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In recent years, alternative pulpal therapies targeting dentinogenesis signaling pathways using different peptides have been investigated. The aim of this study was to verify the effectiveness of poly(aspartic acid), pAsp, in dentin regeneration using an animal model. Methods: Mechanical pulp exposure was performed in the upper molars of 56 Wistar rats, randomly divided as follows (n = 14): control (no treatment); MTA group—pulp capping with mineral trioxide aggregate (MTA Angelus); pAsp group—application of 20 μL of pAsp solution (25 mg·mL−1); MTA+pAsp group—application of MTA mixed with pAsp (5:1 by mass). Animals were euthanized after 7 or 21 days. Histological sections were submitted to hematoxylin-eosin and Brown and Brenn staining and immunohistochemical analysis for osteopontin (OPN) and dentin matrix protein 1 (DMP 1). Results: At 7 days, an acute inflammatory infiltrate and the presence of disorganized mineralized tissue were observed in all groups. At 21 days, the quality and thickness of the reparative dentin in treated groups were superior to the control, and bacterial contamination was observed in two MTA-pAsp specimens. While all treated groups showed intense immunostaining for OPN at 21 days, only the pAsp group expressed DMP 1, indicating the presence of fully differentiated odontoblast-like cells. Conclusion: Poly(aspartic) acid promoted dentin regeneration in rat molars in the absence of an additional calcium source and may be an alternative to MTA as a pulp-capping agent. [ABSTRACT FROM AUTHOR]

We investigated three calcium silicate-based sealers with respect to their chemical characterization, cytotoxicity, and attachment to RAW264.7 cells. BioRoot RCS (BR), Bio-C Sealer (BC), and Sealer Plus BC (SPBC) were assessed using Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence spectroscopy (XRF), and energy-dispersive X-ray spectroscopy (EDX) (n = 4) for elemental characterization, and using scanning electron microscopy (SEM) to evaluate cell morphology and adhesion. Cytotoxicity was determined at different dilutions (1:1, 1:2, and 1:5) using the succinate dehydrogenase activity (MTT assay). Statistical analysis was performed for normal distribution using the Shapiro–Wilk test and for homoscedasticity using Levene's test, and one-way ANOVA, Tukey's/Dunnett's post hoc tests for cell viability and XRF (α = 0.05). Calcium silicate hydrate and calcium hydroxide were detected by FTIR in all groups. EDX detected a higher calcium content for BR and SPBC and aluminum only in the premixed sealers. XRF detected the highest calcium release in BR (p < 0.05). The surface morphology showed irregular precipitates for all the sealers. SPBC at a 1:2 dilution resulted in the lowest cell viability compared to BR (p < 0.05) and BC (p < 0.05). The calcium silicate-based sealers produced a statistically significant reduction in cellular viability at a 1:1 dilution compared to the control group (p < 0.0001). All the sealers maintained viability above 70%. [ABSTRACT FROM AUTHOR]

A pot experiment was conducted to investigate the effects of silicon (Si) on morpho-physiological and bio-chemical traits of maize under different irrigation regimes. Experimental treatments comprised of irrigations [60% and 100% of field capacity (FC)], treatments (0, 50, 100, 150, 200 mg kg−1 CaO4Si) and growing stages (GS) [7th (first) and 14th (second) days of water restriction]. 150 mg kg−1 Si increased the growth of maize by inducing transpiration rate (67.56%), water use efficiency (138.36%) and seedling length (19.83%) at first GS whilst enhanced carotenoids (10.95%), total phenolic compounds (45.04%) and decreased proline (7.87%) at the second GS of 60% treatment. In addition, 200 mg kg−1 Si elevated photosynthesis rate (40.54%), total antioxidant activity (12.69%) and decreased proline (52.77%) at the first GS while increased total anthocyanin content (14.99%) during the second GS of 60% application. Silicon had positive impacts on maize under full irrigation conditions too such that 150 mg kg−1 Si reduced transpiration rate (48.43%) and induced total antioxidant activity (39.95%) at first GS while 200 mg kg−1 Si increased water use efficiency by 144.30% at the second GS. In conclusion Si increased drought resistance due to increasing application doses, and on contrary of the literature, Si positively affected many characters at well-watered environment. [ABSTRACT FROM AUTHOR]

