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The aim of direct pulp capping (DPC) is to promote pulp healing and mineralized tissue barrier formation by placing a dental biomaterial directly over the exposed pulp. Successful application of this approach avoids the need for further and more extensive treatment. In order to ensure a complete pulp healing with the placement of restorative materials, a mineralized tissue barrier must form to protect the pulp from mi-crobial invasion. The formation of mineralized tissue barrier can only be induced when there is a significant reduction in pulp inflammation and infection. Consequently, promoting the healing of pulp inflammation may provide a favorable therapeutic opportunity to maintain the sustainability of DPC treatment. Mineralized tissue formation was observed as the favorable reaction of exposed pulp tissue against a variety of dental biomaterials utilized for DPC. This observation reveals an intrinsic capacity of pulp tissue for healing. Therefore, this review focuses on the DPC and its healing procedure as well as the materials used for DPC treatment and their mechanisms of action to promote pulpal healing. In addition, the factors that can affect the healing process of DPC, clinical considerations and future perspective has been described.(c) 2023 The Authors. Published by Elsevier Ltd on behalf of The Japanese Association for Dental Science. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/license/by-ac-nd/4.0/).

This clinical study evaluated the antibacterial effects of calcium hydroxide associated with different vehicles during the treatment of infected teeth with apical periodontitis.Bacteriologic samples were taken from 90 necrotic root canals of teeth with apical periodontitis before (S1) and after preparation with a rotary nickel-titanium instrument system and 2.5% sodium hypochlorite irrigation (S2). The teeth were distributed in 3 groups according to the intracanal medication used, which consisted of a calcium hydroxide paste in glycerin, camphorated paramonochlorophenol/glycerin (CHPG), or 2% chlorhexidine for 1 week, and then another sample was taken (S3). The frequency of bacteria-positive cases and the reduction of bacterial counts were evaluated by quantitative real-time polymerase chain reaction.Substantial intracanal bacterial reduction was observed after preparation in the 3 groups (P .001). After calcium hydroxide paste in glycerin medication, the number of bacteria-positive cases decreased from 20/29 (69%) to 17/29 (59%); however, the mean bacterial counts increased 8.4% from S2 to S3. Medication with CHPG reduced the number of bacteria-positive cases from 17/29 (59%) to 15/29 (52%), with a significant mean S2-S3 reduction of 71% (P .05). In the chlorhexidine group, the number of bacteria-positive cases decreased from 21/30 (70%) to 17/30 (57%) after medication, with a mean S2-S3 reduction of 55%, which, however, was not statistically significant (P .05). Intergroup comparisons showed no significant differences (P .05).Comparison between the 3 calcium hydroxide pastes showed no significant differences in antibacterial effectiveness in the main root canal. However, only the CHPG paste showed a significant reduction in bacterial counts when postpreparation and postmedication samples were compared.

Microsatellite unstable (MSI) colorectal cancers (CRCs) are due to DNA mismatch repair (MMR) deficiency and occurs in15% of non-metastatic diseases and 5% in the metastatic setting. Nearly 30% of MSI CRCs occur in a context of constitutional mutation of the MMR system (Lynch syndrome). Others are sporadic cancers linked to a hypermethylation of the MLH-1 promoter. The pathogenic alterations of MMR genes lead to the accumulation of frequent somatic mutational events and these tumours arbour a high antigen burden and are highly infiltrated with cytotoxic T-cell lymphocytes. Microsatellite instability/DNA mismatch repair deficiency (MSI/dMMR) status has prognostic and predictive implications in non-metastatic and metastatic CRCs. The prognostic value of MSI status in non-metastatic CRCs has been studied extensively, yet the data are more limited for its predictive value in terms of adjuvant chemotherapy efficacy. In both cases (metastatic and non-metastatic settings) treatment with immune check-point inhibitors (ICIs) have shown a remarkable effectiveness in the context of MSI/dMMR status. Indeed, recent data from prospective cohorts and randomised trials have shown a dramatical improvement of survival with immunotherapy (programmed death-ligand 1 [PD-(L)1] cytotoxic T-lymphocyte-associated antigen 4 [CTLA-4] blockage) in metastatic or non-metastatic MSI/dMMR CRC. In this review we report and discuss how and for whom to test for the MSI/dMMR phenotype, as well as the prognostic value of this phenotype and the new treatment recommendations options for this unique CRC population. Despite their efficacy, primary and secondary resistance to immune checkpoint inhibitors (ICIs) are observed in more than 50% MSI-H/dMMR CRC patients and in the future how to identify these patients and to overcome resistance will be an important challenge.

This study aimed to determine the most effective antibiofilm concentration of silver nanoparticles (AgNPs) alone or in combination with calcium hydroxide (Ca[OH]The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of AgNPs alone or with Ca(OH)The MIC and MBC of AgNPs alone against F. nucleatum coincided at 0.04%. The combination of AgNPs + Ca(OH)The findings demonstrated that combining AgNPs with Ca(OH)

Introduction: This Consolidated Standards of Reporting Trials randomized clinical trial investigated T helper (Th1, Th2, Th9, Th17, and Tfh) and regulatory T (Treg) cell–type cytokines and their networks in apical periodontitis (AP). We also assessed the effects of calcium hydroxide [Ca(OH)2] intracanal medications (ICMs) on helper T and Treg cell–type cytokines. Methods: Twenty teeth with primary endodontic infection and apical periodontitis were randomly divided into two groups: Ca(OH)2 + saline solution (n = 10) and Ca (OH)2 + 2% chlorhexidine-gel (n = 10). Samples were collected from the periradicular tissue fluid (PTF) before (PTFs1) and after 14 days of ICMs (PTFs2). The Human High Sensitivity T Cell Panel was used to quantify target T-helper (Th)1: interelukin (IL)-2, IL-12, and interferon-gamma (IFN-γ); Th2: IL-4, IL-5, and IL-13; Th9: IL-9; Th17: IL-17; T follicular helper cells (Tfh): IL-21; and Treg-cell-type cytokine: IL-10. Results: Th1-type cytokines were higher than Th2-type ones, at PTFs1. Positive (+) associations were found among all Th1-type cytokines and all Th2-type cytokines. There were negative (-) correlations between all Th1- and Th2-type cytokines. Size of radiolucent lesions and symptoms (tenderness to percussion and/or pain on palpation) were positively correlated with Th1-type cytokines, IL-17, and IL-21 but negatively correlated with Th2-type cytokines and IL-10 (all, P .05). Conclusions: Complex T-cell cytokine networks are involved in AP. Both Ca(OH)2 ICMs effectively increased IL-4, IL-5, IL-10, and IL-13 and lowered IL-2, IL-12, IL-17, IL-21, and IFN-γ.

At present, the cyanide gold extraction process is still the main technology for gold production. Generated cyanide tailings containing highly toxic substances exhibit potential environmental risks. These tailings are in urgent need of purification treatment, especially after being classified as hazardous waste. In this study, the impacts of elution methods, operating time, tailings/water ratios, reagent types on the elution rates of cyanide were investigated. Furthermore, the composite elution method developed in this research was extended for engineering. Results showed that the optimum elution conditions were determined to be: stirring elution, tailings/water ratio (M/V; 1:1) and operating time (10-20 min). Besides, 4 reagents (sodium dodecyl benzene sulfonate, cyclodextrin, sodium silicate and calcium hydroxide) were selected from four categories of 21 reagents for further composite elution. The cyanide elution rate was the highest (90.7%±0.1%) while the molar ratio of these 4 reagents was 5:2:2:1. Moreover, the combination of reagent elution and positive pressure filtration improved the elution efficiency of cyanide (92.6%±0.8%). And the cyanide content in the toxic leaching solution was lower than the standard value (5.0 mg/L). Furthermore, the composite elution method developed in this study was also extended for engineering. The concentration of cyanide in the leachate was5.0 mg/L, and was stable during 189 days of detection. Notably, the effluent can be reused directly, or reused after further treatment. The zero discharge of effluents and solid wastes was realized in the processes. The above results provided supports for the engineering treatment of cyanide tailings.

