Calcium Hydroxide Research Articles

Synthesis and X-ray Structures of Polymeric Calcium Carboxylates

The reactions of calcium hydroxide with pivalic, 1-naphthoic, and 2-furancarboxylic acids afford the corresponding polymeric calcium carboxylates. Depending on the crystallization conditions, calcium pivalate is isolated as two different coordination polymers: [Ca3(Piv)6(DMF)2]n · 0.635nC6H6 · 0.365nDMF (I) and [Ca(Рiv)(H2O)2.333(DMF)0.666]n · nРiv·0.333H2O (II). The synthesized calcium 1-naphthoate contains coordinated water molecules [Сa(Naph)2(H2O)2]n (III), and calcium furoate [Ca(Fur)2]n (IV) contains no ancillary ligands. The structures of compounds I–IV are determined by X-ray diffraction (XRD) (CIF files CCDC nos. 2342790–2342793, respectively). The structures of compounds I–III are characterized by the 1D polymeric structure, and compound IV is the 3D polymer.

Variation of Packing Densities and Liquid Film Thicknesses in Alkali Solution and Water in Natural Pozzolan Calcium Hydroxide Pastes and Mortars

The characteristic properties of concrete depend on the quality of mortar. In order to improve the properties of hardened concrete, the mortar needs to have good performance. The property of mortar is affected by wet packing density, liquid film thickness, type and quality of binder, gradation of fine aggregates, and binder-to-fine-aggregate ratio. The commonly used alkali solutions to produce polymer mortar and concrete are cursed by carbon dioxide emissions. This study used alkali solution and water to investigate the variation of packing densities and film thicknesses on paste and mortar mixes. of natural pozzolan and calcium hydroxide at a ratio of 75P25CH and standard sand. The standard proctor compaction tools and procedures were adopted to attain the maximum values of packing density of 0.937 for mortar mixed with alkali solution, 0.919 for mortar mixed with water, 0.906 for paste mixed with alkali solution, and 0.829 for paste mixed with water. For the case of film thicknesses, the optimum values obtained were 0.548 μm for mortar mixed with alkali solution, 0.248 μm for mortar mixed with water, 0.398 μm for paste mixed with alkali solution, and 0.09 μm mixed with water. The results indicate that alkali solution produced higher packing density and liquid film thickness than water for both paste and mortar, and the packing density and liquid film thickness increase with the increase of the number of compacting blows with 9 blows to 36 blows. The study recommends the establishment of standard compaction effort and procedure.

Calcium Hydroxide–Phosphate-Modified Fly Ash Enhances the Adsorption and Stabilization of Soil Lead and Cadmium

Calcium Hydroxide–Phosphate-Modified Fly Ash Enhances the Adsorption and Stabilization of Soil Lead and Cadmium

Refusal of Surgical Treatment for Advanced Oral Squamous Cell Carcinoma in a Long-Term Naswar Consumer: A Case Report

Introduction: Oral squamous cell carcinoma (OSCC) is a significant global health concern, primarily associated with tobacco use, including naswar—a smokeless tobacco mixture widely used in South Asia. Naswar is composed of ground tobacco leaves, slaked lime, and occasionally flavoring agents. When mixed with saliva, it releases carcinogenic nitrosamines, nicotine, and other harmful toxins. Despite the well-documented risks, including oral cancer, naswar continues to be used by many. Its harmful effects extend beyond oral health, contributing to heart disease, gastrointestinal issues, and reproductive health problems. It is also associated with mouth lesions, gum disease, and an elevated risk of oral cancers. This study emphasizes the urgent need for targeted global strategies to address naswar-related oral cancers. Case Presentation: This article details the case of a 62-year-old woman with a 40-year history of naswar consumption, who was diagnosed with advanced oral squamous cell carcinoma (SCC) affecting the right side of her face. She was referred to the Maxillofacial Surgery Department of Zahedan University of Medical Sciences. Despite recommendations for surgical intervention, the patient declined treatment following comprehensive consultations with medical professionals. This case highlights the complexities of managing advanced oral SCC in chronic naswar users and underscores the role of patient autonomy in treatment decisions. Conclusions: This case illustrates the challenges in treating advanced oral SCC in long-term naswar users and emphasizes the critical importance of respecting patient autonomy in treatment decision-making.

