flow of all sealers., (Copyright © 2021 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Background/aim: With the demographic change and associated chronic bone loss, the need for cytocompatible bone replacement materials arise in modern medicine. The aim of this in vitro study was to investigate the cytocompatibility of eleven different bone substitute materials and membranes., Materials and Methods: Seven bone substitute materials and four membranes were assessed in vitro. The specimens were tested based on their interaction with MC3T3 pre-osteoblasts, through the utilization of viability, proliferation, and cytotoxicity assays. Cell vitality was evaluated using live-dead staining., Results: Although we found minor differences in cytocompatibility among the assessed materials, all tested materials can be considered as cytocompatible with a viability of more than 70% of the negative control, which indicates the non-toxic range as defined in current, international standards (DIN EN ISO 10993-5:2009, German Institute for Standardization, Berlin, Germany). Direct live-dead staining assays confirmed satisfactory cytocompatibility of all tested membranes., Conclusion: All examined bone substitute materials and membranes were found to be cytocompatible. In order to assess whether the observed minor differences can impact regenerative processes, further in vivo studies need to be conducted., (Copyright © 2021 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background and Aim: In order to support children's compliance with orthodontic treatment, glitter particles containing aluminium (Al) are often embedded in the acrylic of removable appliances. When worn for up to 16 h daily for 2-3 years, it can be assumed that Al ions diffuse into saliva over time. The aim of this study was to investigate the release of Al ions from the acrylic using different orthodontic wires., Materials and Method: Test specimens (surface area 5.65 cm 2 ) were prepared from orthodontic resin and various wires; half contained aluminium glitter particles. The test specimens were placed in Petri dishes containing 50 ml of corrosion medium (pH 2.3) according to DIN EN ISO 10271 at 37 °C for 7 days. Inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify the specific ions in the corrosion solution., Results: Statistical analysis showed a significant difference in the concentration of Al ions between samples with and without glitter particles. Concentrations from samples with glitter reached up to 14,474 μg/l Al ions; samples without glitter contained on average 1260 μg/l. A small proportion of the Al ions may originate from the alloys of the wires., Conclusions: It should be investigated whether the aluminium concentration can lead to health risks for humans. In view of the findings, orthodontists should not offer appliances containing glitter in order to minimize aluminium uptake with saliva. It needs to be clarified whether the conditions found in the oral cavity lead to the same results as under the abovementioned conditions. Legislation should be developed to limit the release of aluminium from orthodontic products.

Indoor air quality can be adversely affected by emissions from building materials, consequently having a negative impact on human health and well-being. In this study, more than 30 natural building materials (earth dry boards and plasters, bio-based insulation materials, and boards made of wood, flax, reed, straw, etc.) used for interior works were investigated as to their emissions of (semi-)volatile organic compounds ((S)VOC), formaldehyde, and radon. The study focused on the emissions from complete wall build-ups as they can be used for internal partition walls and the internal insulation of external walls. Test chambers were designed, allowing the compounds to release only from the surface of the material facing indoors under testing parameters that were chosen to simulate model room conditions. The emission test results were evaluated using the AgBB evaluation scheme, a procedure for the health-related evaluation of construction products and currently applied for the approval of specific groups of building materials in Germany. Seventeen out of 19 sample build-ups tested in this study would have passed this scheme since they generally proved to be low-emitting and although the combined emissions of multiple materials were tested, 50% of the measurements could be terminated before half of the total testing time. [ABSTRACT FROM AUTHOR]

