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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/).

A continuous search for bioactive materials capable of supporting the replacement of damaged pulp tissue, with effective sealing potential and biocompatibility, has represented the attention of studies over the last decades. This study involves a narrative review of the literature developed by searching representative research in PUBMED/MEDLINE and searches in textbooks associated with the mechanism of action of bioactive materials (calcium hydroxide, mineral trioxide aggregate (MTA), and calcium silicate cements). The reflective analysis of the particularities of the chemical elements of these materials, considering the tissue and antibacterial mechanism of action, allows a better understanding of the characteristics and similarities in their tissue responses. Calcium hydroxide paste remains the antibacterial substance of choice as intracanal dressing for the treatment of root canal system infections. Calcium silicate cements, including MTA, show a favorable biological response with the stimulation of mineralized tissue deposition in sealed areas when in contact with connective tissue. This is due to the similarity between the chemical elements, especially ionic dissociation, the potential stimulation of enzymes in tissues, and the contribution towards an alkaline environment due to the pH of these materials. The behavior of bioactive materials, especially MTA and the new calcium silicate cements in the biological sealing activity, has been shown to be effective. Contemporary endodontics has access to bioactive materials with similar properties, which can stimulate a biological seal in lateral and furcation root perforations, root-end fillings and root fillings, pulp capping, pulpotomy, apexification, and regenerative endodontic procedures, in addition to other clinical conditions. Resumo Uma busca contínua de materiais bioativos com capacidade de substituir o tecido pulpar danificado, com efetiva capacidade de selamento e biocompatibilidade, tem representado a atenção e foco de muitos estudos ao longo das últimas décadas. Este estudo envolve uma revisão narrativa da literatura desenvolvida por meio de pesquisas representativas encontradas no PUBMED/MEDLINE e pesquisas em livros didáticos associadas ao mecanismo de ação de materiais bioativos (hidróxido de cálcio, agregado de trióxido mineral (MTA) e cimentos de silicato de cálcio). A presente análise reflexiva das particularidades dos elementos químicos destes materiais bioativos, considerando o mecanismo de ação tecidual e antibacteriano, possibilita um melhor entendimento das características e similaridades no comportamento tecidual. A pasta de hidróxido de cálcio continua sendo a substância antibacteriana de escolha como medicação intracanal para o tratamento das infecções do sistema de canais radiculares. Este fato se deve a disponibilidade química de íons cálcio e hidroxila do hidróxido de cálcio aos tecidos, e a inibição enzimática bacteriana. Os cimentos de silicato de cálcio, dentre os quais inclui o MTA, apresentam uma resposta biológica favorável ao estímulo à deposição de tecido mineralizado nas áreas seladas e em contato com tecido conjuntivo. Este fato é decorrente da similaridade entre os elementos químicos, em especial devido a dissociação iônica, ao potencial estímulo de enzimas teciduais, e a contribuição com um meio alcalino decorrente do pH destes materiais. O comportamento dos materiais bioativos, em especial o MTA e os novos cimentos de silicato de cálcio na atividade de selamento biológico mostraram efetivos. A endodontia contemporânea atualmente conta com o potencial de materiais bioativos com propriedades análogas capaz de estimular o selamento biológico em perfurações radiculares laterais e de furca, em obturações radiculares, capeamento pulpar, pulpotomia, apicificação e procedimentos endodônticos regenerativos, além de outras condições clínicas.

Introduction. Endodontic instruments during root canal treatment come into contact with dentinal debris, irrigation solutions and medication agents, which reminants should be eliminated before sterilization. The aim of the study was to verify the effectiveness of different cleaning methods for removing calcium hydroxide paste residues from the surfaces of the working parts of hand instruments, as well as to propose an effective protocol for cleaning endodontic instruments before sterilization. Material and methods. Forty-two new hand endodontic instruments were used to remove calcium hydroxide paste from the filled canals of extracted teeth. After contamination with medication, they were divided into the four groups and subjected to individual decontamination methods - mechanical, chemical and ultrasonic, as well as a combined protocol. The instruments were then observed under a light microscope. The effectiveness of the methods was evaluated based on the amount of residual matter on the surface of the working parts of the instruments. Results. The combined protocol showed a statistically significant difference in the achieved level of cleanliness compared to mechanical (?2 = 12.00 p < 0.05) and chemical methods (?2 = 12.00 p < 0.05), but there was no statistically significant difference compared to ultrasonic cleaning in disinfectant solution (?2 = 2.4 p > 0.05). By applying combined protocol, instruments with completely clean surfaces were found, as well as the lowest values of contamination at the level of the entire group of instruments (8.33%). Conclusion. The protocol that consisted of mechanical cleaning with a sponge soaked in chlorhexidine gluconate, chemical soaking in sodium hypochlorite, and ultrasonic cleaning in a disinfectant showed the best efficiency in removing calcium hydroxide residues.

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.

Aim To compare the influence of two methods of agitation of endodontics irrigants, by diffusion of calcium hydroxide [Ca(OH)2] through the dentinal tubules, measuring the pH of the medium where they were kept. Methods Twenty mandibular incisors were prepared using a WaveOne Gold Large file, in a reciprocating movement, and then divided into (n = 10): gutta-percha cone (GPC) or Easy Clean system (ECS) agitation of 1% sodium hypochlorite and 17% ethylenediaminetetraacetic acid. The specimens were filled with Ca(OH)2 paste, placed in flasks with 4 mL of deionized water, and stored in an incubator. The pH was read using a digital pH meter immediately after storage (T0), after 7 (T1), 14 (T2), 21 (T3), and 35 (T4) days. Results Statistical difference between groups was observed regardless of the day pH was measured (p < 0.01). From T2 on, ECS presented higher pH values in comparison with GPC, with significant difference (p < 0.01). Conclusion Agitation of endodontic irrigants with ECS enhances the Ca(OH)2 diffusion, providing higher pH values, from the 14th day on, when compared with GPC.