Analysis of the Effects of Temperature and Treatment Duration on the Resistance of Expansive Soil Improved with Lime in Baghdad, Iraq

Multiple studies have revealed the challenge of constructing infrastructure on expansive soils, including pipelines, roads, or buildings. This predicament stems from the uneven moisture distribution inherent to the specific soil type. Numerous methods, involving the addition of chemicals, have been employed to enhance the properties of clayey soils. This study introduces lime as a cation exchange material and demonstrates its capacity to improve the load-bearing characteristics, rendering it a more favorable option for engineering construction purposes. Lime's reaction with clay minerals and water produces calcium hydroxide, which subsequently reacts with the silica and alumina in the clay to form new compounds that promote stability. Additionally, lime helps reduce the soil's water-holding ability, thereby decreasing its swelling potential. This research will focus on evaluating the influence of temperature and treatment duration on the osmotic pressure behavior of chemically treated expansive clayey soils using lime. The swell meter test was utilized to develop lime-clay samples containing 7% lime by dry weight. These samples were then subjected to compression at temperatures ranging from 20 °C to 40 °C over a period of up to 28 days. The findings indicate that the pozzolanic reaction results in higher compressive strengths when tested at the upper limits of the temperature range in laboratory experiments. Therefore, the combined effects of temperature and curing duration play a positive role in improving the compressive strength of expansive soils.

Impact of Physical Processes and Temperatures on the Composition, Microstructure, and Pozzolanic Properties of Oil Palm Kernel Ash

In recent decades, the global use of ashes derived from agro-industrial by-products, such as oil palm kernel shells, which are widely cultivated in Colombia and other tropical regions of the world, has increased. However, the application of these ashes in engineering remains limited due to their heterogeneity and variability. This study utilized scanning electron microscopy (SEM) to assess the influence of calcination temperatures, ranging from 500 °C to 1000 °C, as well as the physical processes of cutting, grinding, and crushing, on the silica content of the studied ashes. Specifically, the sample labeled M18A-c-m-T600°C-t1.5h-tr1h, which was subjected to a calcination temperature of 600 °C and underwent cutting and grinding before calcination, followed by post-calcination crushing, exhibited the highest silica concentration. Complementary techniques such as X-ray fluorescence (XRF) and X-ray diffraction (XRD), were applied to this sample to evaluate its feasibility as an additive or partial replacement for cement in concrete. XRF analysis revealed a composition of 71.24% SiO2, 9.39% Al2O3, and 2.65% Fe2O3, thus, meeting the minimum oxide content established by ASTM C 618 for the classification as a pozzolanic material. Furthermore, XRD analysis confirmed that the sample M18A-c-m-T600°C-t1.5h-tr1h is in an amorphous state, which is the only state in which silica can chemically react with calcium hydroxide resulting from the hydration reactions of cement, forming stable cementitious products with strong mechanical properties.

Computational Intelligence for Modeling the Rheological Properties of the Developed Hydrated Lime-Based Alkali-Activated Materials

The development of alkali-activated materials (AAMs) has gained attention as a sustainable alternative to Portland cement-based concrete. A key factor in AAM performance is its rheological behavior, which influences workability and pumpability. Accurate prediction of these properties is vital for optimizing mix design. This study introduces a computational framework using ensemble and non-ensemble machine learning (ML) techniques to model the yield stress (YS) and plastic viscosity (PV) of AAMs. A comprehensive dataset from previous experiments was used to train models, including artificial neural networks (ANN), gene expression programming (GEP), decision tree, random forest, adaptive boosting, and gradient boosting. The models achieved R² values exceeding 0.95 and correlation coefficients above 0.97. Error metrics, such as MAPE, MAE, MSE, and RMSE, further validated the models’ generalizability. A parametric analysis showed that a 20% increase in hydrated lime (HL) content raised YS by 350Pa, which is similar to the effect of varying fly ash (FA) from 60% to 100%. A 40% increase in FA and HL content increased PV by 4Pa.s and 25Pa.s, respectively. A 3% rise in sodium silicate led to a 400Pa increase in YS, while a similar increase in sodium hydroxide raised YS by 170Pa and PV by 15Pa·s. Overall, this study provides an effective tool for optimizing AAM mix designs by accurately predicting rheological properties and quantifying the impact of key parameters, contributing to the advancement of sustainable cementitious materials in construction.