Introduction: The present study aimed to compare the torsional strength of the initial files of the Mtwo (VDW, Munich, Germany) and novel Rotate systems (VDW, Munich, Germany) with the ProGlider (Dentsply Sirona, Ballaigues, Switzerland) and R-Pilot (VDW) glide path instruments., Methods: The Mtwo (10/.04), ProGlider (16/.02), R-Pilot (12.5/.04), and Rotate (15/.04) glide path files were compared regarding their torsional strength, which was tested using a specially designed test device (N = 20). The data obtained were statistically analyzed at 5% significance level using 1-way analysis of variance and the post hoc Tukey test. The fragment surfaces and separated instruments were examined with ×50, ×100, and ×1000 magnification under a scanning electron microscope., Results: The R-Pilot group showed the highest torsional strength value among all groups (P < .05), whereas there was no significant difference between the torsional strength values of the Mtwo and ProGlider groups (P > .05). The Rotate group had the lowest torsional strength among all groups (P < .05). The Mtwo group showed the lowest angle of rotation among all groups (P < .05)., Conclusions: Although the R-Pilot glide path file exhibited the highest torsional strength in all groups, Rotate showed the highest angle of rotation. Differences in torsional resistance of the instruments may be associated with their manufacturing methods and design features., (Copyright © 2021 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The purpose of this study was to assess the antimicrobial activity and flow of root canal sealers after incorporating novel highly loaded antimicrobial drug-silica coassembled particles (DSPs)., Methods: DSPs were synthesized through coassembly of silica and octenidine dihydrochloride (OCT) antimicrobial surfactant. DSPs were loaded (1% and 2% wt) into epoxy resin sealer (AH Plus [AH]; Dentsply DeTrey GmbH, Konstanz, Germany) or calcium silicate-based sealer (EndoSequence Bioceramic Sealer (BC); Brasseler, Savannah, GA). OCT release from DSP-modified sealers was determined using liquid chromatography. Antimicrobial activity of sealers against planktonic or biofilm form Enterococcus faecalis was assessed using direct contact and membrane restricted tests. Sealer flow was tested according to ISO6876:2012., Results: OCT release from BC + 1% or 2% DSPs was above the minimum inhibitory concentration following 2 days throughout the 30-day experiment, whereas OCT release from AH + 1% or 2% DSP was significantly below the minimum inhibitory concentration against E. faecalis (4 μg/mL) over the whole 30-day experimental period. All materials (with or without DSPs) killed planktonic bacteria initially. AH ± 1% or 2% DSPs had no antimicrobial activity after 7 days. BC + 1% or 2% DSPs maintained antibacterial activity over the 30-day period. Both modified and unmodified sealers completely inhibited the growth of E. faecalis biofilms after 24 hours of contact. DSPs decreased the flow of AH and BC sealers; for AH, the reduction was proportional to the amount of DSPs added. All modified and unmodified sealers, except for AH + 2% DSPs, were within the acceptable limits of ISO 6876 flow tests., Conclusions: DSPs enhanced the antimicrobial performance of BC but not AH, whereas the material's flow remained compliant with ISO 6876 standards. Depending on the sealer, DSPs may enhance antimicrobial efficacy in root canal treatment and potentially improve treatment outcome., (Copyright © 2021 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Background: The aim of this study was to compare the influence of two novel reciprocating movements on the cyclic fatigue resistance of endodontic reciprocating files., Methods: 30 Procodile® (Komet Medical, Lemgo, Germany) files were selected in this study and distributed according to the following study groups depending on the movements to be performed: ReFlex Dynamic (n = 10), ReFlex Smart (n = 10) and Reciproc (n = 10) reciprocating movement. These files were fixed to a specific dynamic cyclic fatigue device designed and manufactured by 3D impression to simulate the pecking motion performed by the operator. The time to failure and the number of cycles of in-and-out of the endodontic files was registered. The results were analyzed by ANOVA and Weibull statistics., Results: Statistically significant differences were found when the number of cycles of in-and-out movement and the time to failure of ReFlex Dynamic and Reciproc reciprocating movement (p < 0.001) and between ReFlex Smart and Reciproc reciprocating movement (p < 0.001) were compared in pairs. However, no statistically significant differences were observed between time to failure and number of cycles of in-and-out movement of ReFlex Dynamic and ReFlex Smart reciprocating movement (p = 0.253)., Conclusions: The ReFlex Smart reciprocating movement increased the cyclic fatigue resistance of endodontic reciprocating files compared with traditional reciprocating movement.