Moving toward net zero emissions require new approaches and technologies, including capturing CO2 from industrial sources, especially in remote locations where currently using fossil fuels could be unavoidable for generating electricity or machinery for mining, production of cement, steel, hydrogen, gas processing, etc. Mineral carbonation could fix CO2 in a highly stable solid form. This study explores intensifying the carbonation process of natural Canadian silicates and minerals, kimberlite and wollastonite, which are available in mining sites where the emission occurs. Kimberlite is well-known for containing diamonds. After extracting the diamonds, the value of tailings can vary widely depending on the mineral content and the processing costs, while kimberlite is not as reactive as wollastonite for CO2 sequestration purposes. This study explored the effects of ball milling and various methods for intensifying the mineral carbonation process for CO2 sequestration. Calcium and magnesium hydroxides were used as reference materials to assess the effectiveness of the ball-mill reactor. Then, various parameters in the intensification of the carbonation process were investigated, and the effects of additives (sodium hydroxide and magnesium chloride), solvents (pure water and ethanol), and process parameters (temperature, reaction time, and CO2 level) on carbonation and reaction rate, CO2 uptake and mineral conversions were investigated. The carbonated samples were subjected to pH testing, calcimetry, XRD analysis and scanning electron microscopy (SEM). For most feedstocks, water as the main solvent led to higher carbonation and precipitating of different carbonates (hydromagnesite, aragonite, calcite, etc.), while for kimberlite, using NaOH led to higher performance. Ball-milling is designed for purposes such as milling, grinding, etc. The centrifugal forces and related phenomena could limit the contraction of CO2 and other materials in the ball mill jar. However, the results of this study suggest that ball-milling can assist in intensifying mineral carbonation reactions.

The aim of this study was to evaluate in vitro the effect of calcium hydroxide [Ca(OH)2], 2% chlorhexidine gel (CHX) on macrophages (RAW 264.7) to produce pro-inflammatory cytokines and nitric oxide after pretreatment with lipoteichoic acid (LTA) of Enterococcus faecalis. Forty-eight human single-rooted teeth were instrumented with R25.08 (RECIPROC) and sterilized by gamma irradiation. LTA was inoculated in the root canal of each specimen for 96 hours. Specimens were instrumented with 40.06 and 50.05 (RECIPROC) and medicated with: I) Pyrogen-free saline solution (SS); II) 2% CHX gel; III) Ca(OH)2 + SS; or IV) Ca(OH)2 + CHX for 14 days. Three samples (S) were performed of the root canal of each specimen at: S1) immediately after instrumentation; S2) after Ethylenediaminetetraacetic acid (EDTA); S3) after intracanal medication removal. Subsequent quantification of cytokines (IL-1β, TNF-α, MIP-1α, IP-10, G-CSF and IL-6) by immunosorbent assay (ELISA) and nitric oxide by the Griess method was carried-out. Data were submitted to a normality test and then analyzed with one-way ANOVA and Tukey test with a significance level of 5% using GraphPad Prism 6. Ca(OH)2 + SS and Ca(OH)2 + CHX presented lower levels of TNF-α, TNF-α, IL-6, G-CSF and nitric oxide. Ca(OH)2 + SS was the most effective in reducing MIP-1α. CHX was effective in reducing IL-6 and G-CSF. Therefore, the combined intracanal medication of calcium hydroxide and chlorhexidine is effective in reducing the cytokines TNF-α, IL-1β, IL-6, G-CSF and nitric oxide. Resumo O objetivo deste estudo foi avaliar in vitro o efeito do hidróxido de cálcio [Ca(OH)2], clorexidina gel a 2% (CHX) em macrófagos (RAW 264.7) na produção de citocinas pró-inflamatórias e óxido nítrico após pré-tratamento com ácido lipoteicóico (LTA) de Enterococcus faecalis. Quarenta e oito dentes humanos uniradiculares foram instrumentados com R25.08 (RECIPROC) e esterilizados por irradiação gama. LTA foi inoculado no canal radicular de cada espécime por 96 horas. Os espécimes foram instrumentados com 40.06 e 50.05 (RECIPROC) e medicados com: I) solução salina apirogênica (SS); II) CHX 2%; III) Ca(OH)2 + SS; ou IV) Ca(OH)2 + CHX durante 14 dias. Três amostras (S) foram realizadas do canal radicular de cada espécime em: S1) imediatamente após a instrumentação; S2) após ácido etilenodiaminotetracético (EDTA); S3) após a retirada da medicação intracanal. Foi realizada a quantificação subsequente de citocinas (IL-1β, TNF-α, MIP-1α, IP-10, G-CSF e IL-6) por imunoensaio (ELISA) e de óxido nítrico pelo método de Griess. Os dados foram submetidos a um teste de normalidade e então analisados com ANOVA one-way e teste de Tukey com nível de significância de 5% usando GraphPad Prism 6. Ca(OH)2 + SS e Ca(OH)2 + CHX apresentaram níveis mais baixos de TNF -α, TNF-α, IL-6, G-CSF e óxido nítrico. Ca(OH)2 + SS foi o mais eficaz na redução de MIP-1α. CHX foi eficaz na redução de IL-6 e G-CSF. Sendo assim a associação de hidróxido de cálcio e clorexidina é eficaz na redução das citocinas TNF-α, IL-1β, IL-6, G-CSF e óxido nítrico.

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.

To investigate the effect of calcium hydroxide intracanal medicament on the push-out bond strength of resin-based and calcium silicate-based endodontic sealers.A comprehensive search of was conducted for all relevant in-vitro studies. All randomized controlled in-vitro studies that evaluated the effect of calcium hydroxide on the push-out bond strength of resin-based or calcium silicate-based endodontic sealers were assessed. The variables of interest were extracted, and the risk of the included studies was evaluated. The standardized mean difference was calculated and the significance level was set at p value0.05.A total of 26 studies were eligible for analysis. There were 45 independent comparison groups and 1009 recruited teeth. The pooled data showed no significant difference in push-out bond strength between calcium hydroxide and control group in the resin-based group (SMD = 0.03; 95% CI = -0.55, 0.60; p = 0.93), and calcium silicate-based group (SMD = 0.02; 95% CI = -0.31, 0.35; p = 0.90). Most of the studies (21 out of 26) were at medium risk of bias and five studies showed a low risk of bias.The available evidence suggests that calcium hydroxide used as intracanal medication does not influence the push-out bond strength of the resin- and calcium silicate-based endodontic sealers.The results of this meta-analysis suggest that calcium hydroxide used as intracanal medication does not influence the push-out bond strength of resin-based and calcium silicate-based endodontic sealers.