Properties of waste brick powder-based artificial fine aggregate and its application in concrete

Shortage of natural fine aggregates (NFAs) and large amounts of construction solid waste have become prominent issues in the construction industry. To deal with these problems, this study aims to utilize waste brick power (WBP) to develop WBP-based artificial fine aggregates (AFAs) by high-speed stirring method. In this study, the effects of different proportions of WBP, waste concrete powder (WCP), fly ash (FA), slag powder (SP), calcium hydroxide (Ca(OH)2) and ordinary Portland cement (OPC) on the mechanism, physical and microscopic properties of AFAs were analyzed. Besides, the mechanical properties of concrete using COM AFAs (i.e. the AFAs containing all aforementioned powders) were measured. The results showed the single particle compressive strengths (SPCSs) of WBP-based AFAs increased with the increasing OPC, SP, FA or Ca(OH)2 contents. The WCP contents had a slight effect on the SPCSs. Compared with the NFAs and recycled fine aggregates (RFAs), the apparent density, the loose and close bulk density of COM AFAs reduced, and the loose and close bulk voidages increased. However, the water absorptions of COM AFAs were larger than NFAs, but less than RFAs. It was due to the generation of hydration products during the preparation of AFAs that filled the pores of AFAs. In addition, it was found that the cubic compressive strength and splitting tensile strength of COM AFA concrete using COM AFAs with 20% OPC content were larger than those of concrete using NFAs and RFAs and COM AFAs with 10% OPC content.

Comparative Study on the Effect of Nano Calcium Hydroxide and Klucel E. as Consolidants Materials for Poly-chromed Wood.

Comparative Study on the Effect of Nano Calcium Hydroxide and Klucel E. as Consolidants Materials for Poly-chromed Wood.

A new strategy for the comprehensive utilization of wastewater from the production of soda ash by sodium sulfate-based ammonia-soda process

The production of soda ash by the ammonia-soda process using carbon dioxide and ammonia for sodium sulfate is an effective method to realize the comprehensive utilization of waste resources of sodium sulfate, but this method produces a large amount of wastewater whose main substances are sodium bicarbonate and ammonium sulfate, which limits the modular industrial application of the production of soda ash by sodium sulfate-based ammonia-soda process(SSA-Process). At present, the main utilization method for the wastewater from the production of soda ash by SSA-Process is evaporation crystallization method to deal with the by-products of sodium sulfate and ammonium sulfate, which is a low-value, complex and energy-consuming process, so is an urgent need for a low-cost, high-value, short-process method to comprehensively utilize wastewater from the production of soda ash by SSA-Process. Based on the application theory of calcium hydroxide (Ca(OH)2) in the traditional ammonia-soda process, this present study systematically investigated the causticization law and mechanism of Ca(OH)2 in a simulated wastewater from the production of soda ash by SSA-Process. On this basis, a new process of Ca(OH)2 segmented causticization was developed to realize the comprehensive utilization of wastewater from production of soda ash by SSA-Process. The results showed that this process enabled a highly efficient ammonia cycle for cost reduction and the production of high purity ultrafine calcium carbonate products and sodium sulfate solids, as well as calcium-based raw material for building materials.