Frescoes were developed as religious paintings in medieval Europe before the rise of oil paintings. When coloring with natural pigments on a slaked lime plaster, calcium carbonate gradually forms a coating on the pigments at the surface of the plaster over a period of decades to a hundred years. Many frescoes have been maintained for hundreds of years and have become part of historic heritage. However, the making of frescoes is rarely selected as a general art painting method because it takes a lot of time for complete carbonation to occur. This study demonstrated that a geomimetic ceramic hardening technique using calcium hydroxide and calcium carbonate, followed by subsequent acceleration of carbonation at the surface of the calcium hydroxide with supercritical carbon dioxide, could assist in forming frescoes in a short time. The immobilization of the pigment used on the base calcium hydroxide body was evaluated by a scratch test with emery paper, and pigment color differences were measured by a colorimeter. Furthermore, the micromorphology of the resultant frescoes fabricated by the geomimetic technique in a short time was investigated to evaluate the progress of carbonation. As a result, frescoes could be fabricated in a short time by combining a geomimetic technique and carbonation with supercritical carbon dioxide using a novel pigment that is a mixture of pigment and calcium hydroxide. The pigment in the final sample was completely fixed to the base calcium hydroxide body, and the pigment color was brighter than the original pigment color due to the densification of calcium carbonate after supercritical carbon dioxide treatment.

Metastable vaterite blocks are expected to show high reactivity. However, they have not been reported to date. In this study, the feasibility of fabricating an artificial vaterite block was investigated by exposing a Ca(OH)2 compact to CO2 under several conditions. Under a 100% H2O atmosphere, a calcite block was formed within three days. Under a 100% methanol atmosphere, no carbonation was observed for seven days. Under 90% methanol without atmospheric flow, a vaterite block containing 5 mass% of unreacted Ca(OH)2 and 3 mass% of calcite was formed after 24 h. On day 7, it was transformed into a block with 70 mass% of calcite, 27 mass% of vaterite, and 3 mass% of unreacted Ca(OH)2. By contrast, under 90% methanol with atmospheric flow to remove the accumulated H2O in the compact, a pure CaCO3 block of 98 mass% vaterite and 2 mass% calcite was formed on day 3. Therefore, the regulation of the amount of H2O is important for fabricating vaterite blocks. Porosimetry measurements revealed that the calcite block fabricated under 90% methanol without atmospheric flow demonstrated a pore size profile closer to that of the vaterite block than that of the calcite block fabricated under 100% H2O atmosphere because the vaterite with small spherical crystals was formed initially before its transformation to calcite.

To efficiently remove high concentrations of hexavalent chromium (Cr(VI)), calcium–aluminum-layered double hydroxide (CaAl-LDH, denoted as CAL), and polypyrrole-modified CAL (CAL-PPy) were prepared by hydrothermal and in situ polymerization methods, respectively. The chemical structure, morphology, and elemental results indicated that the chain-like polypyrrole was decorated with hexagonal CAL. The specific surface area of CAL-PPy increased from 8.746 m2/g to 24.24 m2/g. The adsorption performances of CAL and CAL-PPy for aqueous Cr(VI) were investigated using batch equilibrium experiments. The decontamination process of aqueous Cr(VI) (100 mg/L) reached the equilibrium state within 50 min, and the kinetic data met the pseudo-second-order kinetic equation. The Langmuir model described the isothermal data properly, and the obtained theoretical adsorption capacity of CAL for Cr(VI) at 318 K was 34.06 mg/g, while that of CAL-PPy was 66.14 mg/g. The removal mechanisms involved electrostatic attraction, surface complexation, anion exchange, and reduction to low-toxicity Cr(III). Therefore, CAL and CAL-PPy have underlying applications in treating real wastewater containing Cr(VI).

Introduction Calcium hydroxide has been used successfully in root canal therapy for many years. However, it can cause serious damage if it is inadvertently displaced into surrounding vital structures, resulting in thrombosis if displaced into blood vessels, damaging connective tissue, and causing skin necrosis. These adverse reactions are known as Nicolau Syndrome (NS) or embolia cutis medicamentosa. Very few case reports have been published about these adverse effects of injecting calcium hydroxide beyond the apex during root canal therapy. Methods A 16-year-old female patient was referred to the Endodontic Department, Hamad Dental Center (HDC) for assessment following treatment by the Maxillofacial Surgery Department for a swelling and tissue necrosis that occurred after endodontic treatment in another clinic. Results When the patient initially attended the Maxillofacial Surgery Department, she presented with swelling on the left side in the region of the maxillary left first permanent molar. On examination, there was a change in the colour of the skin of the left cheek in that area along with some reported paralysis of the left side of her lips. Analgesics and antibiotics had already been prescribed at the referring clinic. Two weeks later, the patient developed a necrotic patch of skin on the same area. Subsequent evaluation at the Endodontic Department of HDC led to a diagnosis of NS. Conclusion Nicolau syndrome is a very rare iatrogenic condition. Displacing calcium hydroxide beyond the apex might increase the chance of NS. Clinicians should avoid over-instrumentation and forced injection of calcium hydroxide to prevent NS.

Hypothesis The mechanism of calcium silicate hydrate (CSH) formation, a relevant component of cement, the largest used material by mankind, is well documented. However, the effects of nano-sized materials on the CSH formation have not yet been evaluated. To this aim, a kinetic study on CSH formation via the “pozzolanic reaction” of nanosilica and calcium hydroxide nanoparticles, and in the presence of hydroxypropyl cellulose (HPC) as hydration regulator, is reported in this paper. Experiments The reagents were mixed with water and cured at 10, 20, 30 and 40 °C. The reaction kinetics was studied with differential scanning calorimetry (DSC). A Boundary Nucleation and Growth model (BNGM) combined with a diffusion-limited model was used to analyze the data, yielding induction times, reaction rates, activation energies, nucleation and linear growth rates, and the related diffusion coefficients. Findings The rate constants kB and kG, which are, respectively, the rate at which the nucleated boundary area transforms, and the rate at which the non-nucleated grains between the boundaries transform, increase with temperature. Their different temperature dependence accounts for the prevailing effect of nucleation over nuclei growth at progressively lower temperatures. The nucleation rate, IB, is strongly enhanced when using nanomaterials, while the linear growth rate, G, is limited by the tightly packed structure of the transforming matrix. HPC influences the kinetics between 10 and 30 °C; at 40 °C the temperature effect becomes predominant. HPC delays induction and acceleration periods, increases Ea(kB), and enhances the reaction efficiency during the diffusion regime, by retaining and delivering water over the matrix, thus allowing a higher water consumption in the hydration reaction of CSH.

The evaluation of nano-priming effect with galactomannan stabilized Phyto-complexed calcium hydroxide (Ca(OH)2), selenium oxyanion‑calcium hydroxide SeO-(Ca(OH)2), and selenium‑calcium hydroxide Se-(Ca(OH)2) nanocomposites was carried out in Vigna radiata (Green gram) seeds. The green source Cassia angustifolia seed rich in galactomannan and other phytoconstituents was detected experimentally and characterized with GC–MS, UV, FT-IR, NMR, XRD, and SEM studies. The highly active galactomannan and other biomolecules, enable their terminal oxygen and hydroxide groups to bind with calcium and selenium ions through bidentate and monodentate chelation, followed by bio-reduction. On the mild-thermal agitation, bio-stabilized (Ca(OH)2), SeO-(Ca(OH)2), and Se-(Ca(OH)2) nanocomposite coated with seed-derived biomolecules were precipitated under an alkaline condition. The size and morphological parameters of bio-fabricated nanocomposites were characterized to exhibit the spherical and hexagonal shape in nanoscale images of size 17.9 nm for (Ca(OH)2), 56.2 nm for SeO-(Ca(OH)2), and 69.3 nm Se-(Ca(OH)2). The sub-standard seed lot of Vigna radiata (Green gram) seeds (71%) was examined using synthesized nanocomposites at various concentrations, and the obtained physiological parameters in seedlings were compared with hydro-primed seeds. The nano-priming action of all the Phyto-complexed nanocomposites was predicted with a positive response, where the porous Se-(Ca(OH)2) possess high efficacy interaction on seed embryos and beneficially results at 90% germination.