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)

Aim: The aim of this non-inferiority randomized clinical trial was to compare the efficacy of an iodoform-based paste (Guedes-Pinto –(GP)) as a filling material in pulpectomies of primary teeth, and a standard material composed by calcium hydroxide and iodoform (CaOH/Iodof paste; Vitapex®). Design: A total of 104 teeth from 61 children (3–8 years old) were randomly allocated to two groups according to filling materials. Children were followed up for 24 months. The primary endpoint was the treatment success rate evaluated through clinical and radiographic examinations at follow-up, and the secondary outcome was the analysis of the canal filling quality. Differences in the proportion of treatment success was calculated based on 95% confidence intervals (95% CI) and with the Miettinen and Nurminen method in the intention-to-treat population, considering a −20% of the non-inferiority limit. Results: From 104 randomized teeth, 102 were followed up after 24 months (attrition rate of 1.9%). The success rate of teeth treated with the GP paste was 86.8% (95% CI: 69.9–94.9) and 78.4% (95% CI: 61.8–89.1) with the CaOH/Iodof paste. Consequently, a non-inferiority of the GP paste was observed when compared to the CaOH/Iodof paste (P

Antecedentes: el tratamiento de pulpotomía conserva la vitalidad pulpar de los dientes y promueve la cicatrización. Objetivo: determinar los avances del tratamiento de pulpotomía parcial en los últimos 10 años. Criterio de selección: artículos de estudios analíticos, experimentales ECA (ensayos clínicos controlados aleatorizados), revisiones sistemáticas que traten sobre pulpotomía parcial o total. Artículos con nivel de evidencia moderado a alto y seguimiento, control clínico y radiográfico en dientes tratados con pulpotomía publicados desde el año 2011 al 2022. Recopilación y análisis de datos: la evaluación de la calidad metodológica, riesgo de sesgo y extracción de datos se realizó de forma independiente. La calidad metodológica se evaluó con la guía PRISMA para revisiones sistemáticas y metaanálisis; CONSORT para ensayos clínicos aleatorizados y STROBE para estudios observacionales. El análisis del riesgo de sesgo en los estudios observacionales se evaluó con la herramienta de la Escala Newcastle-Ottawa y las revisiones sistemáticas con la herramienta (RoB2) Cochrane. Resultados: de los 54 estudios seleccionados, 11 fueron Revisiones sistemáticas, 33 ensayos clínicos aleatorizados y 10 estudios observacionales. Se observo buen pronóstico en dientes con ápice cerrado, el anestésico más utilizado fue con vasoconstrictor, el hipoclorito de sodio es el irrigante y hemostático más utilizado y los cementos Biocerámicos presentaron el mejor porcentaje de éxito. Conclusiones: los hallazgos de la revisión indican altas tasas de éxito para la pulpotomía; sin embargo, existe un riesgo moderado de sesgo en los estudios incluidos, por lo que los resultados generales deben interpretarse con cautela. Record: pulpotomy is a treatment that promotes pulp healing. Objective: To the aim of this review was to assess the progress of partial pulpotomy treatment in the last 10 years. Selection criteria: analytical articles, experimental studies CCT (Controled Clinical Trial), systematic reviews of partial or total pulpotomy. Articles with moderate to high evidence level and follow-up, clinical and radiographic control in teeth treated with pulpotomy published from 2011 to 2022. Data collection and analysis: the evaluation of methodological quality, risk of bias and data extraction was carried out independently. Methodological quality was assessed with the PRISMA guide for systematic reviews and meta-analyzes, CONSORT for randomized clinical trials and STROBE for observational studies. Risk of bias analysis in observational studies was assessed using the Newcastle-Ottawa Scale tool and systematic reviews using the Cochrane (RoB2) tool. Results: from 54 studies selected, 11 were systematic reviews, 33 randomized clinical trials and 10 observational studies. Good prognosis was observed in teeth with closed apex, the most used anesthetic was with vasoconstrictor, sodium hypochlorite is the most used irrigant and hemostatic and the Bioceramic cements presented the best success rate. Conclusions: the findings of the review indicate high success rates for pulpotomy; however, there is a moderate risk of bias in the included studies, so the overall results should be interpreted with caution. Especialista en Endodoncia http://www.ustabuca.edu.co/ustabmanga/presentacion Especialización

Purpose: This in vitro study evaluated the influence of antimicrobial photodynamic therapy (aPDT), using methylene blue (MB) as photosensitizer (PS) and calcium hydroxide (CH) as intracanal medication on adhesive bond strength, sealing, and integrity of the luting interface of glass-fiber posts to different thirds of endodontically treated root canal dentin. Material and methods: 102 incisors were sorted into 6 groups: a negative control irrigated with deionized water; a positive control irrigated with deionized water and filled with CH; CH + MB 50 mg/L without laser radiation; CH + MB 100 mg/L without laser radiation; CH + MB 50 mg/L radiated by red laser; and CH + MB 100 mg/L radiated by red laser. Push-out bond strength (n = 8), adhesive interface sealing (n = 3), and volume and quantification of voids (n = 6) were assessed using a universal testing machine, confocal laser scanning microscope, and computerized microtomography, respectively. Scanning electron micrographs were obtained from representative samples to qualify the fracture patterns. Push-out bond strength and adhesive interface integrity data were subjected to 2-way ANOVA for repeated measures followed by Tukey's test (α = 0.05). Adhesive interface sealing was evaluated by the inter-examiner Kappa test and submitted to Kruskal-Wallis and Dunns tests (α = 0.05). Results: Assessing the apical region, the positive control and MB100WA + Ca(OH)2 groups showed lower adhesive bond strength compared to the MB100A + Ca(OH)2 group (P < 0.05). The cervical third showed higher bond strength than the apical third for the positive control, MB50WA + Ca(OH)2, MB100WA + Ca(OH)2, and MB50A + Ca(OH)2 groups (P < 0.05). A prevalence of mixed failure was observed in all experimental groups. There were no statistically significant differences in adhesive interface sealing for any of the parameters assessed (P > 0.05). MB100WA + Ca(OH)2 and MB100A + Ca(OH)2 groups promoted a higher volume and quantification of voids compared to the negative control group evaluating the cervical third (P < 0.05). In general, there were no differences in the quantification of voids comparing the intraradicular thirds (P > 0.05), differently to the volume of voids in which, in general, the cervical third promoted higher values compared to the middle and apical thirds (P < 0.05). Conclusion: aPDT with methylene blue PS at 50 mg/L associated with calcium hydroxide as intracanal medication demonstrated satisfactory bond strength, sealing, and integrity of the adhesive interface at any intraradicular depth.