CAN ANTI-OXIDANTS REPLACE CALCIUM HYDROXIDE AS INTRA CANAL MEDICAMENT : AN IN VITRO STUDY

Introduction:Endodontics has several main goals, one of which is disinfecting the root canal system. Even though the bacterial load can be effectively reduced by cleaning, shaping, and using antimicrobial medications, some bacteria still survive and proliferate, leading to reinfection. Herbal alternatives have been introduced to counter the inefficacy, possible side effects, and safety concerns associated with synthetic drugs. Herbal irritants are safe and to contain active ingredients with advantageous physiological effects. So, the aim of the study is to evaluate and compare the antimicrobial efficiency of Antioxidants, i.e., green coffee, Lemon, and Honey with Calcium hydroxide as intra-canal medicaments. Methodology: A total of 156single-rooted teeth were decorated at the cement-enamel junction. The apical part of the roots was sealed with composite resin to prevent leakage, followed by instrumentation up to the F3 Protaper universal rotary system and bacterial inoculation. The samples weredivided into 5 groups based on intracanal medicament used Ca(OH)₂,lemon extract,honey,green coffee extract and saline, respectively. These samples were incubated for 24 hrs at 37°C, and then scrapings from these teeth were collected in a test tube containing BHI broth and incubated for 24 hrs at 37°C. samples were streaked on agar plates and observed for E.Faecalis colonies. The One-way ANOVA and Bonferroni Multiple Comparison tests were used to analyse the data statistically. Results: Calcium hydroxide has shown the highest antimicrobial activity compared to other groups. There is no significant difference between lemon and honey. Green coffee has the least antimicrobial property. Conclusion: Antioxidants have a potential to be used as intracanal medicament if its antibacterial activity could be enhanced.

Multi-scale characterization of lightweight aggregate and superabsorbent polymers influence on autogenous shrinkage and microstructure of ultra-high performance concrete

This study investigates the effects of internal curing agents on the autogenous shrinkage, hydration, and microstructure of ultra-high-performance concrete (UHPC). Lightweight aggregate (LWA) and superabsorbent polymers (SAP) were examined across various dosages as representative internal curing agents. Measurements were taken for the mechanical properties, autogenous shrinkage, and internal relative humidity of the UHPC. The mechanisms of internal curing were analyzed using thermogravimetry, pore structure, and microstructural evaluations. Additionally, porosity and microhardness in the matrix around the fibers and internal curing agents were tested to quantitatively assess their impact on the properties of the UHPC matrix. Results indicate that high dosages of LWA or SAP negatively affect the compressive strength of UHPC. A dosage of 15 % LWA increased flexural strength by 11 %, whereas SAP showed no significant improvement in flexural strength. LWA effectively reduced autogenous shrinkage by 49.4 %-88.8 %, while a SAP dosage of 0.3 % reduced autogenous shrinkage by 82 %. Both LWA and SAP increased porosity by 33.9 %-55.9 %. SAP released water within the matrix, forming voids filled with calcium hydroxide. The interface between LWA and the matrix was dense, with porosity near the LWA and SAP interfaces being 23.5 %-53.9 % and 26.0 %-38.2 % lower, respectively, compared to other areas. The microhardness in the LWA and SAP interface regions was 20 % and 16.2 % higher than in different places. The LWA pre-saturated method can effectively reduce autogenous shrinkage, and 15 % LWA has no adverse effect on mechanical strength.

Controlling root canal infection in oncological patients with apical periodontitis

This study evaluated the effectiveness of chemomechanical preparation associated with intracanal medication in reducing the total bacterial load of infected root canals in cancer patients undergoing antineoplastic treatment. The prevalence, levels and response to treatment of Streptococcus and Actinobacteria species were also assessed. The root canals of teeth with apical periodontitis from oncological and control patients were treated using rotary instrumentation, 2.5% NaOCl irrigation and 1-week calcium hydroxide medication (n=23/group). Bacteriological root canal samples were taken before (S1) and after chemomechanical preparation (S2), and after intracanal medication (S3). DNA extracted from the samples was subjected to 16S rRNA gene-based quantitative real-time polymerase chain reaction assays for evaluation of the treatment effects on total bacteria, Streptococcus species, and members of the Actinobacteria phylum. All S1 samples were positive for bacteria. S1-to-S2 and S1-to-S3 bacterial reduction values were highly significant (p<0.01). Although bacterial counts were reduced from S2 to S3, the decrease was not statistically significant (p>0.05). Intergroup comparisons showed no significant differences in S1, S2 and S3 counts (p>0.05). In the oncological group, 77% of the cases were positive for bacteria in S2, and 68% in S3. In the control group, corresponding figures were 65% for both S2 and S3. There were no significant differences between groups as for streptococci and actinobacteria prevalence, levels and response to treatment (p>0.05). Root canal treatment using rotary instruments, NaOCl irrigation and calcium hydroxide medication was highly effective in reducing the bacterial populations in infected teeth with apical periodontitis from cancer patients, with no significant differences to controls.