Background: The purpose of the presented investigation is to evaluate the resulting torque on loaded 3D printed springs using different coil thickness and length., Methods: Specimens were designed and printed using the 3D printer MAX (Asiga, Sydney, Australia) with 3D printable, experimental, flexible material (Code:BM2008, GC, Tokyo, Japan). The specimens were divided into three groups according to spring coil design. Control group (n = 18), length group (n = 19) and thickness group (n = 22). Groups were tested using a Sauter Machine for torque calculation (DB, Grindelwald, Switzerland) in conjunction with a universal testing machine (Zwick Z010, Ulm, Germany) for clock-wise and anti-clockwise testing. Statistical analysis was performed using the Steel-Dwass test to compare median values of the three groups in both testing directions (p < 0.001)., Results: The highest torque value was determined in the thickness group for both clockwise and anti-clockwise testing directions, achieving 44.00 N/mm and 39.62 N/mm respectively. The length group ranged from 21.65 to 11.04 N/mm in clockwise direction and from 18.04 to 11.38 N/mm in counter-clockwise testing. The control group ranged from 22.72 to 17.18 N/mm in the clock-wise direction while in the anti-clock wise testing it ranged from 21.34 to 16.02 N/mm., Conclusions: The amount of torque produced from the computer aided designing/computer aided manufacturing (CAD/CAM) springs is being affected by diameter more than the length design parameter in comparison to the control group. The values of the thickness group are significantly higher than those of the length group (P < 0.001).

Introduction: This study aimed to compare the torsional resistances and fracture modes of WaveOne Gold (Dentsply Sirona, Ballaigues, Switzerland) and Reciproc Blue (VDW, Munich, Germany) using the repetitive torsional loading (RTL) method and the conventional single-rotation (STL) method., Methods: A 3-mm file tip was fixed with a brass plate, and a torsional load was applied using a custom device. In the RTL method, the file was driven counterclockwise at 50 rpm until it achieved the preset torque of 0.5 Ncm; thereafter, it was returned to its original position. This recovery of the file to its original position was defined as 1 torsional loading cycle; the number of repetitive load cycles until fracture was counted. In the STL method, the files were rotated at a constant rate of 2 rpm in a counterclockwise direction until file fracture. The fragments fractured by the 2 methods were compared under a scanning electron microscope to examine the topographic features of the fractured surfaces and longitudinal aspects., Results: With the RTL method, Reciproc Blue showed a higher number of repetitive load cycles until fracture than WaveOne Gold (P < .05). With the STL method, Reciproc Blue also had a higher ultimate strength than WaveOne Gold (P < .05). Scanning electron microscopic findings of the fractured specimens from the 2 test methods showed different features of torsional failure., Conclusions: Within the study limitations, both the RTL and STL methods conferred similar torsional resistance. Therefore, the clinically relevant RTL method with repetitive and reciprocation motion can be used for testing torsional resistance., (Copyright © 2020 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Objectives: To analyse the residual monomer (MMA) elution of polymethyl methacrylate (PMMA) in distilled water after diverse fabrication methods and aging procedures., Materials and Methods: PMMA specimens (N = 192, PalaXpress; Kulzer, Hanau, Germany) were manufactured (pouring, n = 96/injection, n = 96) and polymerized in water (55°C) without pressure (n = 48) and with 2 bar pressure (n = 48). Specimens were grinded (n = 24) or polished (n = 24) and aged for 12 h in distilled water/37°C (n = 12) or at air/20°C (n = 12) and stored afterwards in distilled water at 37°C. MMA elution was evaluated after 1, 2, 3, 4, 5, 6, 7, 10, 15 days (UV/Vis spectrophotometry). Data were analysed with Kolmogorov-Smirnov, Mann-Whitney-U and Cohen-d test using SPSS (α < 0.5)., Results: The pouring procedure resulted in significantly higher MMA elution than the injection procedure up to 5 days. Polymerization with a pressure of 2 bar reduced the MMA elution significantly for poured specimens. Polishing reduced the MMA elution in comparison to grinding., Conclusions: The fabrication procedure (pouring/injection) showed the strongest correlation to the MMA elution (r = 0.500), followed by polishing (r = 0.243), the pressure during polymerization (r = 0.109) and the storage medium (r = 0.053)., Clinical Relevance: Higher MMA elution may increase the risk of chemical irritations, allergic reactions and hypersensitivities of the oral mucosa. Technicians and dentists should be aware about the elution differences dependent on the fabrication procedure.

