Recent advances in drug repurposing for dentin repair.

Effect of elevated temperature on strength and microstructure of metakaolin-based geopolymer composites having fireclay and silica sands

This quality improvement project aims to evaluate the perceived benefits among early-career dentists in managing furcal perforations using a simulated clinical environment. The project focuses on the use of 3D printed models with furcal perforation and hydraulic calcium silicate-based cement to repair it, coupled with magnification tools. The project was conducted over 2 years with two cohorts of dental core trainees. Each cohort participated in a half-day program. The session consisted of theoretical training on the causes, prognosis and management of perforations and was followed by hands-on practice, where trainees repaired furcal perforations on 3D printed teeth using hydraulic calcium silicate-based cement. Pre- and post-intervention surveys were administered to assess changes in knowledge, confidence and perceived competence. Trainees reported increased confidence in managing furcal perforations post-training. The use of 3D printed teeth provided a realistic and controlled environment for practice, with the opportunity to use hydraulic calcium silicate-based cement and magnification for effective repairs. Early-career dentists benefit significantly from practical experience in a simulated environment. The combination of theoretical knowledge and hands-on practice using advanced materials and tools improves their competence in managing furcal perforations, potentially leading to better clinical outcomes. This project underscores the importance of simulation-based training in dental education and its role in enhancing procedural skills and confidence among trainees.

Near infrared spectroscopy combined with interval selective ensemble learning for analysis of cement raw meal component contents.

This study evaluated the effects of incorporating a resveratrol-loaded nanoemulsion into a calcium silicate-based cement (MTA) on antioxidant activity, physicochemical properties, apatite formation and bond strength. MTA was modified at 0%, 25%, 50%, 75% and 100%. Antioxidant capacity increased in all nanoemulsion groups (p < 0.05), peaking at 75%. Setting time increased (18.8-26.0 min), with higher values at ≥ 50% (p < 0.05). Solubility increased at ≥ 50%, exceeding 4% (p < 0.05). pH (~9.9) and calcium ion release were higher at 75% and 100% (p < 0.05). FTIR-ATR analysis indicated increased carbonated apatite formation, with lower PO4/CO3 ratios at ≥ 75% (p < 0.05). Compressive strength decreased after 24 h, but not after 30 days. Bond strength increased at 75% and 100% (p < 0.05). Resveratrol nanoemulsion improved apatite formation and bonding; however, higher solubility and reduced early strength require optimization, with 75% as a promising balance.

Highlights-Bacillus subtilis and Bacillus licheniformis increase the compressive strength of cementitious mixes; however, they are susceptive to overdosage, water–cement ratio, and mix homogenization.-Bacillus licheniformis is highly effective to control mortar expansion by sulfate attack.-Bacillus licheniformis creates changes in mixes’ microstructure that control external sulfate attack better than calcium precipitation.-Calcium precipitation is effective in terms of strength, but not in terms of preventing deterioration by sulfate attack in the long term.Bacteria in concrete has been studied as an additive to repair microcracks and reduce permeability, as well as increase compressive strength. Within the broad spectrum of bacteria, two types promise to be effective agents against external sulfate attack: (i) Bacillus subtilis, which could indirectly prevent the entry of sulfates through the mechanism of sealing by calcium precipitation, and (ii) Bacillus licheniformis, which could encapsulate the sulfates that enter by diffusion and prevent the consequences of the pathology, such as expansion and loss of strength. This research evaluates the impact of B. subtilis and B. licheniformis on the performance of cementitious mixes against external sulfate attack, measuring compressive strength, expansion, permeability, and effects on the microstructure. Results show that both bacteria can produce compressive strength improvements of up to 20% at 28 days and 50% at 180 days. Moreover, in the presence of sulfates, improvements of up to 90% can be observed over control mixes. However, this result should be carefully evaluated because although B. licheniformis produces better results in the long term, it results in lower strength in the presence of sulfates in the short term. At the same time, B. licheniformis significantly reduces expansion against external sulfate attack, decreasing it by up to 80%, because it generates less ettringite and gypsum. Thus, B. licheniformis is an effective agent against external sulfate attack. Based on the results, it is estimated that both bacteria can be used to improve performance; however, care must be taken with concentration, which affects homogeneity or generates negative effects. In particular, it is noteworthy that calcium carbonate loss was observed from the mixes due to continuous curing and that calcium precipitation can generate negative effects against sulfates in the long term.