Intracanal antibacterial effects of a bioceramic medication compared with calcium hydroxide pastes in different vehicles

The intracanal antibacterial effectiveness of a bioceramic medication was compared with calcium hydroxide pastes in different vehicles. Extracted mandibular incisors with a single long oval canal were selected and distributed into 5 groups based on anatomically paired micro-computed tomographic analyses. The root canals were prepared up to an instrument size 35/04 and contaminated for 30 days with a mixed bacterial culture from subgingival biofilm added with Enterococcus faecalis. The canals were medicated with Bio-C Temp (Angelus Indústria de Produtos Odontológicos, Londrina, PR, Brazil) or a calcium hydroxide paste in glycerin (CHG), camphorated paramonochlorophenol/ glycerin (CHPG), or 2% chlorhexidine (CHCX). Control specimens were filled with sterile saline. After 7 days, the medication was removed by using rotary instruments and saline irrigation. A supplementary approach was conducted, which consisted of 2.5% NaOCl irrigation and agitation with XP-endo Finisher. Bacteriological samples were taken before application (S1) and after removal (S2) of the intracanal medication, and after the supplementary approach (S3). Bacterial DNA extracted from the samples was quantified using real-time polymerase chain reaction. Bacterial counts were significantly reduced from S1 to S2 in all groups, except for the control group. As for S1-to-S3 changes, all groups (control included) showed significant bacterial reduction. S2-to-S3 changes were only significant in the CHPG and CHCX groups (p<0.05). Intergroup comparisons showed no significant differences in S2 (p>0.05), with all medications significantly better than the control (p<0.05). In S3, only the CHPG and CHCX groups showed further significant bacterial reductions. Categorical data analysis showed no intergroup differences (p>0.05). All tested medications significantly reduced the intracanal bacterial counts, with no significant differences between them. Final NaOCl irrigation and agitation using XP-endo Finisher further enhanced disinfection in the CHCX and CHPG groups.

Management of Deep Caries Lesions: A Study among Dentists in the Private Sector of Casablanca, Morocco.

To find out which management methods are preferred by dentists in the private sector of Casablanca for a deep carious lesion or a pulp exposure during carious tissue removal in adult patients. A questionnaire consisting of 25 questions was sent to 300 randomly sampled dentists in Casablanca. Only specialists in conservative dentistry and endodontics and general practitioners were included. There were three clinical scenarios allowing to approach the therapy recommended by each practitioner according to the proposed pulp diagnosis, these three different scenarios were based on preoperative symptomatology: Healthy pulp, reversible pulpitis, and irreversible pulpitis. Data entry and analysis were carried out using Epi7 and the results were statistically analyzed. The survey was answered by 214 dentists,145 women and 69 men. Approximately 74.3% of the respondents always establish a pulp diagnosis before carious tissue removal. Approximately 56.54% use partial carious tissue removal techniques. During pulp exposure, 79.25% of the practitioners opted, respectively, for a direct pulp capping (DPC) in the case of healthy pulp and 46.7% in the case of reversible pulpitis, while no practitioner chose DPC in the case of irreversible pulpitis. In addition, 3.31, 27.83, and 4.23% opted for pulpotomy in cases of healthy pulp, reversible and irreversible pulpitis, respectively. Glass ionomer cement (GIC) and calcium hydroxide (CH) are the materials of choice for dentists in cases of partial caries removal. In the case of DPC, dentists use CH and Biodentine™ in particular. Partial carious tissue removal techniques are not adopted by the majority of dentists. When faced with irreversible pulpitis, most dentists (93.33%) go directly to endodontic treatment in the case of deep carious lesion without pulp exposure. While 204 dentists (95.33%) preferred root canal treatment (RCT) too in the case of deep carious lesion with pulp exposure. The use of bioactive materials should be encouraged in the management of deep caries lesions and pulp exposure, Biodentine™ and MTA were chosen by 96 of the practitioners. Traditionally, the treatment of deep caries has been destructive, with removal of all carious dentin; however, the promotion of biologically based minimally invasive treatment strategies has been recommended to selectively (partially) remove caries and reduce the risk of pulp exposure. How to cite this article: Laslami K, Kharroubi SE, Moudrif M, et al. Management of Deep Caries Lesions: A Study among Dentists in the Private Sector of Casablanca, Morocco. J Contemp Dent Pract 2024;25(8):751-757.