This study disclosed the synthesis and characterization of externally and/or internally crosslinked alginate‐gellan gum composite interpenetrating polymer networks (IPN) and IPN hydrogel microspheres for controlled delivery of gliclazid. The internal cross‐linking of the polymer sol was accomplished via slow release of Ca2+ ions from calcium silicate in presence of gluconic acid d‐lactone. The microspheres had spherical shape with smooth surface morphology. The IPN or composite IPN hydrogel microspheres had drug entrapment efficiency of 70%–76%. Incorporation of gellan gum or gellan gum/calcium silicate in the alginate sol sustained the release of drug in simulated gastrointestinal fluids over 12 h without any sign of particle disintegration. Inclusion of calcium silicate in alginate gels was ineffective in controlling drug release under simulated gastrointestinal milieu. The drug release obeyed anomalous diffusion mechanism after inclusion of gellan gum or gellan gum‐calcium silicate in the alginate gel microspheres. Fourier‐transform infrared (FTIR) spectroscopy and zeta analysis confirmed absence of drug‐polymer chemical interaction. The thermal and x‐ray diffraction analyses suggested that the drug transformed into amorphous state after incorporation into composite hydrogel system. Hence, it may be advantageous to combine internal and external gelation procedures for creating composite IPN or IPN hydrogel microspheres for avoiding burst effect of alginate microspheres and managing desired drug release patterns in vitro. [ABSTRACT FROM AUTHOR]

Whey protein isolate (WPI) hydrogels are attractive biomaterials for application in bone repair and regeneration. However, their main limitation is low mechanical strength. Therefore, to improve these properties, the incorporation of ceramic phases into hydrogel matrices is currently being performed. In this study, novel whey protein isolate/calcium silicate (WPI/CaSiO3) hydrogel biomaterials were prepared with varying concentrations of a ceramic phase (CaSiO3). The aim of this study was to investigate the effect of the introduction of CaSiO3 to a WPI hydrogel matrix on its physicochemical, mechanical, and biological properties. Our Fourier Transform Infrared Spectroscopy results showed that CaSiO3 was successfully incorporated into the WPI hydrogel matrix to create composite biomaterials. Swelling tests indicated that the addition of 5% (w/v) CaSiO3 caused greater swelling compared to biomaterials without CaSiO3 and ultimate compressive strength and strain at break. Cell culture experiments demonstrated that WPI hydrogel biomaterials enriched with CaSiO3 demonstrated superior cytocompatibility in vitro compared to the control hydrogel biomaterials without CaSiO3. Thus, this study revealed that the addition of CaSiO3 to WPI-based hydrogel biomaterials renders them more promising for bone tissue engineering applications. [ABSTRACT FROM AUTHOR]

Bioceramic cements used for filling root canals in cases of endo-perio lesion of endodontic origin seem to be promising due to having the potential of promoting faster and more predictable healing of the periapical lesion as they stimulate osteogenesis. An effective treatment plan depends on the precise diagnosis of endo-perio lesions. The origin of an infection, being exclusive to the root canal, from the periodontium, or both, is extremely important for devising the treatment plan. In both cases, no clinical evidence of periodontal disease (bleeding, calculus, etc.) was found; however, primary endodontic lesions with the possibility of drainage through the gingival crevice were present. In addition to the disinfection strategies used during the root canal treatments, the bioceramics Bio C Sealer, Bio C Repair and Bio Root RCS were used to fill in the root canals. Both cases presented an impressive bone gain within 8 months for case 1 and 5 months for case 2. Regarding case 1, in the palatal root canal an apical plug with a bioceramic repair cement was used. Based on the literature studied, it can be concluded that after adequate disinfection of the root canals, using bioceramic cements in filling the root canals shows the potential of supporting capabilities in remineralization of osteolytic lesions in endo-perio diseases. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to compare the effect of ultrasonic activation (UA) on tubular penetration between Bio-C Temp and Ultracal XS intracanal medicaments. Methods: Forty single-rooted human premolars were endodontically prepared and divided into 4 experimental groups (n=10): Bio-C Temp, Bio-C Temp+UA, UltraCal XS and UltraCal XS+UA. All medicaments were previously mixed with a specific calcium marker (Fluo-3) and passively injected into the canals. The samples were incubated for 7 days. For each tooth, 1 mm thick sections were obtained from the middle and apical thirds of the canals. The samples were examined by confocal laser scanning microscopy (CLSM) and the depth and area of penetration were determined for each group. The Student t test was used to compare results between groups (p<0.05). Results: UA increased the depth and penetration area of Bio-C Temp and Ultracal XS, showing significant differences in the penetration area of the apical third for Bio-C Temp (p<0.0339). Bio-C Temp presented greater tubular penetration than Ultracal XS, showing significant differences in the depth of penetration in the apical third (p<0.0005), and in the penetration area in the middle (p<0.0016) and apical third (p<0.0339) after UA. Conclusion: UA increases tubular penetration (both depth and area) of Bio-C Temp at the apical third but has no significant effect on Ultracal XS. Bio-C Temp has a greater depth and tubular penetration area than Ultracal XS after UA. [ABSTRACT FROM AUTHOR]