The rapid growth of population with increased facilities for comfort nowadays leads to a drastic depletion of natural resources. The present work emphasizes the re-refining process of waste lubricating oil by the solvent-extraction flocculation process. Re-refining is considered by many as a preferred option in conserving resources, minimizing waste, and reducing environmental hazards to a great extent. The effect of various parameters like refining time, refining temperature, solvent to waste oil ratio, flocculant dosage, adsorbent to distilled oil ratio has been elaborately studied, and the optimum yield percent was obtained at 33 °C of refining temperature, 20 min of refining time with a solvent to waste oil ratio of 5:1 (w/w). Various solvents like iso-butanol and n-butanol were used, and iso-butanol was found to produce a higher yield of 72%, which is 2% higher than the solvent n-butanol. Calcium hydroxide was used as a flocculant, and a concentration of 2 kg of flocculant per kg of solvent was optimum. The flashpoint, ash content, and viscosity index of re-refined oil were 210 °C, 0.25 g, and 175, respectively, comparable to virgin lube oil. The purity and the existence of oxidation products were elaborately analyzed by FTIR and GC–MS analysis. Thus, the refined oil obtained can effectively mitigate the ever-growing oil crisis and help create a healthy and pollution-free environment.

The accelerated chemical-industry has caused a rapid increase of calcium-containing alkali wastes, containing a large amount of calcium, magnesium, aluminum, and iron ions and caused a great risk to environment. Anaerobic digestion or dark fermentation is one of the most promising technologies to recover biogas, such as methane and hydrogen. Nevertheless, the hydrolysis processes of lignocellulosic biomass and waste activated sludge were the rate-limiting step of the biochemical reactions, which focused on pretreatment to improve the biodegradability of substrate. In addition, when some easily acidified wastes, such as kitchen residue, fruit and vegetable waste, and high concentration organic wastewater, are used as substrate to produce hydrogen and methane, volatile fatty acid accumulation often occurs, causing the process instability. Thus, this paper reviewed the main roles of calcium-based alkali materials such as calcium oxide, calcium peroxide and calcium hydroxide on the substrate pretreatment for obtaining high biodegradability, while others (e.g. calcium carbonate, lime and red muds) used as additives for maintaining process stability, thereby increasing biogas yield from anaerobic digestion and dark fermentation.

Introduction More data are needed before affirming that single-visit approaches are effective and safe for regenerative endodontic procedures (REPs). This study compared clinical and radiographic outcomes of REPs between interappointment dressing or single-visit protocols. Methods Twenty young patients presenting traumatized immature teeth with pulp necrosis were divided into 2 groups. Teeth were submitted to 6% sodium hypochlorite and 2% chlorhexidine irrigation and to 17% EDTA use before blood clot induction. In the interappointment dressing group (n = 11), calcium hydroxide was used with 2% chlorhexidine gel for 21 days before scaffold induction. In the single-visit group (n = 9), the scaffold was induced during the only appointment. Patients were followed up for 24 months. Primary, secondary, and tertiary outcomes were assessed by 3 independent evaluators. Preoperative and follow-up radiographs were assessed for quantitative measurements of the apical diameter, root width, root length, and cervical barrier placement and compared between groups using the t test or Mann-Whitney U test. Categoric variables were assessed with the G test and the Fisher exact test and continuous variables with the Mann-Whitney U test. Statistical significance was set at 5%. Results One tooth showed persistence of infection. No difference was observed in cervical barrier placement (P > .05); between groups regarding primary, secondary, and tertiary outcomes (P > .05); and in parameters of quantitative radiographic outcomes (P > .05). Conclusions Completing REPs with an interappointment dressing or a single-visit protocol presented similar clinical and radiographic outcomes. A single-visit protocol of REPs using 6% sodium hypochlorite, 2% chlorhexidine, and 17% EDTA permitted satisfactory outcomes in necrotic immature permanent teeth.

Although epigallocatechin-3-gallate (EGCG) from green tea has been successfully used in the prevention and treatment of several infectious and immunoinflammatory diseases because of its proven anti-inflammatory, antioxidant, antimicrobial, and antiresorptive role, its use as an intracanal dressing has not been proposed. The aim of this study was to develop a formulation based on EGCG for endodontic use by assessing its physicochemical and biological properties.Initially, physicochemical characterization of EGCG was performed by ultraviolet-visible and fluorescence spectroscopy to evaluate if the properties were maintained in acidic pH and time (1-6, 24, and 27 hours). After that, biological studies evaluated the developed formulation of EGCG at different concentrations (1.25, 5, 10, and 20 mg/mL). The tissue compatibility with subcutaneous tissue of mice was evaluated by plasma leakage after 24 hours and the examination of macroscopic and microscopic features at 7, 21, and 63 days after the insertion of polyethylene tubes containing the formulations. The repair of experimentally induced periapical lesions in dog's teeth by radiographic and histopathologic analysis was also evaluated. The scores were statistically analyzed by the chi-square and Fisher exact test. Analysis of variance followed by the Tukey posttest were used for the quantitative analysis. The significance level was 5%.The physicochemical characterization performed under ultraviolet-visible spectrophotometry showed that the EGCG properties remained unaltered in acid pH and function of time, keeping its wavelength to 274 nm. Macroscopic parameters evaluated at 7, 21, and 63 days showed that all concentrations presented no epithelial ulceration or presence of mild superficial tissue necrosis, edema, or vascularization with no significant difference in the control group. During all periods of microscopic examination, all groups presented the absence of abscess foci and edema and the presence of fibrous capsule and neovascularization. The presence of reparative tissue with a gentle presence of neutrophilic inflammatory cells was also observed for all groups, except for the calcium hydroxide paste group, which presented a more pronounced inflammation and tissue necrosis at days 7 and 21 (P .001). At day 63, all groups presented an absence of inflammatory infiltrate and necrosis. The evaluation of dog teeth showed that treatment with the EGCG formulation provided a reduction of the periapical radiolucent area and allowed the repair of apical and periapical tissues (P .05).The developed formulation based on EGCG from green tea presented physicochemical stability and tissue compatibility and provided the repair of periapical lesions when used as an intracanal dressing.

In this study, lime (calcium hydroxide) treatment (LT) was applied as an alkaline pretreatment subsequent to hydrothermal treatment (HT) in terms of fermentable sugar and bioethanol production from acacia wood. To maximize the hydrolysis of cellulose and hemicellulose, the condition of 200 °C for 10 min of HT was selected for subsequent lime treatment. The optimum conditions of LT were established to be a ratio of calcium hydroxide to hydrothermally treated acacia biomass of 12.2%, temperature of 70.9 °C, and reaction time of 23.5 h using a response surface methodology, and the maximum glucose yield by prediction and experiment were determined to be 74.4% and 73.5%, respectively. Further mechanical refining accelerated the access of the enzyme to glucan, resulting in an increase in glucose conversion (80.5%). Although the glucose yield by LT was 21.5% higher than that of HT, the ethanol yield was 33.5% lower due to the negative effect of residual calcium ions on yeast fermentation.

Organic dye-containing wastewater has become an increasingly serious environmental problem due to the rapid development of the printing and dyeing industry. Hydrogel is a promising adsorbent for organic dyes because of its unique three-dimension network structure and versatile functional groups. Though many efforts have been made in hydrogel adsorbents recently, there is still a critical challenge to fabricate hydrogel adsorbent with high adsorption capacity and high efficiency at the same time. To address this concern, we developed a calcium hydroxide nano-spherulites/poly(acrylic acid -[2-(Methacryloxy)ethyl]trimethyl ammonium chloride) hydrogel adsorbent with novel villi-like structure. The hydrogels were prepared through a simple free radical copolymerization method using calcium hydroxide nano-spherulites as crosslinker. The resultant hydrogel adsorbents showed a maximum adsorption capacity of 2249 mg/g in a 400 mg/L methylene blue solution and a high removal ratio of 98% in 1 h for a 50 mg/L methylene blue solution. In addition, the adsorption behaviors of our hydrogel adsorbents could be well described by pseudo-second-order kinetic model and Langmuir adsorption isotherm model. Furthermore, this kind of hydrogel adsorbent showed selective adsorption behavior for methylene blue. Altogether, the hydrogel adsorbent developed in this work has a high capacity and high efficiency in organic dye removing and promised a great potential in wastewater treatment application.