Aim: To evaluate the bending, buckling and torsional resistance of ProGlider (PG) (Dentsply Sirona, Ballaigues, Switzerland), R-Pilot (RP) (VDW, Munich, Germany) and WaveOne Gold Glider (WOGG) (Dentsply Sirona)., Methodology: Ninety instruments were used: 30 PG (size 0.16, .02v taper), 30 RP (size 0.125, .04 taper) and 30 WOGG (size 0.15, .02v taper). The bending resistance test was performed on 10 randomly selected instruments of each system according to ISO 3630-1 specifications. For the buckling resistance test, a loading was applied in the axial direction of each instrument using a universal test machine, with a 20 N cell and 15 mm min -1 speed, in the axial direction. When a lateral elastic displacement of 1 mm occurred, the force was registered. The torsional resistance test was performed according to ISO 3630-1 specifications. Statistical analysis was performed using one-way anova and post hoc Student-Newman-Keuls test (P < 0.05)., Results: WOGG had the lowest bending resistance, whilst RP had the highest bending resistance (P < 0.05). RP also had the highest buckling resistance, and WOGG had the lowest (P < 0.05). PG had intermediate results regarding bending and buckling resistance, with significant differences to RP and WOGG (P < 0.05). RP had the highest torsional strength and the lowest angular deflection when compared to PG and WOGG (P < 0.05). No differences in the torsional strength and angular deflection were observed between WOGG and PG (P> 0.05)., Conclusion: The glide path instruments had different behaviours in term of bending, buckling and torsional resistance., (© 2020 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Introduction: Bio-C Sealer (BC; Angelus, Londrina, PR, Brazil) and Sealer Plus BC (SPBC; MK Life, Porto Alegre, Brazil) are new ready-to-use bioceramic endodontic sealers. The aim of this study was to evaluate the biocompatibility and bioactive potential of BC and SPBC sealers in comparison with AH Plus (AHP; Dentsply DeTrey Gmbh, Konstanz, Germany) in subcutaneous tissue of rats., Methods: Polyethylene tubes filled with materials and empty tubes, serving as the control group, were implanted in the subcutaneous tissues of rats. After 7, 15, 30, and 60 days, the tubes with connective tissue were removed, and inflammatory cells (ICs)/mm 2 and immunolabeled cells for interleukin (IL)-6 were evaluated. Osteocalcin and von Kossa analysis were also performed. Data were submitted to analysis of variance and Tukey tests, with a significance level of 5%., Results: At 7 days, SPBC showed lower ICs than BC (P < .05). AHP exhibited greater immunolabeled cells for IL-6 (P < .05). After 15 days, BC showed lower ICs and IL-6 compared with other materials. At 30 days, SPBC and AHP showed higher values for ICs (P < .05). After 60 days, calcium silicate sealers did not show statistical difference (P > .05) for ICs and IL-6, with values lower than AHP (P < .05). The materials showed positive structures to von Kossa staining. BC exhibited osteocalcin labeling in all periods. SPBC showed osteocalcin labeling from 15-60 days. AHP and the control group did not exhibit osteocalcin labeling., Conclusions: BC and SPBC sealers are biocompatible and present bioactive potential., (Copyright © 2020 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

The OneTouch Verio Reflect blood glucose monitor (BGM) has market clearance in several countries based in part on fulfilling the lay user and system accuracy criteria described in ISO15197:2015. However, the Food and Drug Administration (FDA) does not recognize the accuracy criteria in ISO15197 as a basis for gaining regulatory clearance for these devices. The current study evaluates the BGM using the accuracy guidelines issued by the agency for self-monitoring blood glucose test systems for over-the-counter use. Glucose results were accurate vs comparator over a wide glucose range and met lay user and glucose accuracy criteria at extreme glucose values as described in the FDA guidance. Clinicaltrials.gov NCT03851549 .