Driven by the urgent need for a solution to tackle the surge of rice husk (RH) and waste frying oil (WFO) waste accumulation at a global scale, this report highlights the use of calcium silicates (CS) extracted from acid-pre-treated rice husk ash (RHA) for free fatty acid (FFA) removal from WFO as conventional RHA shows limited FFA adsorption performance. A novel alkaline earth silicate extraction method from acid-pre-treated RHA was outlined. The structural and behavioural attributes of the synthesised CS were identified through BET, SEM-EDS, and XRD analyses and compared to those of RHA. Notable morphology and structural modification were determined, including reducing specific surface areas, mitigating from amorphous to crystalline structure with regular geometric forms, and detecting Si–O–Ca functional groups exclusive to CS adsorbents. A comparison study showed superior lauric acid (LA) adsorption performance by CS absorbents over acid-pre-treated RHA, with a significant increase from 0.0831 ± 0.0004 mmol LA/g to 2.5808 ± 0.0011 mmol LA/g after 60 min. Recognised as the best-performing CS adsorbent, CS-1.0 was used for further investigations on the effect of dosage, LA concentration, and temperature for efficient LA adsorption, with up to 100% LA removal and 5.6712 ± 0.0016 mmol LA/g adsorption capacity. The adsorption isotherm and kinetic studies showed LA adsorption onto CS-1.0 followed Freundlich isotherm with KF = 0.0598 mmol(1-1/n) L(1/n) g−1 & Qe,cal = 3.1696 mmol g−1 and intraparticle diffusion model with kid = 0.1250 mmol g−1 min0.5 & Ci = 0.9625 mmol g−1, indicating rapid initial adsorption and involvement of carboxylate end of LA and the calcium ions on the CS-1.0 in the rate-limiting step. The high equilibrium adsorption capacity and LA adsorption rate indicated that the proposed CS-1.0 adsorbent has excellent potential to recover FFA from WFO effectively.

Salinity is known to have a greater impact on shoot growth than root growth. Na+ buildup in plant tissue under salt stress has been proposed as one of the main issues that causes growth inhibition in crops via ionic imbalances, osmotic stress and pH disturbances. However, the evidence for apoplastic Na+ buildup and the role of silicon in Na+ accumulation at the subcellular level is still enigmatic. The current study focuses on the accumulation of Na+ in the apoplast and symplast of younger and older leaves of two maize varieties (Iqbal as salt-tolerant and Jalal as salt-sensitive) using hydroponic culture along with silicon supplementation under short-term salinity stress. Subcellular ion analysis indicated that silicon nutrition decreased Na+ concentration in both apoplastic washing fluid and symplastic fluid of maize under salt stress. The addition of silicon under NaCl treatment resulted in considerable improvement in fresh biomass, relative water content, chlorophyll content, and concentration of important subcellular ions (i.e., Ca2+, Mg2+, and K+). Knowledge of subcellular ion analysis is essential for solving the mechanisms underlying vital cellular functions e.g. in the current study, the soluble Na+ concentration in the apoplast of older leaves was found to be significantly greater (36.1 mM) in the salt-sensitive variety under NaCl treatment, which was 42.4% higher when compared to the Na+ concentration in the salt-tolerant variety under the same treatment which can influence permeability of cell membrane, signal transduction pathways and provides insights into how ion compartmentalization can contributes to salt tolerance. Calcium silicate enrichment can contribute to increased growth and improved ionic homeostasis by minimizing leaf electrolyte leakage, improving mechanical functions of cell wall and reducing water loss, and improved photosynthetic function. In current investigation, increased water content and intracellular ionic homeostasis along with reduced concentration of Na+ in the maize leaf apoplast suggest that calcium silicate can be used to ameliorate the adverse effects of salt stress and obtain yield using marginal saline lands.