Pulp-capping materials are commonly adopted in the clinic to form reparative dentin and thus protect dental pulp tissues from cases of deep caries, accidentally exposed pulps or partial pulpotomy. Some traditional pulp capping materials used in the clinic include calcium hydroxide and mineral trioxide aggregates. However, there are limitations to thin restorative dentin, and a long period of time is needed to cause degenerative changes in dental pulp. In this paper, injectable colloidal gels were developed to induce the formation of reparative dentin through a simple UV method from methacrylic acid functionalized gelatin loaded with notoginsenoside R1 (Gel-MA/NGR1). The results of the physicochemical property examinations showed that the prepared Gel-MA/NGR1 hydrogel possessed an appropriate interconnected porous microarchitecture with a pore size of 10.5 micrometres and suitable mechanical properties with a modulus of 50-60 kPa, enabling cell adhesion and proliferation. The hydrogel remained hydrophilic with sustained drug release performance. In addition, Gel-MA/NGR1 significantly enhanced the odontogenetic differentiation of mouse dental papilla cells by elevating the expression levels of the dentinogenic markers ALP and OCN and extracellular matrix mineralization. In vivo stimulation was carried out by injecting the precursors into the predrilled alveolar cavity of Sprague-Dawley rats followed by immediate in situ UV crosslinking. The results showed that Gel-MA/NGR1 has a strong capacity to promote reparative dentin formation. Haematoxylin& eosin, Masson, and immunohistochemical staining (DMP-1, DSPP, OCN and RUNX2) and micro-CT were employed to illustrate the effectiveness of dentinogenesis, and the relative volumes of calcification were found to have increased ~175-fold. All of the results showed that the Gel-MA/NGR1 hydrogel promoted reparative dentin formation, which suggests that this hydrogel provides great potential as a pulp-capping material to induce dentin formation.

Intelligent packaging that provides real-time information on food quality is useful for consumers. We developed a kimchi ripening indicator that can determine the ripeness of kimchi inside packaging and evaluated its applicability and limitations. The indicator was made using calcium hydroxide, which captures CO

This paper inspects the impact of MK and SF on the mechanical properties of concrete. In this study the replacement percentage of cement with Meta-kaolin was ranged from (7–8%) and the addition of silica fume by (15%). The results showed that the obtained compressive strengths, split tensile strengths and flexural strengths for the concrete have been determined that all results of the tests have been increased while increasing the meta kaolin ratio up to 7%. later there is a little decreasing in the strength for overflowing use of meta kaolin up to 7.5% and 8% which decreases the ratio of w/c and postponement the activity of a pozzolan. The maximum value of strength with the 7% ratio of meta kaolin addition is sufficient because the meta kaolin amount reacts with the calcium hydroxide which speeds up the hydration of cement and creates gel of C-SH. From the results the best percentage of Meta-kaolin can be replaced with cement is (7%) with addition of silica fume by (15%).

Dental caries is an infectious multifactorial disease. Biomimetic remineralisation of non-infected carious dentine helps in retaining tissues to a maximum degree during vital pulp treatment. However micro gaps and residual bacteria below restorations lead to microleakage, degradation of tooth structure and secondary caries. Remineralizing agent with anti-bacterial efficacy would help contain secondary caries and its sequelae. The aim of the study was to evaluate the antimicrobial activity of remineralizing paste containing Strontium doped Nano hydroxyapatite (Sr-nHAp) with Non Collagenous Protein (NCP) analogue, Chitosan. In this study dentin slabs, 200 µm thick obtained from freshly extracted premolars were demineralised and inoculated with Streptococcus mutans to simulate artificial carious lesion. The specimens were divided in to six groups based on the reminerlising regimen, Group 1–10 wt%Sr-nHAp, Group 2–20 wt%Sr-nHAp, Group 3–10 wt%Sr-nHAp + Chitosan and Group 4–20 wt%Sr-nHAp + Chitosan, Group 5 Positive control – Calcium hydroxide and Group 6, negative control, no treatment. The dentin specimens were homogenised and assessment of bactericidal effects was done by counting the number of viable bacteria after 48 h of incubation. Agar well diffusion test was performed to measure the zone of inhibition. Results were tabulated and analysed statistically using, ANOVA and Post – hoc Bonferroni tests (P = 0.05). All experimental groups except Group 1, exhibited antibacterial properties observed by Zone of Inhibition and reduced colony forming units. Antibacterial efficacy of the remineralizing paste was enhanced by the addition of Chitosan and its antimicrobial efficacy was comparable to calcium hydroxide.

Precipitation of calcium deficient hydroxyapatite nanoparticles in an environmentally benign manner by using only dilute solutions of calcium hydroxide and phosphoric acid without pH adjustment and addition of other chemicals, and water, being the only by-product was investigated by using continuous flow Vortex Reactor (VR) and Semi-Batch Reactor (SBR). The effect of hydrodynamics by changing the Reynolds number of the jets providing residence times of 8.4 ms to 4.37 s for VR, and by changing the stirrer speed between 100 rpm (Re = 2656) and 1000 rpm (Re = 26560) for SBR, on the particle size, particle size distribution, and morphology of the particles was investigated for both systems. It has been shown that it is possible to produce pure phase hydroxyapatite nanoparticles in the desired morphology by changing production system, without resorting to additives. While VR produced rod-like particles with the crystallite size around 4 nm, SBR produced spherical particles with the crystallite size of around 5 nm.

The purpose of this study was to evaluate the cleanliness of root canal walls and dentinal tubules after attempting to remove the calcium hydroxide dressing with different irrigant solutions and the use of nonactivated irrigation or passive ultrasonic irrigation (PUI).After root canal instrumentation, 80 single-rooted teeth were filled with calcium hydroxide mixed with propylene glycol and 0.1% rhodamine B dye and inserted into canals with a Lentulo spiral. The calcium hydroxide dressing was initially removed with 10 mL saline solution and reinstrumentation with the master apical file. Then, the samples were randomly assigned into 8 experimental groups (n = 10) according to the irrigant solution with or without PUI: 2.5% sodium hypochlorite, 17% ethylenediaminetetraacetic acid + 1.25% sodium lauryl ether sulfate (EDTA-T), 37% phosphoric acid, or 70% ethanol. A final flush with 5 mL saline solution was performed. The percentage of clean root canal walls and the depth of clean dentinal tubules were measured with images of confocal laser scanning microscopy. The groups were compared using the 2-way analysis of variance test with the Bonferroni post hoc test for depth analysis and the Kruskal-Wallis with Dunn post hoc test for the perimeter analysis.Irrigation with 70% ethanol presented a significantly higher percentage of clean root canal walls and a higher depth of clean dentinal tubules when compared with irrigation with 2.5% sodium hypochlorite and 17% EDTA-T for both irrigation methods (P.05). No differences were observed between nonactivated irrigation or PUI protocols (P.05).Seventy percent ethanol enhanced calcium hydroxide removal from the apical root third compared with 2.5% sodium hypochlorite or 17% EDTA-T.