Light bleaching, as a treatment option for discoloured papers, is currently being reconsidered in the British Museum Western Art on Paper Conservation Studio. This research project was carried out in order to determine optimal and practical treatment conditions. Light bleaching experiments on artificially aged modern papers and naturally aged 18th century paper immersed in baths of filtered tap water, deionised water, sodium-based buffers, magnesium bicarbonate and calcium hydroxide at alkalinities ranging from pH 8 to pH 12 of have shown that, in general, solutions at a higher pH are more effective at removing discolouration than solutions at neutral pH values. Filtered tap water and deionised water were significantly less effective than any of the other solutions. Magnesium bicarbonate appeared particularly effective at removing discolouration in the dark as well as during light bleaching when compared to calcium hydroxide at neutral or mildly alkaline conditions. Treatments in calcium hydroxide at higher pH values (pH 10 to pH 12) were sometimes more effective than magnesium bicarbonate but this appeared to depend upon paper type and treatment time. Treatments in the sodiumbased buffers were generally the most effective, suggesting that borax may be an alternative to calcium hydroxide which can be laborious to keep at a stable pH for prolonged treatments. However, great care must be taken to fully rinse sodium tetraborate from the papers after treatment as colour reversion tests have shown that residual sodium tetraborate can lead to excessive discolouration., The British Museum; CSR Project no. 7391; 6 May 2011

Background and Objective: Despite a plethora of studies conducted to date, researchers continue to investigate the best sealer and obturation technique combinations. The aim of this study is to compare the apical seal provided by two bioceramic sealers (Endoseal and Endosequence) with that provided by a calcium hydroxide sealer (Sealapex), and to evaluate the effect of different obturation techniques (cold lateral condensation, continuous wave compaction and single cone) on the apical seal under a stereomicroscope. Materials and Methods: A total of 110 single-rooted mandibular premolar teeth were decoronated, cleaned and shaped using the Endosequence filing system to tip size 30/0.04 taper. Canals were irrigated with 5.25% NaOCl and 17% EDTA. The samples were randomly divided into 11 groups (9 experimental and 2 control groups) according to the designated sealer and technique. Samples were stored in an incubator for 7 days at 37 °C under 100% humidity. Samples were coated with nail varnish except for apical 2 mm and vertically placed in 0.2% rhodamine B dye solution for 48 h. Samples were split longitudinally and viewed under a stereomicroscope at 40× magnification. Results: Insignificant results were obtained between obturation techniques (p = 0.499) whereas statistically significant results were attained based on the type of endodontic sealer (p < 0.001). The overall lowest mean apical microleakage and best sealing ability was demonstrated by Sealapex (2.59 ± 1.20 mm) and amongst techniques by continuous wave compaction (3.90 ± 2.51 mm). Conclusions: Endosequence produced the best apical seal with the continuous wave compaction technique, whereas Endoseal did so with the bioceramic-coated single-cone technique. For the Sealapex sealer, the most effective apical seal was observed using cold lateral condensation. The quality and effectiveness of apical seal differed with the type of endodontic sealer and obturation technique used, and vice versa.

Application of intracanal medicaments may affect the physical properties of root dentine. Calcium hydroxide (CH), a gold standard intracanal medicament, has proven to decrease root dentine microhardness. A natural extract, propolis, has been shown to be superior to CH in eradicating endodontic microbes, but its effect on the microhardness of root dentine is still not known. This investigation aims to evaluate the effect of propolis on root dentine microhardness compared to calcium hydroxide. Ninety root discs were randomly divided into three groups and treated with CH, propolis, and a control. A Vickers hardness indentation machine with a load of 200 g and dwell time of 15 s at 24 h, 3, and 7 days was used for microhardness testing. ANOVA and Tukey’s post hoc test were used for statistical analysis. A progressive decrease in microhardness values was observed in CH (p < 0.01), whereas a progressive increase was observed in the propolis group (p < 0.01). At 7 days, propolis demonstrated the highest microhardness value (64.43 ± 1.69), whereas CH demonstrated the lowest value (48.46 ± 1.60). The root dentine microhardness increased over time when propolis was applied, while it decreased over time after application of CH on root dentine sections.

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.

The purpose of this study was to compare the antibacterial effects of Allium sativum (garlic extract), calcium hydroxide (Ca [OH]This prospective double-blind, controlled, parallel, superiority, randomized clinical trial was carried out on 66 permanent, necrotic incisors associated with asymptomatic apical periodontitis in 66 male patients. Patients were randomly divided into three groups (n = 22) according to the intracanal medications used. After access preparation, four microbiological samples (S) were taken using sterile absorbent paper points as follows: S1: before canal instrumentation and S2: after cleaning and shaping. The third sample (S3) and fourth sample (S4) were taken after the placement of the tested intracanal medications into their corresponding canals for 7 and 14 days, respectively. Total DNA was extracted from microbiological samples and relative quantitative real-time PCRs were done to quantify the relative gene expression fold change (FC) for Enterococcus faecalis and Streptococcus species. At significance level p ≤ .05, the data were statistically analysed in SPSS software using Kruskal-Wallis and Freidman's tests, followed by Dunn-Bonferroni post hoc test for pairwise comparisons.Both bacterial mean FC decreased significantly after mechanical instrumentation (S1 to S2) in all groups. However, no statistically significant differences were found after intracanal medicament placement (from S2 to S3 and from S3 to S4) except in the garlic group. Garlic significantly reduced Enterococcus faecalis FC in S3 and S4 when compared to Ca (OH)Within the study limitations, garlic intracanal medicament has a comparable anti-Streptococcus efficiency to Ca (OH)

The aim of this study was to evaluate clinical and radiographical success of ozonoid olive oil as an indirect pulp capping (IPC) agent in primary mandibular second molar when compared to calcium hydroxide and to evaluate the antimicrobial efficacy of ozonoid olive oil onA split-mouth randomized controlled trial was conducted on 30 primary mandibular second molars in 15 children of age 5-9 years with deep dentinal carious lesion. Teeth were randomly allocated to two groups of 15 each. After achieving local anesthesia and rubber dam isolation, an IPC procedure was performed using ozonoid olive oil in group I and calcium hydroxide in group II. Teeth were evaluated clinically and radiographically at 6 and 12 months of follow-up for success or failure of IPC. The bacterial counts ofThere were no statistically significant differences found between the materials used for IPC (The results of this study showed that the success of IPC is independent of capping material. Ozonoid olive oil, an antimicrobial agent, can also be used for IPC. The success of the IPC procedure depends on a reduction in the bacterial count and sealing of the tooth with hermetic restoration. More clinical studies with a larger sample size and longer follow-up duration are required for understanding the efficacy of this material.Ozonoid olive oil can be used as an IPC agent in primary molars and also for a bacterial reduction in dentinal caries.

Objective Despite several interventions to increase participation in England, most colorectal cancers (CRCs) are diagnosed outside of the screening programme. The aims of this study were to better understand why most CRCs are diagnosed externally, the extent to which this is due to suboptimal uptake of screening, and the extent to which it is due to other factors, such as false-negative test results. Setting / Methods We performed a clinical audit of 1011 patients diagnosed with CRC at St Mark's Hospital (Harrow, UK) between January 2017 and December 2020. Data on the diagnostic pathway and screening history of individuals were extracted from the bowel cancer screening system and assessed using descriptive statistics. Results 446/1011 (44.1%) patients diagnosed with CRC were eligible for screening at the time of diagnosis. Of these, only 115/446 (25.8%) were diagnosed through screening. Among those diagnosed via non-screening pathways, 210/331 (63.4%) had never taken part in screening, 31/331 (9.4%) had taken part but were not up to date, and 89/331 (26.9%) had taken part and were up-to-date (of these, 82/89 [92.2%] had received a normal or weak positive test result, and 5/89 [5.6%] had received a positive result and declined colonoscopy). Conclusion Nearly two-thirds of screening eligible patients diagnosed through a non-screening pathway had never taken part in screening. This represents the single largest source of inefficiency within the screening programme, followed by missed findings and inconsistent participation. Given the improved outcomes associated with screen-detected cancers, there is a strong public health mandate to encourage participation.