Background/purpose: Recently introduced calcium silicate-based bioceramic (CSBC) sealers require moisture for setting, thus this study aimed to compare the setting times of epoxy resin-and CSBC sealers under different test conditions. Materials and methods: Four CSBC sealers (CeraSeal, EndoSeal TCS, One-Fil, and Well-Root ST) were compared to an epoxy resin-based sealer (AH Plus). Each sealer was placed in a stainless-steel and gypsum molds on a glass slide. Sealer samples (n = 10 per group) were stored in an incubator at 95% humidity and 37 °C. A Gilmore needle with a total weight of 100 g and a 2.0-mm diameter were carefully placed vertically against the sealer, and the setting time was recorded when the needle no longer formed an indentation on the sealer surface. Statistical analysis was performed using two-way analysis of variance and Tukey parametric tests. The level of significance was set at 95%. Results: The setting time of all sealers in gypsum molds was significantly shorter than that in stainless-steel molds (P

Effective root canal disinfection and the subsequent release of natural growth factors from dentin are crucial to the success of regenerative endodontic procedures. This study evaluated the effect of newly introduced calcium silicate-based temporary intracanal medicament Bio-C Temp and calcium hydroxide-based material UltraCal XS on the release of transforming growth factor β1 (TGF-β1) from root canal dentin. Twenty-two intact and fully developed human premolars from patients aged 15–18 were shaped and irrigated according to the current clinical recommendations. The teeth were then gently split in half, and the root canal dentin of paired samples was covered with Bio-C Temp or UltraCal XS. After 3 weeks of incubation, the specimens were conditioned with 17% EDTA and the collected solution was subjected to the quantification of the released TGF-β1 by performing an ELISA. One-way analysis of variance (ANOVA), followed by Tukey’s test, was selected to determine the statistically significant differences between the groups at the 0.95 confidence level. The highest mean value of released TGF-β1 (1993.1 pg/mL) was detected in the control group, where the root canal dentin was conditioned with 17% EDTA alone. Regarding the experimental groups, Bio-C Temp released a statistically significantly higher amount of TGF-β1 (282.14 pg/mL) compared to UltraCal XS (114.28 pg/mL; p = 0.0158). Bio-C Temp affected the release of growth factors from root canal dentin less than UltraCal XS and may therefore serve as an intracanal medicament for regenerative endodontic procedures.

We investigated the reaction kinetics and initial chemical conditions in the production of silicon alloys, employing aluminum as the reductant for calcium silicate slag, to enhance process economics and scalability to industrial levels. The apparent kinetics and transient chemical conditions were studied by immersing solid aluminum into molten slag, allowing the reaction to proceed for varying durations without external agitation, before quenching the reaction for chemical and microscopic analyses of the resulting silicon alloy and slag. The majority of the conversion was observed within the first 15 s at 1650 °C, driven by significant chemical interactions and interfacial turbulence introduced upon aluminum immersion. For Al-SiO2 stoichiometries ranging from 0.5 to 1.2, the slag phase reaction conformed to first-order kinetics during the initial two minutes, when it approached equilibrium. The mass transfer coefficients for Al2O3 were estimated at 1–2 × 10−4 m/s, comparable to those for SiO2 and CaO. A constant mass transfer coefficient could not be established for stoichiometries of 1.6 and 2, as these deviated from the standard slag mass transfer relationship and did not adhere to established relationships. Despite near-complete reactions, alloy–slag mixing was extensive, decreasing with lower stoichiometry values.

This study aimed to examine how heating affects the physical properties of a newly developed premixed calcium silicate-containing sealer (AH Plus Bioceramic Sealer; AHB), in comparison with EndoSequence BC Sealer (ES), AH Plus Jet (AH), and Pulp Canal Sealer. The setting time, flow, and film thickness were tested with or without heating at 100 °C for 30 or 60 s, in accordance with ISO6876:2012 standards. Ultrastructural and elemental analyses were performed with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Data were analyzed using one-way analysis of variance (ANOVA) with a Tukey post hoc test (α = 0.05). All sealers exhibited significantly shorter setting time and flow after heating at 100 °C for 30 and 60 s (p < 0.05). After heating, AHB showed a significantly higher film thickness compared to that of the other materials (p < 0.05). None of the tested properties of heat-applied AHB and ES met ISO standards, except the setting time in ES. The SEM/EDS results for AHB and ES were not affected by heating. The detected changes in physical properties can negatively impact the performance of premixed calcium silicate-containing sealers, particularly AHB, when warm vertical compaction is employed.