Effects of composite alkaline activator on mechanical properties and hydration mechanism of cemented paste backfill with cement kiln dust

To address the low utilization rate and environmental pollution of mine tailings (MT) and cement kiln dust (CKD), a CKD-based cemented paste backfill (CPB) material was prepared using quicklime (CaO) and sulfate (DH-7) as a composite alkaline activator (CAA), with CKD and slag as the cementitious material and MT as the aggregate. The optimal dosage of the new CAA was determined through unconfined compressive strength (UCS) analysis. The reaction products, pore structure, and cation dissolution ability of CKD-based CPB activated by CAA were investigated, analyzing the mechanism of strength enhancement. The results showed that the CAA enhanced the compressive strength of CKD-based CPB by improving the reactivity of calcium hydroxide. The addition of the CAA led to elevated the dissolution concentration of cations such as Ca and Si within the system, accelerating both the alkali activation reaction rate and the nucleation rate of the calcium aluminosilicate hydrate (C–(A–)S–H) gel. Furthermore, with the increase in CAA content, the pore structure of CKD-based CPB became more complex. Therefore, this study may provide novel insights into the preparation of cost-effective CPB materials with a high CKD content.

Long-Term Outcomes of Vital Pulp Therapy in Deep Carious Lesions Using Bioceramic Materials

ABSTRACT Background: Vital pulp treatment (VPT) is an essential clinical intervention used to maintain the integrity of the tooth pulp in situations with severe carious lesions. Due to their bioactivity, sealing ability, and compatibility with pulp tissues, bioceramic materials have attracted considerable interest. Materials and Methods: This research included a sample of 100 individuals who had acquired deep carious lesions. The participants were randomly allocated into two groups: Group A (n = 50) had ventral prosthetic treatment (VPT) using a bioceramic material, whereas Group B (n = 50) underwent VPT with a traditional calcium hydroxide-based material. Initial, 6 months, 12 months, and 24 months after treatment, clinical and radiographic assessments were conducted. The main outcome measures consisted of dental pulp vitality, lack of discomfort, and radiographic evidence of the development of a hard tissue barrier. Results: By the 24-month follow-up, 92% of the teeth in Group A, which used bioceramic material, retained their pulp vitality, but just 80% of the teeth in Group B, which used calcium hydroxide, did the same. Significantly reduced rates of postoperative discomfort were seen in Group A (10%) compared to Group B (25%). The radiographic examination revealed that 88% of patients in Group A displayed effective creation of a hard tissue barrier, whereas only 72% of cases in Group B exhibited comparable results. Conclusion: The research verifies that bioceramic materials provide better long-term results in vital pulp treatment for severe carious lesions as compared to traditional materials based on calcium hydroxide.