Heavy metal contamination alters soil bacterial community structure around cement factories

Optimised clinical protocol for root canal obturation using single cone and hydraulic cement sealer.

Stress-conditioned permeability evolution and hydro–mechanical coupling in cement-treated clay and sand using low-carbon hydraulic cement

Performance assessment and modelling of CO2 capture via temperature swing adsorption using biowaste-based materials

Abstract In cementing operations for offshore oil and gas wells, the function of the mixing tank is to stir and discharge the cement slurry. However, solid-phase settling is prone to occur in the mixing tank, which affects the cement slurry’s properties, degrades the cementing effect, and increases the risk of blockage. The structural form of the agitator impeller is a key factor determining the uniformity of cement slurry mixing. Taking the integrated mixing and discharge mixing tank of the PCS-521B cementing unit as an example, this paper establishes a Volume of Fluid (VOF) multiphase flow model using Computational Fluid Dynamics (CFD) methods to study the mixing uniformity of four common agitator impellers: double-bend with upper and lower 45° twist (Impeller 1), double-bend with lower 45° twist (Impeller 2), double-straight with upper and lower 45° inclination (Impeller 3), and double-straight with lower 45° inclination (Impeller 4). By analyzing the spatiotemporal distribution of solid-phase volume fraction and the density evolution patterns at the overflow outlet and tank-bottom recirculation outlet, it was found that impellers significantly influence settling behavior. Double-bend impellers resulted in severe solid-phase aggregation (&gt; 30% volume fraction), while double-straight impellers exhibited only minor aggregation. The double-straight impeller with a lower 45° inclination (Impeller 4) maintained a stable overflow density of 1100 kg/m 3 , improving vertical mixing efficiency but still posing a bottom blockage risk. The comprehensive performance ranking of the four impellers is: Impeller 4 &gt; Impeller 3 &gt; Impeller 2 &gt; Impeller 1. The research results can provide a reference for avoiding settling and blockage in cementing mixing tanks and selecting optimal impeller types.

Louis Joseph Vicat’s modest bridge 1812–22 gave rise to modern hydraulic cement. A recently discovered report of its construction reveals the motivation behind Vicat’s life-long research programme. This article is the author’s third study on the work of Louis-Joseph Vicat, a seminal pioneer of material science. The first 1 dealt with Vicat’s unique ability to synthesise analysis and experimentation, and the second 2 with his border-crossing approach to scientific and documentary publication, and this one with the first of only two structures that Vicat built, both of which introduced novel material technologies and led to his further career as a research scientist. The 1812–22 masonry Pont de Souillac discussed here employed Vicat’s artificial hydraulic cement for the first time in one of the pier foundations, and the 1827–29 wire-cable Argentat suspension bridge (demolished in 1892) explored the rust-reducing and binding capabilities of hydraulic mortar. The scientific conclusions that Vicat drew from his experience with both structures fuelled his entire career and prepared the construction field for the development of reinforced concrete.