Aim: To evaluate in a laboratory setting the effects of Endosequence BC Sealer HiFlow (Brasseler USA, Savannah, GA, USA), a novel calcium silicate-based sealer developed for use in warm canal filling techniques, on human periodontal ligament stem cells (hPDLSCs)., Methodology: Eluates of EndoSequence BC Sealer HiFlow (BCHiF) (Brasseler USA), EndoSequence BC Sealer (BCS) (Brasseler USA) and AH Plus (AHP) (Dentsply DeTrey GmbH, Konstanz, Germany) were placed in contact with hPDLSCs. The characterization of the chemical elements of the root canal sealers was assessed using scanning electron microscopy and energy-dispersive X-ray analysis (SEM-EDX). Inductively coupled plasma-mass spectrometry (ICP-MS) was used to determine the ion release of the sealers. MTT assay and wound healing techniques were used to determine cell viability and migration, respectively. Cell morphology and cell attachment were assessed using a direct contact technique of hPDLSCs onto the surface of the sealers and analysed by SEM. The bioactivity potential was carried out with the Alizarin Red and qPCR testing methods. The statistical differences were evaluated using one-way anova and Tukey's test (P < 0.05)., Results: ICP-MS and EDX revealed significantly more zirconium in BCHiF than BCS (P < 0.05), whereas BCS had slightly higher levels of Ca 2+ than BCHiF (P < 0.05). The cell viability assay revealed no relevant differences between BCS and BCHiF when compared with the control group (P > 0.05). Both BCS and BCHiF had similar rates of cell migration to the control group at 24 and 48 h. Cell morphology and adhesion capacity were also similar for BCS and BCHiF groups, whilst the AHP group was associated with reduced adhesion capacity. The Alizarin Red assay revealed a significant difference between the BCS and the control group (P < 0.001), as well as for the BCHiF group (P < 0.001). Finally, BCS and BCHiF promoted overexpression of osteo/cementogenic genes., Conclusions: In general, EndoSequence BC Sealer HiFlow possesses suitable biological properties to be safely used as a root canal filling material and promote increased expression of oste/cementogenic genes by hPDLSCs., (© 2020 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Objective: The goal was to evaluate the adhesive shear bond strength (SBS) of orthodontic tubes bonded to molar teeth and reinforced with Transbond XT (3M Science, St. Paul, MN, USA) and flowable resin., Materials and Methods: In all, 120 molar teeth, previously extracted from patients with a mean age of 30 were included. Orthodontic molar tubes were bonded on the vestibular surface of these teeth with one of two types of adhesive (Transbond XT [3M Science, St. Paul, MN, USA] or Orthobond [Morelli, Sorocaba, Brazil]). Each of these groups was subsequently divided into four further groups: control and those subjected to the use of resin reinforcement on the occlusal surface of the bonded tubes with one of three materials (Transbond XT, Tetric N Flow [Ivoclar Vivadent, Ellwangen, Germany], Z 350 Flow [3M Science, St. Paul, MN, USA]). SBS and adhesive remnant index tests were performed to evaluate bond strength and type of fracture of the tubes bonded with the different methods., Results: The use of resin reinforcement with Transbond XT significantly increased the SBS of tubes bonded with both materials. Flowable composites did not increase the SBS when used as a reinforcement. Less than 50% of the adhesive remained on the vestibular surface after the SBS test in most samples of all groups., Conclusion: Transbond XT orthodontic adhesive and Orthobond adhesive had appropriate bonding strengths for clinical use. Furthermore, the use of a resinous reinforcement with Transbond XT significantly increased the SBS of tubes bonded. However this technique with flowable adhesives (Tetric N Flow and Z350 Flow) did not significantly increase SBS when orthodontic tubes were bonded with Transbond XT or Orthobond.