Abstract Orthopedic implant coatings with optimized surface topography and chemistry can achieve favorable osteogenesis and inflammatory responses. In this work, to take advantage of micro/nano-topography and nutrient element Mg, atmosphere plasma spray and hydrothermal treatment were employed to fabricate two kinds of Mg-incorporated micro/nano-topographical calcium silicate coatings with 0.9 and 15.7 wt% Mg content (Mg1-CS and Mg2-CS). MgSiO3 microspheres composed of nano-flakes were formed on the CS coating surface. We investigated the effects of surface topography and released Mg ion on the protein adsorption and the behaviors of bone mesenchymal stem cells (BMSCs) and RAW264.7 macrophages. Compared with the CS coating, the Mg2-CS coating had 1.8-fold increase in specific surface area, which favored serum protein adsorption and BMSC adhesion. With higher Mg2+ release, the Mg1-CS coating exerted greater effect on enhancing fibronectin adsorption, integrin activation, and osteogenic behaviors of BMSCs. The gene expression profiles showed that the Mg-incorporated CS coatings could modulate macrophage polarization towards M2 phenotype with Mg2-CS showing greater effect. These results showed that the nanostructured Mg-containing surface can promote osteogenic responses and mitigate inflammatory reactions.

This study investigates the thermodynamic and mechanical properties of two common calcium silicate phases, xonotlite (Ca6Si6O17(OH)2) and wollastonite (CaSiO3), in high temperature geothermal well cement using first-principles methods. Various properties, including thermal expansion coefficients, elastic constants, free energy, and entropy, were evaluated with the use of accurate anharmonic approximations at high temperatures. The study found that wollastonite has higher mechanical strength (97 GPa) compared to xonotlite (66 GPa) and lower thermal expansion, with decreasing values at higher temperatures. Volumetric thermal expansion coefficients were also calculated at different temperatures. These results demonstrate the potential of wollastonite as a suitable material for high-temperature cement dehydration processes.

Critical-size bone defects of complex geometries are challenging to repair, making current approaches less satisfactory. Although calcium silicate (CaS) scaffolds prepared using 3D printing can be promising, these scaffolds are commonly treated with harsh conditions to reinforce their strength, significantly affecting the activity of biomolecules in the scaffolds. In this study, we developed a novel CaS biomaterial ink that did not require harsh post-treatments. It is shown that the printability was significantly improved using polyethylene glycol (PEG) and pluronic F-127 (PF), and the scaffolds showed excellent shape fidelity after printing. Moreover, the scaffolds demonstrated compatible mechanical strength with trabecular bone (∼7.07 MPa vs. 0.6 ∼ 16.8 MPa), and adding teriparatide (TP) in scaffolds could further improve the scaffold's potential for bone tissue engineering. [Display omitted] [ABSTRACT FROM AUTHOR]

Aim: This study aimed to evaluate the volumetric change of root canal sealers through micro‐computed tomographic analysis using a novel in vivo model and to compare the results with those obtained using an ex vivo test. Methodology: Eighteen single‐rooted teeth were cut to 5 mm length from the root apex. The root canals were uniformly enlarged and filled with EndoSequence BC Sealer or AH Plus Jet root canal sealers. Samples were stored at 37°C and 95% relative humidity for 24 h and then scanned with a micro‐CT device. Twelve samples (n = 6 for each sealer) were implanted in the subcutaneous tissue of Wistar rats, while six samples (n = 3 for each sealer) were immersed in 20 mL of phosphate‐buffered saline (PBS) at 37°C at neutral pH. After 7 and 30 days, teeth were removed from subcutaneous tissue or PBS and rescanned. Statistical analysis of volume changes was performed using Shapiro–Wilk's test and independent t‐test (p <.05). Results: AH Plus Jet had smaller volume changes (−2.2 to +0.77%) than EndoSequence BC Sealer (−2.0 to +4.0%) (p <.05), in the two tested models. The volume of the root canal sealers decreased over time (p <.05), in vivo. AH Plus Jet results varied between the in vivo and ex vivo results (p <.05), while EndoSequence BC Sealer presented similar volume losses for both experimental models (p >.05). Conclusion: EndoSequence BC Sealer lost more volume than AH Plus Jet. The experimental conditions influenced the volumetric change of AH Plus Jet but not the EndoSequence BC Sealer. The ex vivo model should be further explored as a methodological alternative to assess the volumetric changes of root canal sealers without causing harm to animals. [ABSTRACT FROM AUTHOR]