To assess the radiographic outcomes and prognostic factors in nonvital immature permanent teeth after apexification with modified calcium hydroxide paste.Clinical and radiographic data were collected from 115 necrotic immature permanent teeth (71 caused by trauma and 44 caused by dens evaginatus) treated with apexification using a modified calcium hydroxide. Postoperative root morphology and changes in radiographic root area (RRA) on periapical radiographs were determined and statistically evaluated. Regression analysis was performed to identify factors associated with the outcomes of apexification.The average time for a calcified barrier formation was 10.66 ± 6.37 months. The root morphology after apexification with calcium hydroxide + iodoform paste was similar to that previously described after calcium hydroxide apexification. Compared with the trauma cases, the dens evaginatus cases revealed more type I (40.91% vs 16.9%) and less type II morphology (45.45% vs 67.61%). Although the changes in RRA were limited, the dens evaginatus cases showed greater increment of RRA than the trauma cases (4.12% ± 5.58% vs 0.70% ± 5.21%, P 0.001). A significant association was found between the preoperative stage of root development and postoperative percentage change in RRA (P 0.001).Teeth caused by dens evaginatus had better outcomes after apexification than teeth caused by trauma. Early stages of root development were associated with superior radiographic outcomes.Apexification provided reliable outcomes in the treatment of immature teeth with pulp necrosis and apical periodontitis, even though the root development is limited. Treatment decision should be made with comprehensive evaluation of prognostic factors.

In order to ensure predictable decontamination of the root canal system, chemo-mechanical preparation of the root canal space is sometimes supplemented with the use of intracanal medication. As microbial control of the root canal space is fundamental to the resolution of apical periodontitis, root canal disinfection strategies haven been researched intensively. The use of intracanal medication as a supplementary step to the chemo-mechanical preparation of the root canal space is one of them. Because of the costs and limitations of clinical research it is relevant and common practice to first evaluate alternative or new root canal disinfection modalities in laboratory studies. This involves the simulation of a root canal infection in a laboratory model, on which different disinfection strategies can be tested. When modelling the infected root canal, different levels of infection can be discriminated: suspended bacteria, microbial biofilms and infected dentine. This review describes the experimental models associated with these infection levels and critically appraises their value and methodological details. Suggestions for relevant research methods and experimental models are given, as well as some good practices for laboratory-based microbiological studies.

Calcification is a common finding in endodontic cases after regenerative endodontic therapy (RET). We aimed to identify the prevalence of intracanal calcification after RET and to compare intracanal calcification outcomes in RET using either calcium hydroxide [Ca(OH)We searched PubMed, Web of Science, ProQuest DissertationsTheses, and Scopus databases for clinical, cross-sectional, case-control, and cohort RET studies published until May 2020 in the English language and reporting a calcified case after RET. The Cochrane risk-of-bias tool for randomized trials and Risk of Bias In Non-randomized Studies of Interventions were used for bias assessment. Meta-analyses were performed, overall and separately, for intracanal medicaments using a random-effects model with weighted inverse variance methods. Subgroup analysis was performed according to the calcification type.Eight studies were included. The overall prevalence of intracanal calcification after RET was 30.7% (95% confidence interval [CI]: 0.15-0.45,[Formula: see text]=92.6%), 46.5% with Ca(OH)Based on the studies included, available evidence shows a statistically significant association between complete calcification and Ca(OH)This study highlights the significant association between complete calcification and Ca(OH)

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.

This study has aimed to evaluate the clinical and radiographic success rates of calcium hydroxide pulpotomy (CH) with biostimulation (PBMT) and compare them to that of CH, formocresol (FC), mineral trioxide aggregate (MTA) pulpotomies without PBMT in primary molars. A total of 172 pulpotomies were performed on primary first or second mandibular molars in 94 children who were 5-8 years old. The pulpotomy procedure was performed with four different techniques. In the PBMT group, before the CH placement, 820-nm diode laser radiation was applied to each pulp-stump for 12 s (10 mW, 2.5 J/cm

In this paper, the yeast wastewater secondary treatment effluent using catalytic odor oxidation treatment, using an orthogonal reaction experiment to determine the best reaction conditions, and the online monitoring of the pH, oxidation-reduction potential (ORP), and liquid ozone concentration monitoring, to the catalytic odor oxidation reaction, chemical oxygen demand (COD), and color removal effect were analyzed. The results showed that the optimal reaction condition for the advanced treatment of yeast wastewater by catalytic ozonation was accomplished with manganese dioxide used as the catalyst and a catalyst dose of 6 g·L−1, pH of 12, and catalytic ozonation reaction time of 20 min. The COD was effectively reduced from 880 mg·L−1 to 387 mg·L−1 under this condition, the chroma was reduced from 700 times to 40 times, and these two parameters of the effluent could meet the standard of GB25462-2010. The real-time monitoring system showed that the whole reaction can be divided into two processes. The first 14 min was the indirect reaction of ozone and then the direct oxidation reaction of ozone. This process was further verified by the change trend of COD and the amount of ozone depletion by COD removal. The average ozone consumption levels of the two stages were 1.97 and 4.91 mgO3·mgCOD−1. This system can effectively monitor the reaction of the catalytic odor oxidation in the complex system to guide the effective use of ozone in practical engineering applications.

This study aimed to evaluate the effect of silver nanoparticles (AgNPs) alone or in combination with calcium hydroxide (Ca(OH)2) on the proliferation, viability, attachment, migration, and osteogenic differentiation of human mesenchymal stem cells (hMSCs). Different concentrations of AgNPs alone or mixed with Ca(OH)2 were prepared. Cell proliferation was measured using AlamarBlue, and hMSCs attachment to dentin disks was evaluated using scanning electron microscopy. Live–dead imaging was performed to assess apoptosis. Wound healing ability was determined using the scratch-migration assay. To evaluate osteogenic differentiation, the expression of Runt-related transcription factor (RUNX2), Transforming growth factor beta-1 (TGF-β1), Alkaline Phosphatase (ALP), and Osteocalcin (OCN) were measured using real-time reverse transcriptase polymerase chain reaction. ALP staining and activity were also performed as indicators of osteogenic differentiation. AgNPs alone seemed to favor cell attachment. Lower concentrations of AgNPs enhanced cell proliferation. AgNP groups showed markedly less apoptosis. None of the medicaments had adverse effects on wound closure. The expression of TGF-β1 was significantly upregulated in all groups, and OCN was highly expressed in the AgNP groups. AgNPs 0.06% showed the most enhanced ALP gene expression levels, activity, and marked cytochemical staining. In conclusion, AgNPs positively affect hMSCs, making them a potential biomaterial for various clinical applications.