Introduction: This study aimed to evaluate the effect of ultrasonic activation (UA) of endodontic sealers on dentin tubule penetration and the bond strength to root dentin., Method: One hundred single-rooted teeth were prepared with 40.06 nickel-titanium instruments and divided into 2 groups: with or without UA. Three resin-based sealers (MTA Fillapex [Angelus Dental Solutions, Londrina, PR, Brazil], Sealer Plus [MK Life Medical and Dental Products, Porto Alegre, RS, Brazil], and AH Plus [Dentsply, DeTrey GmbH, Konstanz, Germany]; n = 20) and 2 calcium silicate-based sealers (Sealer Plus BC [MK Life Medical and Dental Products] and EndoSequence BC [Brasseler, Savannah, GA], n = 20) were used and subdivided (n = 10) according to the protocols. Fluo-3 (Thermo Fisher Scientific, Waltham, MA) and rhodamine B dyes were added to the calcium silicate- and resin-based sealers, respectively. In the UA groups, the activation was performed for 40 seconds followed by lateral compaction. Samples were transversely sectioned to evaluate the dentin tubule penetration and the bond strength to root dentin. The penetration data were analyzed with the Student t test, 1-factor analysis of variance, and Bonferroni tests. Bond strength was evaluated using the Student t test, Kruskal-Wallis, and Dunn post hoc test., Results: Resin-based sealers showed the highest tubule penetration without UA (P < .05). UA significantly enhanced MTA Fillapex and Endosequence BC dentin tubule penetration (P < .05). AH Plus and Sealer Plus BC improved their bond strength to root dentin after UA (P < .05). AH Plus/UA, Sealer Plus/UA, and Sealer Plus BC/UA presented the highest bond strength values (P < .05). Adhesive failures were predominant in all groups regardless of the use of ultrasound., Conclusions: UA interferes with tubule penetration and the bond strength to root dentin of resin- and calcium silicate-based sealers., (Copyright © 2020 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The aim of the present study was to assess the effects of different silicate-based sealers (ie, BioRoot RCS [Septodont, Saint Maur des Fosses, France], ProRoot ES [Dentsply Sirona, York, PA], and MTA Fillapex [Angelus, Londrina, PR, Brazil]) on cytokine production and viability of human periodontal ligament stem cells (PDLSCs). AH Plus (Dentsply DeTrey GmbH, Konstanz, Germany) was used as a reference material., Methods: PDLSCs were cultured either in 2-dimensional or 3-dimensional conditions (in 0.15%-0.5% PuraMatrix [BD Biosciences, Bedford, MA]) for 24 hours with eluates from set endodontic sealers. Additionally, the toxicity of eluates from endodontic sealers was evaluated using an in vitro root model experimental procedure. PDLSC viability was determined using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay. PDLSC culture medium was used for cytokine quantification (interleukin [IL]-6, IL-8, growth-regulated oncogene, IL,-4 and IL-10) using the HCYTMAG-60K-PX41 Milliplex kit (EMD Millipore, Burlington, MA)., Results: In 2-dimensional culture conditions, BioRoot RCS revealed a good PDLSC viability rate. ProRoot ES had no effect on PDLSC viability regardless of the dilution. MTA Fillapex was strongly cytotoxic even at the lowest extract dilutions (1:1, 1:2, and 1:4). Encapsulation of PDLSCs in PuraMatrix tended to decrease the cytotoxic effect of the sealers. In the 3-dimensional in vitro root model experimental procedure, BioRoot RCS, ProRoot ES, and MTA Fillapex revealed a cytocompatibility pattern. Different calcium silicate-based sealers exhibited different proinflammatory cytokine production. BioRoot RCS greatly stimulated the release of IL-10 and, to a lesser degree, IL-4 by PDLSCs (P < .05)., Conclusions: BioRoot RCS and ProRoot ES did not induce proinflammatory cytokines and promoted anti-inflammatory cytokine secretion by PDLSCs that may have a positive local impact by attenuating an initial inflammatory response., (Copyright © 2020 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The purpose of this study was to investigate the influence of both polymerization cycles and mechanical exposure procedures on the adhesion of instrument fragments using a modified tube technique with a light-curing composite., Methods: Eighty Mtwo instruments (size 15.05; VDW, Munich, Germany) were cut at a diameter of 35/100 mm and clamped in a vice with an overlap of 2 mm. Matching cannulas were filled with SDR composite (Dentsply, York, PA) and placed over the instruments. Prime & Bond Active (Dentsply Sirona, Bensheim, Germany) was used as the bonding material. Glass fiber was inserted from the opposite side into the cannula, and 1, 2, 4, or 6 polymerization cycles of 30 seconds were applied (800 mW/mm 2 ) (n = 20/group). Sixty further identical instruments (n = 20/group) were divided into the following groups: group 1, cut at 10 mm and left unprepared (taper = 