Natrium Hydroxide (NaOH) and Calcium Hydroxide (Ca(OH)2) as an absorbent was used in the filtration system of the mobile anaerobic digester (AD) to improve the quality of biogas from dairy cattle manure. Twelve pilots insulated of mobile AD used in this study. The average temperature inside the digester was 28.37 °C, and in the outer digester 27.16 °C. The average biogas temperature before filtration was 28.37 °C, and after filtration 31.09 °C. The biogas filtration using adsorbent was a very significantly effect (P 0.05). The average biogas production using NaOH was 717.50 mL h−1, Ca(OH)2 715.63 mL h−1, and control 676.25 mL h−1. The adsorbent treatments were very significantly effects (P 0.05) among the type of adsorbent. The NaOH could increase the percentage of methane (CH4) (14.26 %) and oxygen (O2) (22.06 %) content, and reduced carbon dioxide (CO2) (30.86 %) compared with control. However, Ca(OH)2 adsorbent could increase CH4 (7.77 %) and O2(11.22 %) and reduced CO2 (17.88 %). The mobile anaerobic digester is suitable for smallholder farmer because more simple and cheaper.

Isoconversional methods combined with thermogravimetry were applied to investigate the decomposition kinetics of bastnaesite concentrates with different amounts of calcium hydroxide added. The apparent activation energy was calculated, and the results indicate that the overall reaction involves more than one single step. The reaction with a lower content ( 15 wt%) involves another step which denotes the decomposition of newly formed calcium carbonate during roasting. The activation energy increases with increasing amount of calcium hydroxide in the lower range (0–15 wt%). This is due to the resistance of calcium hydroxide to heat and mass transport. However, more calcium can promote the decomposition reaction more effectively and thus reduce the activation energy. Nonlinear fitting was performed by fitting the experimental data to Avrami-Erofeev model to determine the reaction model and pre-exponential factor. The theoretical models were proven to be reliable for kinetic prediction.

To provide basic research into the utilization of mine tailings as supplementary cementitious materials in cement, the pozzolanic activity and hydration properties of quartz-a common mineral phase in mine tailings-after undergoing mechanical grinding were investigated. In this study, a supplementary cementitious material was obtained using the mechanical grinding of quartz. Prolonged grinding resulted in a gradual increase in the pozzolanic activity index and percentage of dissolution in an alkaline solution, as well as a reduction of the relative crystallinity. The particle size appeared to have reached a limit after 80 min of grinding; however, the specific surface area reached its limit after 120 min of grinding, which was mainly due to the continual increase in pore volume of the micropores and mesopores from the grinding process. As an active supplementary cementitious material, the hydration product of ground quartz was an amorphous C-S-H gel in the presence of calcium hydroxide. This study provides a research basis for investigating the pozzolanic activity and hydration properties of ground quartz, which is beneficial to an evaluation of the pozzolanic activity of siliceous mine tailings after mechanical activation.

Introduction The aim of this study was to evaluate the antibiofilm effectiveness of calcium hydroxide (Ca[OH]2) mixed with 0.02% silver nanoparticles (AgNPs) in comparison with 1 mg/mL triple antibiotic paste (TAP), Ca(OH)2, and 0.02% AgNPs against Enterococcus faecalis using confocal laser scanning microscopy. Methods Ninety dentin disks were prepared, sterilized, and inoculated with E. faecalis to establish a 3-week-old biofilm model. The samples received 1 mg/mL TAP, a mixture of Ca(OH)2 + 0.02% AgNPs, Ca(OH)2, or 0.02% AgNPs (n = 20/group). Specimens in each group were equally subdivided into 2 groups and incubated for 2 and 4 weeks. Untreated dentin disks (n = 10) were exposed to sterile saline solution and acted as a positive control. Sterile dentin disks (n = 10) were incubated anaerobically in brain-heart infusion broth and served as a negative control. At the end of each observation period, the specimens were stained with LIVE/DEAD BacLight dye (Molecular Probes, Eugene, OR) and analyzed with confocal laser scanning microscopy to determine the proportion of dead cells in the biofilm. Statistical analysis was performed using the generalized linear model repeated measure and Tukey tests (P Results A significantly greater proportion of dead cells was observed in the samples treated with 1 mg/mL TAP (90.39% and 99.41%) and a mixture of Ca(OH)2 + AgNPs (90.85% and 98.49%) than those in the samples treated with Ca(OH)2 (76.14% and 91.71%) and AgNPs (62.83% and 88.07%) at 2 and 4 weeks, respectively. A significant difference in the antibiofilm effectiveness was observed among the groups (P .05). All medicaments showed a significant difference in antibiofilm efficacy at the 2 time points. Conclusions The mixture of Ca(OH)2 + AgNPs showed a high antibiofilm effect and was not significantly different from 1 mg/mL TAP. Furthermore, long-term contact between intracanal medicaments and bacterial cells achieved significant antibiofilm efficacy.

This research is co-financed by Greece and the European Union (European Social Fund- ESF) through the Operational Programme «Human Resources Development, Education and Lifelong Learning» in the context of the project “Strengthening Human Resources Research Potential via Doctorate Research” (MIS-5000432), implemented by the State Scholarships Foundation (IKY). Η έρευνα συγχρηματοδοτείται από την Ελλάδα και την Ευρωπαϊκή Ένωση (Ευρωπαϊκό Κοινωνικό Ταμείο - ΕΚΤ) στα πλαίσια του Επιχειρησιακού Προγράμματος «Ανάπτυξη Ανθρώπινου Δυναμικού, Εκπαίδευση και Δια βίου Μάθηση» Πράξη «Ενίσχυση του ανθρώπινου ερευνητικού δυναμικού μέσω της υλοποίησης διδακτορικής έρευνας» (MIS 5000432), που υλοποιήθηκε από το Ίδρυμα Κρατικών Υποτροφιών (IKY). Summarization: This paper studies the morphological characteristics of calcium hydroxide nanoparticles in water based dispersions, produced following the main bottom-up (CaCl2/NaOH replacement reaction) and top-down methodologies. The work focuses on the effect of three different surfactants (TritonX-100, n-octylamine and amylamine) on the morphological characteristics of the resulting Ca(OH)2 nanoparticles and compares them with the ones produced in a mixture of water and 2-propanol. Moreover, in an attempt to approach the compatibility enhancement with siliceous stones, a calcium hydroxide—TEOS composite was also studied. The morphological, chemical and the mineralogical characterization of the nanoparticles produced were carried out by electron microscopy (SEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). It is shown that the modifications induced by the production methodologies limited the agglomeration phenomena and altered the morphological characteristics of nanoparticles, when compared to the results obtained by the original bottom-up method, resulting in the synthesis of hexagonal, plate-like, rounded and angular portlandite nanoparticles. The size range of the nanoparticles extended from 60 to 350 nm. Presented on: Journal of Cultural Heritage

This study aimed to evaluate (1) the effect of irrigating solutions and intracanal medicaments on the release of transforming growth factor beta 1 (TGF-β1) and vascular endothelial growth factor (VEGF) from cervical root dentin and (2) the effect of associating triple antibiotic paste (TAP) and calcium hydroxide paste (CH) with 2% chlorhexidine (CHX) on TGF-β1 release.First, 119 specimens from roots (cervical thirds) were obtained and were distributed into 5 groups: 2% CHX, 2.5% sodium hypochlorite, TAP, CH, and 10% EDTA by each growth factor (TGF-β1 [n = 8] and VEGF [n = 8]). Then, specimens were distributed as follows (n = 13): TAP + 2% CHX, CH + 2% CHX, and 10% EDTA and treated with irrigating solutions and intracanal medicaments. After the treatments, the specimens were immersed in 10% EDTA (20 minutes), and the solution was analyzed using the enzyme-linked immunosorbent assay. The data were submitted to normality, homogeneity of variance, and Mann-Whitney tests (P.05).Significant differences were found between the irrigating solutions (P.05) and intracanal medicaments for TGF-β1 (P.05). No VEGF release was detected for any group. Our results showed no significant differences among the TAP + 2% CHX and EDTA groups for TGF-β1 but a significant difference between CH + 2% CHX and the other groups (P.05).The use of 2% CHX as the irrigating solution, CH as the intracanal medicament, and 10% EDTA as the final irrigation provides higher TGF-β1 release from the cervical root dentin, whereas VEGF was not detected. Moreover, TAP and 2% CHX with 10% EDTA as the final irrigation resulted in greater TGF-β1 release from cervical root dentin than CH + 2% CHX.