This study aims to formulate metronidazole liquid nanocapsules (MTZ LNC) and evaluate their effect on the physicochemical and biological properties of calcium silicate-based bioactive endodontic cements, in vitro. A MTZ LNC suspension was formulated by deposition of the preformed polymer and characterized by laser diffraction and high-performance liquid chromatography (HPLC). Calcium silicate (CS) was mixed with a radiopaque agent (calcium tungstate - CaWO 4), at 10 wt%, to produce the cement powder. Cements liquids were used with two concentrations of MTZ LNC suspension: 0.3 mg/ml and 0.15 mg/ml. Cements prepared with distilled water were used as the control. The radiopacity, setting time, and flow were evaluated following ISO 6876:2012. The compressive strength analysis was conducted according to ISO 9917:2007. pH and mineral deposition were evaluated after immersion in simulated body fluid (SBF). Cell behavior was evaluated by the viability of pre-osteoblastic cells and pulp fibroblasts by SRB and MTT and the antibacterial activity against Enterococcus faecalis was analyzed immediately and after nine months of water storage. MTZ LNCs were formulated with a median diameter of 148 nm and 83.44 % load efficiency. Increased flow and reduced strength were observed for both MTZ LNCs concentrations. The incorporation of MTZ LNCs maintained the ability of cements to increase pH media and promote mineral deposition over the samples, without promoting cytotoxicity. A 2 log 10 reduction in E. faecalis CFU was observed immediately and after nine months in water storage. The formulation of MTZ LNCs allowed the development of antibacterial calcium silicate-based-cements with suitable physicochemical properties and bioactivity, with a reduction in mechanical strength. The 0.3 mg/ml concentration in cements liquid promoted effective and sustainable antibacterial activity. [Display omitted] • Metronidazole liquid nanocapsules (MTZ LNC) were formulated with high-drug load. • MTZ LNC was applied as the liquid for the calcium silicate hydration reaction. • Cements with MTZ LNC addition presented suitable physicochemical behavior. • -Cytotoxicity was limited by the encapsulation of MTZ. • -Antibacterial activity was observed immediately and after 9 months of aging. [ABSTRACT FROM AUTHOR]

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

To evaluate the effect of the photodynamic therapy (PDT) using with different photosensitizers on the bond strength of BioRoot RCS (BR) to radicular dentin by comparing with AH Plus (AH). The shaped root canals of 80 human mandibular premolars were divided into four groups based on the final disinfection protocol: NaOCl/EDTA, PDT with methylene Blue (MB), PDT with curcumin (CUR) and PDT with toluidine blue O (TBO) (n = 20). Each group was randomly divided into two subgroups (n = 10), according to the endodontic sealer used for obturation (n = 10). The test of push‐out bond strength (PBS) was performed using an universal test machine. The data were analysed using ANOVA, Tukey post‐hoc, and independent sample t‐test (α = 0.05). MB‐BR group showed the highest PBS at the cervical level (p < 0.05). The selection of the photosensitizer in PDT influenced adhesion of root canal sealers to radicular dentin. [ABSTRACT FROM AUTHOR]

This study assessed the influence of pH variation on the volumetric change of EndoSequence BC Sealer compared to AH Plus Jet. Eighteen single‐rooted teeth were uniformly prepared and filled with one of the sealers. After 24‐h storing, samples were scanned in a micro‐CT device. Then, roots were immersed in 20 ml phosphate‐buffered saline (PBS) with pH of 5, 7 or 12 at 37°C for 7 and 30 days and rescanned. Statistical analysis was performed using Shapiro–Wilk's test, one‐way ANOVA and Tukey's or Student's t‐tests (p < 0.05). Differences between sealers were observed only at neutral pH and after 30 days of acidic pH exposure, with a higher loss of EndoSequence (p < 0.05). After 7 days, alkaline pH reduced and increased the volumetric loss of EndoSequence and AH Plus, respectively, compared to neutral pH (p < 0.05). It can be concluded that the pH directly influenced the volumetric change of both tested root canal sealers in different ways. [ABSTRACT FROM AUTHOR]