Background This study aimed to compare the efficacy of EndoActivator, passive ultrasonic irrigation, and Ultra X in removing calcium hydroxide from the artificial grooves in root canal walls. Methods The root canals of 50 extracted human maxillary incisors were instrumented by using the ProTaper rotary system up to #F4 (size 40/0.06 ProTaper) and the teeth were split longitudinally. Lateral grooves were created in the apical and coronal parts of one half and the middle part of the other half. Calcium hydroxide paste was applied to the grooves and the root halves were reassembled. After seven days, the calcium hydroxide was removed from the canal by using one of the EndoActivator, passive ultrasonic irrigation, and Ultra X devices; one group went without irrigation (control group). The CH remnants in the grooves were scored at 20× magnification. The data were analyzed by using the Kruskal–Wallis, Dunn’s post hoc, and Friedman tests. P < 0.05 was considered to be statistically significant. Results No statistically significant difference existed among the experimental groups at the coronal and middle grooves (P > 0.05). However, Ultra X was significantly more effective than passive ultrasonic irrigation at the apical grooves (P = 0.023). Conclusion Within the limitations of this study, Ultra X can be reported to remove the calcium hydroxide from the apical third more efficiently than passive ultrasonic irrigation.

The objective of the present study was to investigate the pH, volumetric alteration, antimicrobial action, and effect on biofilm matrix polysaccharides of calcium hydroxide (CH) pastes with different vehicles available in endodontics: CH + propylene glycol (CHP), UltraCal XS®, Metapaste®, and Metapex®. The pH was analyzed at different time intervals using a pH meter. For volumetric alteration, a microtomographic assay was performed before and after immersion in water. Enterococcus faecalis was chosen for microbiological tests. The bacterial viability and extracellular matrix were quantified with direct contact evaluation (dentin blocks) and at the intratubular level (dentin cylinders) using LIVE/DEAD BacLight and Calcofluor White dyes via confocal laser scanning microscopy (CLSM). Kruskal–Wallis and Dunn’s tests were used to analyze pH and direct contact assays, while one-way ANOVA and Tukey tests were used to analyze volumetric alteration and intratubular decontamination (α = 0.05). Higher pH values were obtained during the initial days. Volumetric alterations were similar in all groups. Lower bacterial viability was obtained for dentin blocks and cylinders when CH pastes were used. UltraCal XS and Metapex had lower values for the extracellular matrix. The pH of all CH pastes decreased with time and did not promote medium alkalization for up to 30 days. CH paste can reduce bacterial viability through direct contact and at an intratubular level; however, UltraCal XS and Metapex are involved with lower volumes of extracellular matrices.

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.

This study aimed to evaluate the pulpal responses of monkey's pulp after direct pulp capping (DPC) with the novel mineral trioxide aggregate containing phosphorylated pullulan-based material (MTAPPL). Seventy-two teeth were randomly divided into four groups: MTAPPL; Nex-Cem MTA (NX); TheraCal LC (TH); and Dycal (DY). Histopathological changes in the pulps were observed at days 3, 7 and 70. On day 3, mild inflammatory responses were observed in the MTAPPL, no to moderate inflammatory responses in the TH, whereas moderate inflammatory responses in the NX and DY. No mineralized tissue formation (MTF) was observed in all groups. On day 7, no or mild inflammatory responses were observed in all groups. Initial MTF was observed except for DY. No inflammation with complete MTF including presence of odontoblast-like cells was observed in the MTAPPL, NX and TH groups at day 70. These findings indicate that MTAPPL could be an efficient DPC material.

Made available in DSpace on 2022-05-01T12:40:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Objectives: The aim of this study was to characterize polycaprolactone-based nanofiber scaffolds (PCL) incorporated with calcium hydroxide (CH) and evaluate their bioactivity on human dental pulp cells (HDPCs) when loaded with fibronectin (FN). Materials and methods: CH (0.1%; 0.2%; 0.4% w/v; or 0%) was incorporated into PCL (10% w/v) scaffolds prepared by electrospinning. Morphology and composition were characterized using SEM/EDS. HDPCs were seeded on the scaffolds and evaluated for viability (alamarBlue; Live/Dead), and adhesion/spreading (F-actin). Next, scaffolds containing 0.4% CH were loaded with FN (20 µg/mL). HDPCs were evaluated for viability, adhesion/spreading, migration (Trans-well), gene expression (RT-qPCR), alkaline phosphatase activity (ALP), and mineralization nodules (Alizarin Red). Data were submitted to ANOVA and post-hoc tests (α = 5%). Results: Nanofibers with larger diameter were seen as CH concentration increased, while there was no effect on interfibrillar spaces. An increase in cell viability was seen for 0.4% CH, in all periods. Incorporation of CH and FN into the scaffolds increased cellular migration, spread, and viability, all intensified when CH and FN were combined. ALPL and DSPP expression, and ALP activity were not affected by CH and FN. COL1A1 was downregulated in all groups, while DMP1 was upregulated in the presence of CH, with no differences for the groups loaded with FN. CH increased the formation of mineralized matrix, which was not influenced by FN. Conclusions: In conclusion, the incorporation of CH enhanced the odontogenic potential of HDPCs, irrespective of the presence of FN. The PCL + 0.4% CH formulation may be a useful strategy for use in dentin tissue engineering. Clinical relevance: A change in the form of presentation of calcium hydroxide-based materials used for direct pulp capping can increase biocompatibility and prolong the vitality of dental pulp. Department of Morphology and Pediatric Dentistry School of Dentistry São Paulo State University (UNESP) Department of Dental Materials and Prosthodontics School of Dentistry São Paulo State University (UNESP) Department of Physiology and Pathology School of Dentistry São Paulo State University (UNESP) Department of Morphology and Pediatric Dentistry School of Dentistry São Paulo State University (UNESP) Department of Dental Materials and Prosthodontics School of Dentistry São Paulo State University (UNESP) Department of Physiology and Pathology School of Dentistry São Paulo State University (UNESP)

A simple visual colorimetric method based on arsenomolybdic acid-crystal violet ion-associate pair formation is described for the detection of As in groundwater at about 10, 25 and 50 μg L−1 levels.

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.