This in vitro study evaluated the shear bond strength (SBS) between 4 hydraulic calcium silicate-based cements (HCSCs) and 3 intermediate layer materials used in vital pulp therapy (VPT). Two hundred forty specimens were divided into 12 groups and prepared using combinations of HCSCs (mineral trioxide aggregate [MTA], Biodentine, NeoPutty, MTA vital pulp therapy [MTAvpt]) and 3 intermediate layer materials (self-adhesive flowable composite [SAFC], resin-modified glass ionomer [RMGI], and flowable composite [FC]). SBS was measured using a universal testing machine, and failure modes were evaluated under stereomicroscopy. Data were analyzed using two-way ANOVA and Tukey's test with an α=0.05. SBS was affected by HCSC (P < .001), intermediate layer material (P < .001), and their interaction (P=.016). Biodentine exhibited the highest mean SBS (17.24 ± 12.09 MPa), followed by MTAvpt (12.59 ± 10.22 MPa), MTA (11.04 ± 9.80 MPa), and NeoPutty (9.84 ± 10.60 MPa). For intermediate layer materials, SAFC demonstrated the highest mean SBS (21.17 ± 10.88 MPa), significantly greater than FC (13.41 ± 9.07 MPa), and RMGI (3.45 ± 2.52 MPa). The combination Biodentine-SAFC yielded the highest mean SBS value, while groups with RMGI showed the lowest SBS values, with predominantly adhesive failures. Under the conditions of this in vitro study, bond strength between HCSCs and intermediate materials varied according to both material types. SAFC and, in some cases, FC exhibited higher initial adhesion to the tested HCSCs, while RMGI showed consistently low SBS.

Calcium silicate-based cements (CSCs), such as mineral trioxide aggregate, are self-setting hydraulic cements and are among the commonly used endodontic materials due to their suitable sealing ability, marginal adaptation, and bioactivity. In this regard, efforts have been made to develop novel CSCs to improve their properties. Nanotechnology has left a significant impact on all scientific fields, and biomaterials are no exception. The higher surface-to-volume ratio of nanoparticles (NPs) and their cationic charge enhance their antibacterial activity by interacting with anionic bacterial cell surfaces. Incorporating NPs into CSCs can enhance their antibacterial, mechanical, and biological properties. The small size of nanoparticles increases surface area and reactivity, which can improve cement's overall performance, especially in combating bacteria and enhancing sealing. Inspired by the unique properties of nanoparticles, researchers have investigated the effects of incorporating various nanoparticles (e.g., silver NPs, hydroxyapatite NPs, and zinc oxide NPs) into CSCs to enhance their properties. Thus, this review focuses on attempts to improve CSCs by incorporating various nanoparticles. The antibacterial, physicochemical, and biological properties of CSCs after the addition of nanoparticles will be discussed. Further investigations are needed to clarify the unexplored aspects of incorporating nanoparticles into CSCs to enhance the properties of these endodontic materials.

This study evaluated the effects of different endodontic irrigation solutions on the solubility, color alteration, and surface roughness alterations of PD MTA and Biodentine. Cylindrical samples of PD MTA and Biodentine were prepared and subsequently immersed in distilled water, 17% EDTA, 5% NaOCl, 9% HEDP, and 0.2% chitosan nanoparticle solutions for 24 hours. Solubility was determined as the percentage mass loss at 24 h compared to initial values. Color alteration was analyzed using a spectrophotometer (CIE Lab system), and surface roughness (Ra and Sa) was measured with a confocal microscope. Data were statistically analyzed with Kruskal-Wallis, Mann-Whitney U, and Wilcoxon tests at a 5% significance threshold. No significant differences in solubility were observed between PD MTA and Biodentine, but EDTA and chitosan nanoparticles significantly increased solubility compared to other solutions (p<0.05). Biodentine exhibited greater color alteration than PD MTA for all solutions except distilled water (p<0.05), with NaOCl causing the most pronounced color alteration (p<0.05). PD MTA showed higher surface roughness before and after immersion (p<0.05), with HEDP inducing the greatest roughness alterations in both materials (p<0.05). Endodontic irrigants affect the physical properties of hydraulic cements, with varying impacts on solubility, color alteration, and surface roughness. Selecting appropriate irrigation solutions is essential to maintaining material integrity and esthetic outcomes in clinical practice.