Introduction This study evaluated the bacterial levels after regenerative endodontic procedures and their correlation with the treatment outcome using molecular microbiology methods. Methods Root canal samples of 15 necrotic immature teeth were analyzed by quantitative polymerase chain reaction. Bacteria were counted before treatment (S1), after irrigation with 6% sodium hypochlorite (S2), and after intracanal dressing (S3) using either triple antibiotic paste (n = 7) or calcium hydroxide with chlorhexidine (n = 8). The Wilcoxon test for related samples and the Mann-Whitney test were used for statistical analysis (P Results All S1 and S2 samples were positive for bacteria, but the number of positive S3 samples decreased to 53.3% (P = .001). Overall, there was a significant reduction of bacterial levels after each treatment step (S1–S2, P = .001; S2–S3, P = .02). In the triple antibiotic paste and chlorhexidine groups, 57.1% and 50% of S3 samples were positive with median numbers of 6.97 × 103 and 3.59 × 104 bacterial cells, respectively. No significant differences were found between the groups. Periapical healing occurred in all cases despite the presence of low levels of residual bacteria. However, the latter had a negative impact on the thickness of dentinal walls (R2 = 0.0043). Conclusions Although the bacterial levels were drastically reduced after the regenerative endodontic procedures, the residual bacteria influenced the thickness of the dentinal walls.

Objective Warm vertical compaction of gutta-percha is a technique that is used by most specialists for root canal obturation. The sealers currently available exhibit irriversible chemical changes when heated. New biologically active sealers that do not sustain irreversible changes when heated are an attractive alternative to be used with warm vertical compaction obturation technique. The aim of this study was to measure the heat generated by warm vertical compactors inside the root canal, characterize a newly developed root canal sealer at different temperatures and verify its suitability at the actual temperature window used clinically. Methods The typical temperatures generated by two heat carriers in a root canal were assessed by thermocouples. Two premixed root canal sealers TotalFill BC and HiFlow BC (FKG, Switzerland) were allowed to set and they were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction analysis (XRD) immediately after setting and by XRD after 28 days in physiological solution. The ion leaching in solution was assessed by inductively coupled plasma (ICP). The organic component was extracted in acetone and assessed by Fourier transform infrared spectroscopy (FT-IR) for both the unset sealer and sealer subjected to different temperatures. The heat profiles of both sealers were investigated by FT-IR and thermographic analysis. Results None of the devices tested achieved the temperatures set on the dial. The highest temperatures were coronal followed by apical for both devices. The sealers were identical except for the vehicle. The inorganic components included tricalcium silicate, dicalcium silicate and zirconium oxide. No calcium hydroxide was produced by any of the sealers after immersion in physiological solution but calcium was released in solution. The chemistry of both sealers was modified when heated but both recovered when cooled. Significance The heat carriers were unreliable and the heat generated inside the canal was not the same as the temperature set on the dial. Since both sealers had identical chemistry save for minimal modifications to the organic component and were both resistant to heat, TotalFill BC sealer is recommended for use with warm vertical compaction technique as it is cheaper and as effective as the HiFlow.

Introduction The use of medicaments has been recommended for the treatment of root canal infection. This study evaluated the antimicrobial effect of a well-known biocidal agent, sodium dichloroisocyanurate (NaDCC), by comparing it with calcium hydroxide [Ca(OH)2] using an engineered 3-species biofilm root canal model. Methods Thirty-eight human single-rooted teeth were decoronated and chemomechanically prepared before inoculation using Enterococcus faecalis, Actinomyces viscosus, and Streptococcus mutans using a flow cell model for 4 weeks for biofilm formation. The samples were randomly divided into 3 groups: NaDCC (n = 12), Ca(OH)2 (n = 12), and positive control (no medicament, n = 14). The medicaments were placed using a Lentulo spiral. After a contact time of 7 days, the roots were crushed and plated on selective media. Bacterial identities were confirmed with the use of selective media. Colony-forming units were calculated (CFU/ml). Descriptive statistics (mean and standard deviations) were calculated. Results Seven-day dressing with NaDCC or Ca(OH)2 presented with no growth. For the positive control, the mean colony-forming units were 2.97E4 ± 3.42E4 (CFU/ml). All previously inoculated strains were recovered in the control group. Conclusions NaDCC and Ca(OH)2 when used as intracanal medicaments were able to eradicate an engineered 3-species biofilm in single-rooted teeth in an ex vivo model. NaDCC deserves further investigation as an intracanal medicament.

Calcium hydroxide (Ca (OH)2) paste is widely used as a provisional root canal filling material. This report describes a case of inferior alveolar nerve paresthesia caused by overfilling of Ca (OH)2 paste. A 53-year-old woman had previously undergone root canal filling in the left lower second molar with Ca (OH)2 paste. Immediately after the treatment, she felt sharp pain and paralysis in the left lower lip and chin area and visited our hospital four days later. X-ray examination showed a large radiopacity associated with the left mandibular canal and around the bone marrow from the lower left second premolar to the lower left third molar. We planned a tooth extraction and surgical removal of the Ca (OH)2 paste. However, she declined surgery, and we performed conservative treatment with administration of vitamin B12 and root canal therapy. Approximately one year after her first visit, we filled the root canal with gutta-percha and sealer. The tooth was preserved and paresthesia of the left lower lip and chin largely decreased except for a small remaining numb area. Therefore, it is important to pay scrupulous attention to ensure no extrusion of Ca (OH)2 paste beyond the root apex to avoid complications.

Thermochemical energy storage using the gas-solid reaction of calcium oxide with water vapour is a promising approach especially for high-capacity applications such as CSP. Current research is mainly concerned with lowering reactor cost and therefore concentrating on dynamic systems with granules instead of powder as solid storage material. As stresses affecting the structural integrity of the granules increase with increasing bulk size, small samples as used for thermogravimetric analysis (TGA) might underestimate their impact on granule stability. This work complements existing literature on granule stability by experiments at bulk scale: two shaped granule samples and two ceramic encapsulated granule samples as well as a reference powder were cycled in a lab-scale reactor as well as within a TGA apparatus. Even though preservation of the granule structure was observed after cycling within the TGA apparatus, crushing strength measurements already indicated a decrease of mechanical stability of 81–88% for the shaped granules and 6–11% for the encapsulated granules. As a consequence, structural integrity of the granule bulk was only preserved in case of partial hydration. Given high reactivity, the granule structure – shaped and encapsulated – was destroyed after the first hydration causing a bulk volume expansion of up to a factor of 2.5. Reaction behaviour of the reference powder was consistent despite formation of cm-sized agglomerates. This work confirms that reaction conditions within a bulk are more challenging regarding structural integrity of storage material granules due to greater stresses acting on the single granule. These stresses can be significantly reduced by partial hydration.

In organic acid hydrolysis for xylo-oligosaccharides (XOS) production, organic acids with low flash points and explosion limits can lead to explosion and fire risk. Herein, tartaric acid (TA) as an organic acid with high flash point and no explosion limit was used in the hydrolysis of corncob to produce XOS. Then, the TA-hydrolyzed corncob was used for ethanol production. In TA hydrolysis of corncob, a 56.4 % XOS yield was obtained from the hydrolysate with the conditions of 170 °C, 60 mM TA and 10 min. Meanwhile, 92.1 % TA was recovered from the hydrolysate by the addition of calcium hydroxide. After simultaneous saccharification and fermentation of TA-hydrolyzed corncob, an 82.4 % ethanol yield was obtained with a solid loading of 25 % (w/v, 250 g/L) by Saccharomyces cerevisiae H06. This research provided a relatively safe, simple, and efficient technology for producing XOS and ethanol from corncob.