Identification and rapid characterization of novel supplementary cementitious materials (SCMs) is a critical need, driven by shortfalls in conventional SCMs. In this study, we present a discussion of recently developed reactivity tests – the R3 test, the modified R3 test, the lime strength test, and the bulk resistivity index test. These tests measure reactivity parameters such as heat release, bound water, calcium hydroxide consumption, strength, and bulk resistivity. All tests can screen inert from reactive materials. To additionally differentiate pozzolanic and latent hydraulic materials, two parameters, for example, calcium hydroxide consumption and heat release, are needed. The influences of SCM bulk chemistry, amorphous content, and fineness on measured reactivity are outlined. Reactivity test outputs can predict strength and durability of cement paste/mortar/concrete; however, caution must be exercised as these properties are influenced by a variety of other factors independent of reactivity. Thoughts are provided on using reactivity tests to screen materials for concrete durability.

Aim To evaluate the antibacterial efficacy of calcium hydroxide (CH) with antibiotic combinations: daptomycin and gentamicin against Enterococcus faecalis (E. faecalis) dentinal biofilm. Materials and methods Sixty freshly extracted single-rooted mandibular premolars were inoculated with E. faecalis(ATCC 29212) (n = 30) (group A) and clinical isolates (n = 30) (group B) for 3 weeks to form a biofilm. The tooth samples of groups A and B were randomly divided into three subgroups of 10 each, groups 1A and 1B (CH), groups 2A and 2B (CH+G), groups 3A and 3B (CH+D), depending on the medicaments to be placed for one week. The difference between initial and final CFU was calculated and statistically analyzed. Results Among the clinical isolates, CH-antibiotic combinations were more effective than CH alone, which was statistically significant (p = 0.006). Conclusion The dentinal biofilm of clinical isolates of E. faecalis strains exhibited more reduction in bacterial colonies with CH in combination with antibiotics (D and G). Clinical significance Daptomycin and gentamicin when used as an intra-canal medicament in combination with CH are effective in eliminating E. faecalis. Keywords: Calcium hydroxide, Daptomycin, Dentinal biofilm, E. faecalis, Gentamicin.

Naturally occurring in citrus fruits, citric acid is categorized as a weak organic acid, which may exist both as a monohydrate or in an anhydrous form. In biochemistry, this organic acid acts as an intermediate in an essential metabolic process in all aerobic organisms called the Krebs cycle. The literature on citric acid in the context of endodontics up to June 2020 was reviewed using PubMed and MEDLINE. This review aimed to address the antibacterial efficacy of citric acid on endodontic microbiota, its effectiveness on the smear layer, the effects of its toxicity on fracture resistance of dentin, as well as the effectiveness of this acid on the removal of intra-canal medicaments. This report also addressed citric acid-containing endodontic irrigants.

Recently, the capture of carbon dioxide (CO2) using alkaline waste and byproducts has garnered considerable interest. Construction sludge may be categorized as alkaline waste, as it often exhibits high alkalinity during its generation or intermediate treatment. Hence, researchers have attempted to accelerate pH neutralization and recycle alkaline construction sludge by curing it under a high CO2 concentration. By exposing concentrated CO2 gas to an alkaline sludge, cement hydrates such as calcium hydroxide and calcium–silicate–hydrate gels form calcium carbonate (CaCO3). Subsequently, the generation of CaCO3 is expected to reduce the pH of the sludge. However, the amount of CO2 captured in sludge has not been investigated extensively, unlike those of other alkaline wastes. Therefore, the amount of CO2 captured in alkaline sludge that is associated with pH neutralization is evaluated in this study. It is demonstrated that accelerated carbonation tests using a CO2 incubator and carbonate content evaluation tests based on the gas pressure method successfully reveal the amount of CO2 captured in the alkaline sludge that is associated with pH neutralization. Additionally, the test results show that the amount of mCO2 (i.e., the amount of CO2 captured per 1 g of dry mass of alkaline sludge) increases with ΔpH (ΔpH is the difference between the initial pH and the pH after the alkaline sludge is neutralized). A maximum of 0.021 g of CO2 is captured per 1 g of dry mass of alkaline sludge when the addition ratio of quicklime AQL = 3% and 0.040 g when AQL = 6%. The CO2 capture ratio mCO2/mCO2max, which represents the ratio of CO2 captured in the sludge to the maximum capturing capacity, increases with ΔpH. CO2 capture ratios of up to 90.0% and 84.9% are recorded when AQL = 3% and AQL = 6%, respectively. It is discovered that a higher AQL results in a higher mCO2. Moreover, the test results indicate that a higher AQL causes a more significant change in the CO2 capture ratio, even when the pH decreases slightly.

The study is an investigation into the effects of CDA and Ca (OH)2on geotechnical properties of expansive (Sample A) and loose soil (Sample B). The experiments were designed to study the effects of adding CDA in various percentages by weight (5%, 15% and 15%) of dry soil with 5% constant Ca (OH)2, which produces pozzolanic reactions in soil samples. Sample A was collected at Moniya, Ibadan, Sample B from The polytechnic, Ibadan and, cow dung was obtained from a farm settlement at Ilora, Oyo State, the dung was air dried and then calcined at 5000C – 6000C, after which it was sieved using 600µm sieve. The samples were subjected to the following laboratory tests; Natural moisture content, Particle (grain) size analysis, Atterberg limit test, Compaction test, California bearing ratio (CBR) test. The NMC test shows that sample A retains more water than sample B given by the values 26% and 6% respectively, the particle size analysis results showed that sample A has highest percentage of clay passing sieve no. 200 (75µm) i.e. 62.86%, while sample B has 7.27%, this indicates that sample A with high silt clay content are susceptible to volume changes when wet. The liquid limit and plasticity index for sample A is 49% and 28% respectively while sample B is a cohesionless soil. This shows that sample A has high clay content and its load bearing capacity could be reduced when wet. The AASHTO system classified sample A as A-7-6, and sample B as A-3. This shows sample A is fair to poor while sample B is excellent to good. The maximum dry densities ranged from 1.61mg/m3 to 1.87mg/m3and Optimum moisture contents range from 19.2% to 16.36% respectively. The CBR value of sample A as to the varying percentage are 2.07%, 10.62% (0% CDA & 5% Ca(OH)2) , 12.69%, 16.77%, 31.41% while CBR value of sample B are thus: 32.7%, 27.06% (0% CDA & 5% Ca(OH)2), 12.09%, 16.2%, 16.74%. It was then observed that CDA at 15% and Ca(OH)2 at 5% is the optimum for expansive soils while adding CDA and Ca(OH)2 to loose soil will increase the OMC and thus reduce its engineering properties.