5%); group 2, parallelized using diamond instruments (taper = 0%); and group 3, prepared in a way that an inverted conical taper resulted (taper = 2%). Polymerization was performed for 2 minutes. The failure load and mode of failure were determined using a tensile testing device (2 mm/min). Data were statistically analyzed using the Kruskal-Wallis or chi-square test., Results: The failure load increased significantly with the number of polymerization cycles (P < .0001). More than 4 polymerization cycles had no further benefit (P > .05). The failure load in the inverted conical group was significantly lower (P < .0001) compared with the parallel and the unprepared groups. Adhesive failure was significantly more frequent in groups 2 and 3 (20/20) than in group 1 (16/20) (P < .05)., Conclusions: Both the number of polymerization cycles and the mechanical exposure procedures had a significant impact on the adhesive force when using the tube technique., (Copyright © 2020 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: This study evaluated the effect of residual substances derived from irrigant solutions and intracanal medications on the rheological properties of a silicone, gutta-percha, and bioactive glass-based sealer in comparison with an epoxy resin-based sealer., Methods: Thin films of contaminants (0.5 μL) (3% sodium hypochlorite [NaOCl], chlorhexidine digluconate [CHX], 17% EDTA, calcium hydroxide, 40% citric acid, or distilled water [DW]) were applied along with freshly mixed GuttaFlow Bioseal (GFB; Coltene/Whaledent, Langenau, Germany) or AH Plus Jet (Dentsply DeTrey, Konstanz, Germany) on the lower plate of a dynamic rheometer. Rheological measurements were performed in oscillating mode at the strain amplitude, angular frequency, and constant temperature of 0.01%, 10 rad/s, and 37°C, respectively. Samples without contaminants served as controls. All measurements were performed 5 times. The Kolmogorov-Smirnov test and 1-way analysis of variance followed by the Student-Newman-Keuls test were performed to analyze the results (P < .05)., Results: The contaminants did not alter the setting time of GFB compared with the controls; however, CHX and calcium hydroxide decreased its complex viscosity (ƞ*) (P < .05). The setting time of AH Plus Jet was increased by DW, CHX, citric acid, and EDTA (P < .05). All contaminants decreased its ƞ* at the setting point (P < .05). NaOCl led to the greatest alteration of its rheological parameters., Conclusions: Irrigant solutions and intracanal medications adversely affected at least 1 of the tested rheological properties of both sealers, except for DW and 3% NaOCl, which did not alter any rheological property of GFB., (Copyright © 2019 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Purpose: To survey dentists in Germany regarding their preferred cementation regimen for fixed dental prostheses (FDPs) fabricated from various restorative materials. Materials and Methods: An online survey was developed for completion by dentists in Germany between 08/2019 and 02/2020. The questionnaire gathered information about the cementation regimen (conventional, including the acid-base cements zinc-oxide phosphate or any glass-ionomer cement; self-adhesive; adhesive; don’t know) that the participant would preferably select for the insertion of single- or multi-unit FDPs fabricated from various restorative materials. Data were also collected on demographic and personal characteristics. Results: A total of 721 dentists completed the survey, and the data from 688 questionnaires were included in the analysis. Conventional cementation was the option of choice for restorations fabricated from alloy/porcelain-fusedto- metal among 91.0% of the participants and for restorations fabricated from polycrystalline ceramics among 42.9% of the participants. Adhesive cementation was preferred for restorations fabricated from feldspathic/leucitereinforced glass ceramics (77.9%), lithium-disilicate glass ceramics (67.5%), zirconia-reinforced lithium-silicate glass ceramics (42.0%), and CAD/CAM resin composites (63.8%). Uncertainties regarding the appropriate cementation protocol for restorations fabricated from CAD/CAM resin composites were reported by 15% of the participants. More than 20% of the participants selected a technique that is less or not at all recommended for the cementation of restorations fabricated from zirconia-reinforced lithium-silicate glass ceramic and CAD/CAM resin composites. Conclusion: The results of the survey suggest that dentists in Germany select the cementation regime depending on the restorative material. Some of the participating dentists selected cementation regimens that are less or not at all recommended for restorations fabricated from zirconia-reinforced lithium-silicate glass ceramic and CAD/CAM resin composites, or were not sure about the appropriate cementation protocol.