Radiological Outcome of Calcium Hydroxide as A Root Canal Sealer Constituent

Background: The effectiveness of root canal sealers plays a crucial role in the success of endodontic treatments by preventing microbial leakage and promoting periapical healing. This study aimed to compare the radiological outcomes of calcium hydroxide-based sealers and zinc oxide eugenol sealers in treating teeth with periradicular pathosis.Methods: This cross-sectional observational study was conducted at different private clinics, Dhaka, Bangladesh during the period from January 2019 to December 2019. A total of 60 permanent teeth with periradicular pathosis were randomly assigned into two groups: Group 1 (n=30), treated with zinc oxide eugenol sealer, and Group 2 (n=30), treated with calcium hydroxide-based sealer. Clinical evaluations were conducted on days 2 and 7 post-treatment, and radiological evaluations were performed at 3, 6, and 12 months. Data were analyzed using SPSS version 22.Results: The majority of participants were aged 11-30 years, with a higher proportion of males in both groups. Trauma was the leading etiological factor, with maxillary teeth being more frequently affected. Group 2 showed significantly better radiological outcomes, with 80.00% exhibiting reduced periapical pathosis size at 3 months, compared to 26.67% in Group 1 (p &lt; 0.001). At 6 months, 93.33% of Group 2 showed reduced pathosis size, compared to 60.00% in Group 1 (p = 0.002). At 12 months, 96.67% of Group 2 and 83.33% of Group 1 showed reduced pathosis size (p = 0.194). The final success rate was 96.67% in Group 2 and 86.67% in Group 1, with no statistically significant difference (p = 0.353).Conclusion: Calcium hydroxide-based sealers provide superior radiological outcomes compared to zinc oxide eugenol sealers in the treatment of teeth with periradicular pathosis. These findings support the use of calcium hydroxide sealers for enhanced endodontic treatment outcomes.

Clinical Outcome Evaluation of The Effectiveness of Calcium Hydroxide as A Root Canal Sealer Constituent

Background: The objective of this study was to evaluate the clinical outcomes of using calcium hydroxide-containing sealer (Sealapex) compared to zinc oxide eugenol (ZOE) sealer in single-visit root canal treatments.Methods: This cross-sectional observational study was conducted at different private clinics, Dhaka, Bangladesh during the period from January 2018 to December 2018. A total of 60 permanent teeth with periradicular pathosis were selected and randomly assigned into two groups. Group 1 (ZOE group) comprised 30 teeth treated with a ZOE sealer, while Group 2 (Sealapex group) included 30 teeth treated with a calcium hydroxide-containing sealer. Clinical evaluations were performed at 3 months and 12 months post-treatment, with patient complaints recorded and analyzed using SPSS version 22 and Microsoft Excel.Results: Group 2 had a higher proportion of younger participants (40.00% aged 11-20) compared to Group 1 (26.67%). Group 1 had more males (66.67%) compared to Group 2 (56.67%). Trauma was the leading etiological factor in both groups. Maxillary teeth were more frequently affected, with 56.67% in Group 1 and 63.33% in Group 2. Pre-operative pain was higher in Group 2 (90.00%) compared to Group 1 (76.67%). At the 3-month follow-up, percussion pain was more prevalent in Group 1 (76.67%) than in Group 2 (46.67%, p = 0.016). By the 12-month follow-up, percussion pain persisted in 13.33% of Group 1 but was absent in Group 2. Group 2 achieved a 100.00% success rate, significantly higher than Group 1’s 86.67% (p = 0.038).Conclusion: The use of calcium hydroxide-containing sealer (Sealapex) in single-visit root canal treatments resulted in superior clinical outcomes compared to zinc oxide eugenol sealer. These findings suggest that calcium hydroxide-containing sealers offer better pain management and higher long-term success rates, making them a more effective alternative for endodontic treatments. Further research is recommended to confirm these results in broader clinical settings.

Influence of Precursor Particle Size and Calcium Hydroxide Content on the Development of Clay Brick Waste-Based Geopolymers

This study evaluated the effect of precursor particle size and calcium hydroxide (CH) incorporation on the microstructure, compressive strength, and rheological properties of clay brick waste (BW)-based geopolymers. Rheological analyses were used to evaluate the fresh state of the geopolymers. XRD, SEM, and EDS analyses were performed to analyze the microstructure. The results showed that the particle size reduction in BW and the incorporation of CH significantly contributed to obtaining better compressive strength in the geopolymers. Furthermore, the particle size reduction decreased the yield stress, plastic viscosity, and hysteresis area of the geopolymers, while the incorporation of CH promoted the opposite effect. Increasing the CH incorporation content accelerated the geopolymerization reactions and reduced the workability of the geopolymers over time. However, since the milling process is costly, milling BW for 2 h was more efficient from a technical–economic point of view. In addition, the incorporation of CH not only promoted the early hardening of the geopolymers when necessary, but also contributed to the improvement of the compressive strength through matrix densification. Therefore, the results of this study show the definition of more efficient material proportions for geopolymers using waste as an aluminosilicate source.