The study aimed to investigate the bond strength of epoxy resin-based sealer following five different calcium hydroxide paste removal methods in oval-shaped root canals.Sixty single-rooted human mandibular premolars having an oval-shaped root canal as evidenced by radiographs were decoronated and instrumented to size 40/0.04, medicated with calcium hydroxide paste for 7 days, before being randomly assigned to the conventional needle irrigation (CNI), manual dynamic agitation (MDA), sonic irrigation (SI), passive ultrasonic irrigation (PUI), and XP-endo Finisher (XP) groups to be irrigated using different irrigation systems. All specimens were then obturated using an epoxy resin-based root canal sealer and warm vertical compaction obturation technique. After 7 days, each specimen was sectioned into 1 mm root slices at the coronal, middle, and apical third of the root canal and tested for the push-out bond strength using a universal testing machine.The XP group was the only group that had comparable bond strength to the control group at every level of the root canal following removal of calcium hydroxide medicament (Calcium hydroxide interfered with the bonding of epoxy resin-based sealer to root canal walls. Irrigation with the XP increased the bonding sealer at every level of the root canal.The XP was efficacious as a final rinse agitation technique to promote the bonding of the epoxy resin-based sealer at every level of the root canal following calcium hydroxide medication.

The widespread use of renewable energy requires the support of high-capacity energy storage systems. This work proposes a thermochemical energy storage system for concentrated solar power plants based on the reversible hydration/dehydration process of the calcium hydroxide. It is a single fluidised bed reactor concept with alternating dehydration-hydration processes, charging and discharging alternating reactions, with superheated steam as fluidising agent. The system has been modelled using Aspen Plus™, including equilibrium data and hydrodynamic performance of the reactor. The model has been used to evaluate the effect of different parameters of the reactor, such as geometry, average particle size, or inlet streams conditions, on the performance of the reactor and the system. The thermal integration of the system was optimised using pinch analysis. For the proposed layouts, round-trip efficiencies values of 68 % are obtained. The economic analyses show specific investment costs between 4170 $/kWe and 3250 $/kWe for plants in the range of 31 MW to 45 MW, which are competitive with those expected for plants with storage of molten salts in this power range. LCOE values between 67 $/MWh and 83 $/MWh were obtained. The analyses show how these values highly depend on the fresh material replacement requirements related to the deactivation of the material and operational strategies. The results show the interest in further developments of this concept for concentrated solar power plants.

O objetivo deste estudo foi avaliar a remoção da pasta de hidróxido de cálcio de canais simulados curvos utilizando a Easy Clean®. Foram utilizados 50 blocos de acrílico com canais laterais curvos simulados nos terços cervical, médio e apical. Os blocos foram preparados com o sistema ProDesign Logic®. Inicialmente foram explorados com uma lima k-file 10mm até a saída do forame. Em seguida foi definida a Glide Path e a patência – Lima Glide 25.01 e a modelagem final foi realizada com a lima 25.05 até o comprimento de trabalho. O procedimento de irrigação foi realizado com soro fisiológico em todo o preparo do canal artificial com uma seringa descartável e agulha NaviTip® (NaviTip®, Ultradent®, Brasil). Ao concluir o preparo dos canais, os espécimes foram secos com cones de papel absorvente. A pasta de hidróxido de cálcio foi inserida nos canais em toda a sua extensão. Para a remoção da pasta de hidróxido de cálcio foi realizada a agitação da solução irrigadora por 20 segundos com o auxílio do instrumento Easy Clean® acoplado a um contra-ângulo acionado na baixa rotação. Esse protocolo foi repetido por 3 vezes, totalizando 9 ml de solução irrigadora e 1 minuto de agitação. Em 40 blocos de resina (95% da amostra) houve limpeza total após a irrigação e utilização do Easy Clean®. Em 10 blocos (5% da amostra) permaneceu UltraCal XS®, principalmente no terço apical dos blocos. Concluiu-se que a irrigação com agitação da Easy Clean® remove efetivamente resíduos da medicação intracanal dos terços cervical e médio dos canais, exceto do terço apical, que ainda apresentou uma quantidade considerável de resíduos. The aim of this study was to evaluate the removal of calcium hydroxide paste from simulated curved canals using Easy Clean®. Fifty acrylic blocks with simulated curved lateral channels were used in the cervical, middle and apical thirds. The blocks were prepared using the ProDesign Logic® system. Initially, they were explored with a 10mm k-file file until the foramen exit. Then the Glide Path and the patency were defined – Glide File 25.01 and the final modeling was carried out with the file 25.05 up to the working length. The irrigation procedure was performed with saline throughout the preparation of the artificial canal with a disposable syringe and NaviTip® needle (NaviTip®, Ultradent®, Brazil). After completing the canal preparation, the specimens were dried with absorbent paper cones. Calcium hydroxide paste was inserted into the channels along their entire length. To remove the calcium hydroxide paste, the irrigating solution was stirred for 20 seconds with the aid of the Easy Clean® instrument coupled to a contra-angle set at low speed. This protocol was repeated 3 times, totaling 9 ml of irrigating solution and 1 minute of agitation. In 40 resin blocks (95% of the sample) there was total cleaning after irrigation and use of Easy Clean®. In 10 blocks (5% of the sample) UltraCal XS® remained, mainly in the apical third of the blocks, which still presented a considerable amount of residues. El objetivo de este estudio fue evaluar la eliminación de pasta de hidróxido de calcio de canales curvos simulados usando Easy Clean®. Se utilizaron 50 bloques de acrílico con canales laterales curvos simulados en los tercios cervical, medio y apical. Los bloques se prepararon utilizando el sistema ProDesign Logic®. Inicialmente se exploraron con lima k de 10 mm hasta la salida del foramen. Luego se definió el Glide Path y la permeabilidad – Glide File 25.01 y se realizó el modelado final con la lima 25.05 hasta la longitud de trabajo. El procedimiento de irrigación se realizó con solución salina durante toda la preparación del canal artificial con jeringa desechable y aguja NaviTip® (NaviTip®, Ultradent®, Brasil). Después de completar la preparación del canal, los especímenes se secaron con conos de papel absorbente. Se insertó pasta de hidróxido de calcio en los canales en toda su longitud. Para eliminar la pasta de hidróxido de calcio, la solución de irrigación se agitó durante 20 segundos con la ayuda del instrumento Easy Clean® acoplado a un contra-ángulo ajustado a baja velocidad. Este protocolo se repitió 3 veces, totalizando 9 ml de solución de irrigación y 1 minuto de agitación. En 40 bloques de resina (95% de la muestra) hubo limpieza total después del riego y uso de Easy Clean®. En 10 bloques (5% de la muestra) permaneció UltraCal XS®, principalmente en el tercio apical de los bloques, que aún presentaba una cantidad considerable de residuos.