The research aims to demonstrate the role of employing cleaner production strategies in improving the environmental performance of industrial economic units through an applied study in the Ard Al- Amara Cement Factory. The study was based on diagnosing the current reality of the factory's operations, which mainly depends on importing semi-manufactured clinkers from abroad. To achieve this, the researcher relied on data from the Ard Al- Amara Cement Factory for the year 2024. Through this, the environmental shortcomings represented in energy consumption and waste, as well as the absence of waste treatment systems, were highlighted. The employment of a re-reduction and re-employment strategy can effectively contribute to raising the efficiency of the factory's environmental performance, reducing the negative impact on the environment, and enhancing sustainability opportunities in the industrial sector. The most important conclusions reached by the research are that adopting cleaner production strategies contribute to reducing operating costs in the long term by reducing waste, improving the efficiency of energy and resource consumption, and eliminating environmental pollutants such as emissions and noise, in addition to reducing the rate of collapses resulting from power outputs, as the cost savings amounted to 7,060,000 dinars (265,320,000 - 258,260,000). By implementing the above proposal, the researcher was able to achieve the environmental dimension of sustainability by reducing fuel costs and periodic maintenance. The research concluded with the necessity of developing awareness and training of employees at the Ardh Al-Amara Cement Factory on the importance of cleaner production strategies and their role in achieving environmental sustainability and reducing operating costs

Micro-CT Assessment of Hydraulic Calcium Silicate Cements for Perforating Internal Resorption in 3D-printed Tooth Replicas at Different Root Thirds: An In Vitro Study.

Mineral trioxide aggregate (MTA) was the first hydraulic cement used in endodontics. It is composed of Portland cement, a binder in concrete, and bismuth oxide to enhance the radiopacity. MTA was introduced in dentistry to be used as a root-end filling material and also to repair root perforations. The specific use was motivated by the well documented hydraulic nature of Portland cement used in construction. Currently, dental hydraulic cements are used for all endodontic procedures. They are composed of a hydraulic cement with various additives and the material chemistry changes when placed in different clinical fields. These characteristics influence the clinical performance of the materials. A classification of hydraulic cements used in dentistry has already been published, but it is unfortunately already outdated due to the rapid changes in the market and material availability. The aim of this publication is to guide the users of hydraulic cements in dentistry in choosing the right material for the clinical technique being undertaken. The new classification being proposed subdivides the components into the cement which is the binder, the radiopacifier, vehicle, and additives. Irrespective of the cement chemistry, the cements are either calcium hydroxide releasing or not, the vehicle is water or alternative, and the additives are cementitious or non-cementitious. This new classification identifies the reaction byproduct as the main classifier of the material type since it is the most significant component that affects the clinical interactions. The presence of water and hydration is important; thus, it is also listed as part of the classification. Alternative vehicles that react with moisture from the environment require updated clinical protocols to ensure the hydration can proceed. The updated classification of hydraulic cement used in dentistry focuses on the clinical effect rather than on the material chemistry; thus, it is more suitable for material identification.

This study aimed to compare the biological performance of a hydraulic calcium silicate cement (EndocemMTA Premixed) containing dimethyl sulphoxide (DMSO), developed to improve handling properties, in comparison with ProRoot mineral trioxide aggregate and Biodentine. Human dental pulp cells were used for in vitro evaluation of cytocompatibility, cell migration and cell-material interactions. Odontogenic differentiation was assessed using a 3D culture model designed to simulate the clinical environment. Pulp capping was performed in vivo on rat maxillary molars, and reparative dentin formation and pulpal inflammatory responses were evaluated using micro-computed tomography (µCT) and histological analyses. In vitro, all investigated materials exhibited comparable cytocompatibility, cell migratory behaviour and odontogenic marker expression, with no significant differences among study groups. The µCT analysis demonstrated significantly greater reparative dentin formation in all experimental groups compared with the control, with Biodentine producing a higher dentin volume than EndocemMTA Premixed. Histological evaluation revealed no significant differences among the experimental groups with respect to pulpal inflammation or dentin bridge continuity. These findings suggest that the incorporation of DMSO into premixed formulations would not adversely affect cytocompatibility or pulp healing. Moreover, the 3D model used in this study might serve as a clinically relevant platform for evaluating pulp-material interactions.

Comparison of five different Light-Cured Pulp Capping Materials to a Hydraulic Calcium Silicate Cement: A Long-Term Physicochemical Study.