Aim: To compare the martensitic transformation temperatures and torsional resistance behaviour of classic M-Wire Reciproc and Reciproc blue files (VDW, Munich, Germany)., Methodology: M-Wire classic Reciproc R25 and Reciproc blue R25 instruments were used. Transformation temperatures were determined by differential scanning calorimetry (DSC-DSC 60, Shimadzu, Kyoto, Japan). Three samples with approximately 20 mg of each system were cooled to -120 °C and then heated to 100 °C and then cooled to -100 °C at a rate of 10 °C min -1 . The maximum torque values and angular deflection until fracture of new instruments (n = 10) were measured according to ISO 3630-1. Results were analysed statistically using the Student's t-test at a significance level of P < 0.05., Results: DSC results revealed the absence of martensitic transformation for Reciproc instruments in the temperature range analysed. In both systems, the instruments were composed of a mixture of R-phase and austenite at room temperature. After torsional tests, Reciproc blue had significantly lower values for mean maximum torque at rupture (P < 0.05), although the angular deflection values were significantly higher than the Reciproc classic group (P < 0.05)., Conclusions: Both Reciproc and Reciproc blue instruments were composed of a mixture of R-phase and austenite. Reciproc Blue instruments had a greater angle of rotation to fracture but a lower torque to failure than M-Wire Reciproc instruments., (© 2019 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Purpose: The mechanical properties of orthodontic aligners made from thermoplastic polymers decrease over time in the intraoral milieu. However, there is a lack of information on this topic in the literature. Thus, the elastic properties of polyethylene terephthalate glycol (PETG) aligner films were investigated in vitro under extreme temperature changes simulated by thermocycling, environmental temperature and water absorption., Materials and Methods: A total of 60 specimens made from PETG aligner films (CA Clear Aligner, Scheu Dental, Iserlohn, Germany) were divided into three groups (immersed in distilled water, subjected to accelerated ageing by thermocycling, control). These groups were again divided and tensile testing was performed for all groups at 22 and at 37 °C. Young's modulus (E), 0.2% offset yield strength (R p02 ) and ultimate tensile strength (UTS) were evaluated. Water absorption was determined using an analytical scale., Results: All treated specimens showed water absorption, whereby specimens that were thermocycled absorbed 48% more water than the immersed ones. Young's modulus and UTS were significantly lower for all three groups at 37 °C compared to the corresponding groups tested at 22 °C. Thermocycled and immersed groups showed a significantly lower Young's modulus compared to the control group tested at the same temperature. The mean R p02 was statistically different when comparing the control group tested at 22 °C to the one tested at 37 °C., Conclusions: The results of this study add to the understanding of the clinically well-known degradation of orthodontic aligners during wear time. Extreme alternating temperatures along with warming up to intraoral temperature and water absorption can reduce the material's Young's modulus and may therefore promote a decrease of resulting orthodontic forces.