Chemical composition of temporary cements interferes in the bond strength and quality of the bond interface of glass fiber posts to root dentin. The aim of the present study was to evaluate the influence of different temporary cements on the bond strength of fiberglass posts and resin cement. Thirty-two maxillary central incisor roots were standardized at 15 mm length. The root canals were prepared with Reciproc R50 and filled with a R50 single cone and AH Plus. Ten mm of filling material was removed with a heated Schilder condenser, leaving 5 mm of apical filling material. The roots were randomly distributed into 4 groups (n = 8). In the control group, the root canal was prepared with a standard drill according to the post diameter (DC #1, FGM, Joinville, Brazil), irrigated with 5 mL of distilled water and immediately received the fiberglass post cemented with self-adhesive resin cement. For the other groups, cores were made with temporary intraradicular retainers cemented with different temporary cements: methacrylate-based resin (Bifix Temp - Voco), calcium hydroxide-based (Provicol - Voco) and zinc oxide-based - eugenol-free (Relyx Temp NE - 3M). After 7 days, mechanical removal of the temporary retainers, preparation, irrigation of the root canal and cementation of the fiberglass post were performed, following the same protocol that had been performed in the control group. The roots were sectioned to obtain 3 slices per root third. The most cervical section of each third was used for the push-out test and failure pattern analysis, while the most apical section was subjected to analysis of the adhesive interface by scanning electron microscopy (SEM). The BS data were compared between groups using the two-way ANOVA and Tukey post-test. The failure pattern results were expressed in percentage and compared between groups using the chi-square test and the material adaptation data at the bond interface were evaluated using the Kruskal-Wallis and Dwass-Steel-Critchlow-Fligner tests. The results showed higher BS in the cervical third, with a higher value in the control group (10.8 ± 0.94) and Bifix Temp group (9.78 ± 0.71), with no statistically significant difference between these groups (P .05). The middle and apical thirds showed no statistically significant difference (P .05). As regards the type of failure, a higher percentage of mixed adhesive failures was observed for all groups. Analysis of the adhesive interface by SEM showed that the temporary cement Bifix Temp showed greater adaptation at the bond interface. It was concluded that the methacrylate-based resin temporary cement showed the highest bond strength values and best adaptation to root dentin than the zinc oxide-based and calcium hydroxide-based temporary cements.

Objectives The effectiveness of 1-visit root canal treatment (RCT), especially for teeth with large periapical lesions, are still being debated. Although, the use of chlorhexi-dine (CHX) as a final irrigant have been recommended to provide an optimized approach in 1-visit RCT, there is limited knowledge about the outcome of 1-visit RCT using CHX as the final irrigant.Aim The aim of this randomized clinical trial was to evaluate the healing of mandibular molar teeth with large periapical lesions after RCT that was completed in 1 visit using 2% CHX as a final irrigant, comparing the results with a conventional 2-visit RCT as a control group.Methodology This study is a prospective, parallel-designed, and single-blinded randomized clinical trial. One-hundred asymptomatic mandibular molar teeth with large pe-riapical lesions were randomly assigned to 2 groups. All teeth were instrumented with Reciproc files with 2.5% sodium hypochloride (NaOCl) and 5% ethylenedi-aminetetraacetic acid (EDTA) as irrigants. In the intervention group, half of the teeth were treated in 1 visit, receiving an additional final rinse with 2% CHX be-fore obturation; the other half of the teeth, however, were treated in 2 visits with calcium hydroxide (CH) dressings, in the control group. All root canals were obtu-rated with Reciproc gutta-percha cones and AH Plus root canal sealer. All patients were recalled and investigated clinically and radiographically for 48 months. Pe-riapical healing was evaluated statistically using the Mann-Whitney U test, fol-lowed by the Friedman and the Wilcoxon tests (alpha = 0 .05).Results During the 48-month follow-up process, 86 teeth (44 in 1-visit and 42 in 2-visit group) were examined. There were no significant differences between the 2 groups regarding the radiographic healing rates (1-visit group 91% and 2-visit group 88%) ( P > .05).Conclusion In this study, 1-visit RCT using 2% CHX as final irrigant in asymptomatic mandibular molars with large periapical le-sions produced favorable healing results, similar to 2-visit root canal treatment with calcium hydroxide.

Summary To find an efficient control method for gizzard erosion (GE) caused by fowl adenovirus serotype 1 (FAdV-1) infection in poultry farms, we examined the virucidal effects of commercial disinfectants. In laboratory tests, the virucidal effects of the disinfectants calcium hydroxide (CHO), glutaraldehyde (GLT), orthodichlorobenzene, cresol, and didecyldimethylammonium chloride against FAdV-1s were examined. Among them, CHO and GLT were extremely effective in all tested viruses, even at low concentrations, under the condition of 20°C. However, virucidal effect under the condition of 4°C at low concentrations of GLT was attenuated. Then, in a broiler farm where GE in chickens continuously occurred, we applied 2 combinations of disinfectants on the inside and outside of poultry houses every “chicken-free” period after shipping of chickens. The disinfection effect was then evaluated by gizzard rejection rate in the next flock. We detected GE in the flocks after disinfection with a combination of GLT and CHO at an ambient temperature of approximately 11°C. Moreover, we detected GE in the flock after disinfecting with didecyldimethylammonium chloride and CHO, regardless of the environmental temperature. In contrast, we did not detect GE in the flock after disinfecting with GLT and CHO under the condition of ambient temperature of approximately 21°C. These findings underline the importance of performing thorough disinfection with effective disinfectants during the “chicken-free” downtime to prevent the persistence of GE caused by FAdV-1 infection. It is necessary to use liquid disinfectants such as GLT and to pay close attention to ambient temperatures and the working concentration of disinfectants.

Early-age carbonation can make a significant difference in the formation of hydration products in cement-based materials and alter the microstructural and mechanical performances. To understand in detail the impacts and their contribution to cement hydration, dry-mix cement pastes were exposed to instant carbonation with 0.04 %, 1%, 3%, 10 %, 20 % CO2 concentrations for 2 h prior to further water curing. By increasing the CO2 concentration, an increment in strength gain of samples at 2 h (right after early carbonation) as well as being prolonged by water curing at 1, 3, 7 days was noticed. This agrees with TGA and XRD results, demonstrating that the increases in CO2 concentration resulted in a higher carbonation reaction and hydration degree. 29Si NMR results also indicate that the higher the CO2 concentration the lower the calcium to silica ratio (Ca/Si); thus, there is a higher degree of polymerization to promote early hydration. It can be concluded that early carbonation of 2 h in particular with a high CO2 concentration can be beneficial for further cement hydration due to the consumption of calcium hydroxide (CH) and nuclei site effect of calcite crystals, resulting in better microstructural properties and mechanical performance.

Background Nowhere in the consideration of dental care involving endodontics does a patient become more vulnerable to potentially life-changing injuries than during a root canal procedure on the mandibular dentition that may invade and injure the neurovascular anatomy. Case Description The authors present a series of 5 cases wherein using calcium hydroxide as a disinfection strategy in endodontics caused serious neurologic injury to the treated patients. The mechanism in all cases was the inappropriate use of needle applications resulting in significant overfill into the inferior alveolar nerve space. Although calcium hydroxide has been recognized and used as a meaningful disinfectant in endodontic therapy for many years, the dangers and risks associated with a needle delivery technique are discussed and analyzed with recommendations based on current research to minimize risk. Conclusions and Practical Implications A literature search revealed that the 5 cases are not solitary cases; indeed, consequences of calcium hydroxide overfills have been described before. Therefore, a clinician initiating root canal therapy on a mandibular posterior tooth should always be mindful of the vital neurovascular anatomy, which commonly approximates the ends of these roots. Preoperative cone-beam computed tomographic imaging and the thoughtful delivery of medicaments in treatment can help the clinician manage close proximity to neural anatomy and avoid potential injuries.

Thermal energy storage is a key component for power supply based on concentrating solar power. A promising thermochemical storage material in terms of cost-efficiency, storage density and reaction temperatures is based on the chemical reaction of calcium oxide with water. Handling of the solid materials, however, has proven to be difficult due to their powdery state particularly in dynamic storage systems. It is therefore proposed in the presented work to modify calcium hydroxide powder with nanostructured flow agents to improve the powder's flowability. Therefore, five additives consisting of nanostructured silicon and/or aluminium oxide were mixed systematically with calcium hydroxide powder and the flowability of the mixtures was determined using a ring shear cell. Four additives caused an improved flowability of the powder with additive weight fractions of 6–12%. After thermochemical cycling of the mixtures, however, flowability of the mixtures was clearly decreased while that of the pure powder was increased. Analysis of the samples showed a correlation between growth in particle size and increased flowability. Additionally, formation of calcium silicate and/or aluminate phases led to a decrease in absolute heat release of up to 50% as measured by thermal flux calorimetry, although some of the side products seemingly add to the measured heat release by hydrating exothermally. Based on these results, stabilisation of a moderately increased particle size preferably without the addition of additives is recommended, as a sole prevention of agglomeration by means of flow agents does not result in a manageable storage material.

In this study, the removal of tetracycline from aqueous solutions with chitosan obtained from mussel shells was optimized and investigated using responce surface methodology. For this aim, the central composite design was used to optimize the four variable factors (sorbent dosage (0.4–1.0 g), time (20−60 min), temparature (10−30 °C) and initial TC concentration (50−100 mg/L)) for the removal of TC from aqueous solutions by chitosan obtained from mussel shells. According to the RSM analysis results, optimum conditions for maximum TC removal efficiency were determined as 90.5 mg/L for initial TC concentration, 35.9 min for time, 29.9 °C for temperature and 0.4 g for sorbent dosage. It was observed that the tetracycline was crystallized on mussel shells. According to the results of XRD after adsorption, the content of mussel shells were observed as 60% calcite, 5.6% overite, 9.4% aragonite and calcium hydroxide 25%, respectively. As a result, experiments showed that chitosan obtained from mussel shells were a good adsorbant for tetracycline removal from aqueous solutions.

The removal of Cr, sulfates and Chemical Oxygen Demand (COD) from industrial tannery wastewater by chemical precipitation was carried out using Calcium oxide (CaO) and Calcium hydroxide (Ca(OH)2). Different doses of alkalis, ranging from deficiency to excess hydroxyl species over the stoichiometric necessary, were used to remove theoretically the 100% of Cr [0.3–3.2 g alkali·(g Cr3+)−1]. The precipitation was carried out at room temperature, 10 min of vigorous stirring, 200 r⋅min−1 and a settling time of 24 h, followed by separation and characterization of liquid product. As result of addition of alkalis, pH underwent increase as did the alkali concentration. The removal of Cr, and sulfates also increased as alkali concentration did, although for first species the changes at higher alkali contents were less evident. COD removal on the other hand, did not follow a unique trend, instead exhibited a maximum. Based on our results, selection of a specific dose of alkali was carried out taking as reference the efficiency on total chromium removal, keeping the pH in the range 7 to 9 to ensure Cr precipitation as chromium hydroxide. With those conditions, jar test was used to produce enough liquid product in order to determine the removal percent of several other species. The removal percent of the species was as follows: Cr, SO42−, ZnSO4, FeSO4, CN−1, NiSO4, Fe2[Fe(CN)6] at 99.8%, 66.9%, 99.6%, 21.4%, 70.9%, 52.8% and 76.4% with CaO, and 99.8%, 61.6%, 99.9%, 7.1%, 84.0%, 54.4% and 90.5% with Ca(OH)2, respectively.

Synthesis of calcium hydroxide nanoparticles was done by chemical precipitation in aqueous medium at room temperature. Aqueous solution of calcium nitrate tetrahydrate (Ca(NO3)2·4H2O) and sodium hydroxide are used as precursor. The effect of rate of mixing of sodium hydroxide in calcium nitrate tetrahydrate was studied during the synthesis of calcium hydroxide. The prepared Ca(OH)2 powder was characterized by using UV–Vis spectroscopy, TGA and DTA, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM) and energy dispersive X-ray analysis (EDX). From the UV–Vis characterization, an increase in band gap from 4.3 eV to 5.8 eV with increase in mixing rate of sodium hydroxide in calcium nitrate tetrahydrate from 1 ml/min. to 5 ml/min was found respectively. The weight loss in TGA was also found to increase with increase in mixing rate. The change in weight loss and band gap with mixing rate was discussed in terms of growths during synthesis of calcium hydroxide.

The explosion characteristics and influential factors of suspended calcium carbide (CaC2) dust were studied using a 20-L spherical vessel. Acetylene (C2H2) and calcium hydroxide (Ca(OH)2) are the reaction products of CaC2 and water. Therefore, C2H2/Ca(OH)2 mixture was used as the reference sample in the experiment. Experimental results showed that the water content in the environment (air relative humidity and external water drops) had significant impacts on CaC2 dust explosion. The explosibility of CaC2 dust enhanced with the increasing air relative humidity In the experiments, CaC2 dust and dry water were equally proportioned when the value of stoichiometric ratio R was 1. When the concentration of hybrid CaC2/dry water increased, the value of Pex of CaC2/dry water explosion rose first and then stabilized at 0.74 MPa, and the value of (dP/dt)ex showed a trend of rising first and then declining after reaching the maximum value of 238.25 MPa s−1. Pex and (dP/dt)ex of pure C2H2 explosion and C2H2/Ca(OH)2 hybrid explosion increased at the early stage and then decreased for the increasing C2H2 content. Pex and (dP/dt)ex of the three samples increased in the following order: hybrid CaC2/dry water

Portland cement acts as binding material for the aggregates when it hydrates and forms C-S-H gel in conventional concrete and further, cement production growing 5% annually. For 1-ton cement production, a large quantity of energy is required approximately 120–130 electricity units and it emits 0.6–0.75ton CO2 in the atmosphere, which is responsible for the greenhouse effect and 7% pollutants in the atmosphere. This study was done to check the performance of the durability behavior of AAC. However, it is the polymerization process that makes fly ash a binding material in alkali-activated concrete. Calcium hydroxide is produced in the earlier case upon the hydration process of Portland cement, while no C-S-H gel and lime are produced in alkali-activated concrete. Therefore, a futuristic sustainable material that can be alkali-activated concrete requires confirmation of durability when exposed to an aggressive environment. In alkali-activated concrete strength is gained through polymerization and hydration. The study has been undertaken to place data in one place for the convenience of future research and identify the scope of various durability aspects for future research. Various aspects of durability which have been discussed in this paper are sulphate, chloride, acid resistance, and permeability.

International audience; Calcium oxide, calcium hydroxide and calcium carbonate were tested for the CO2/CH4 reaction in a dielectric barrier discharge plasma reactor under humid conditions. It appeared that the presence of water in the gas stream enhanced slightly the selectivity to CO and H2 syngas on each support (2 to 5 %), contrary to the selectivities to CxHy that decreased (0.5 to 2 %). The water showed little effect on oxygenates selectivities (in the order of 0.1%) compared to dry treatment. The three materials were characterized by thermogravimetric analysis and infrared spectroscopy prior and after, dry and humid, plasma treatments. Addition of humidity in the plasma gas stream led to the formation of calcium hydroxide on the surface of CaO and enhanced the carbonation of Ca(OH)2. We showed that the carbonation of Ca(OH)2, H2O proceeded through simultaneous CO2 capture and H2O release, highlighting an oscillating behavior.

Enterococcus faecalis is a microorganism commonly detected in persistent endodontic infections which leads to root canal failure. It can gain entry into the root canal system during treatment, between appointments or even after the treatment has been completed. The use of the effective intra-canal medicaments can significantly enhance bacterial elimination during root canal treatment. The aim of the study was to evaluate and compare the antibacterial efficacy of Teatree oil, Nisin and Calcium hydroxide against E. faecalis. Typtic Soya agar plates were prepared. The agar well diffusion method was used and plates were incubated at 37 °C for 24hr. The antibacterial efficacy was then evaluated. The zone of inhibition (mm) of each antimicrobial medicament was measured by standard method. Maximum antibacterial efficacy was exhibited by Tea tree oil followed by Nisin and Calcium hydroxide. The results showed that Teatree oil and Nisin have better antibacterial efficacy than the routinely used Calcium hydroxide and they can be used as an alternative intra-canal medicament in endodontics.