The aim of the present study was to compare the physico‐chemical properties of EssenSeal with AH PLUS bioceramic and Pulp Canal Sealer EWT. Flow, solubility, film thickness, radiopacity and setting time were evaluated according to ISO 6876 (2012) specifications. External and cross‐section surface characteristics were analysed under a scanning electron microscope. Statistical analysis was performed using Shapiro–Wilk's test, one‐way ANOVA and the Tukey HSD test. All the sealers conformed to the ISO 6876 (2012) standards, except for the setting time for AH plus bioceramic, which exceeded more than 10% of the time indicated by the manufacturer. Statistically significant differences were found between the three study sealers regarding the physico‐chemical properties tested (p < 0.05). EssenSeal demonstrated characteristics respecting the ISO 6876 (2012) standards and can be considered a predictable alternative in root canal sealing. [ABSTRACT FROM AUTHOR]

The increasing requirement and use of dental implant treatments has rendered dental implantology indispensable in dentistry. The aim of this study is to determine the optimum concentration of calcium silicate to be incorporated into a polyetherketoneketone (PEKK) matrix used as an implant material to enhance the bioactivity and mechanical properties of the composite compared with unmodified PEKK. In this study, different weight percentage (wt%) of micro-calcium silicate (m-CS) is incorporated into PEKK with ethanol as a binder. Subsequently, the mixture is dried in a forced convection oven at 120°C and poured into customized molds to fabricate a bioactive composite via compression molding (310°C, 15 MPa, and 20 min holding time) (n = 5). The mechanical properties and in vitro apatite-forming ability of the composites are investigated. Although an apatite layer is formed on all composites after immersion in simulated body fluid for 7 days, the flexural strength and elastic modulus of the composite increased after the filler load is increased to 15 wt%, whereas it decreased in groups with filler loadings exceeding 15 wt%. The results of this study indicate that the incorporation of 15 wt% m-CS into the PEKK polymeric matrix can improve the bioactivity and mechanical properties of this bioactive composite. [ABSTRACT FROM AUTHOR]

This study investigated the role of aging and changes in environmental conditions on selected properties of a prototype radiopacified calcium silicate‐based cement (TZ‐base) with or without incorporation of silver nanoparticles or bioactive glass, and two commercial materials, Biodentine and intermediate restorative material. Materials were immersed in ultrapure water or fetal bovine serum for 28 days and were characterized with scanning electron microscopy and energy dispersive x‐ray analysis. Immersion media were either replaced weekly or not replenished at all and were assessed for alkalinity and calcium release after 1, 7, 14, 21, and 28 days; antibacterial effect against 2‐day monospecies biofilms; and cytotoxicity by the 3‐(4,5 dimethylthiazolyl‐2‐yl)‐2,5‐diphenyl tetrazolium bromide assay after 1, 7, or 28 days. Alkalinity, calcium release, antibacterial activity, and cell cytotoxicity increased over time when the medium was not changed but decreased with medium replenishment. Immersion in fetal bovine serum resulted in lower alkalinity, less bactericidal properties, and lower cytotoxicity of prototype cements and Biodentine than did water immersion. Biodentine and 20% bioactive glass‐containing cement had overall lower alkalinity, calcium release, and antibacterial activity than TZ‐base, and Biodentine was less cytotoxic than TZ‐base. In conclusion, exposure conditions and cement modifications significantly affected materials' leaching properties. Exposure conditions warrant consideration when evaluating cements' clinical properties. [ABSTRACT FROM AUTHOR]

The central objective of this research was to examine the color consistency of three materials, Biodentine (Septodont, France), Angelus MTA (Angelus, Brasil), and BIOfactor MTA (Imicryl, Turkey), when exposed to various irrigation solutions and to observe their impact on tooth discoloration. Each material was used to make sample cylinders (n = 18). After hardening, the samples were immersed for 24 h in either distilled water, 2.5% sodium hypochlorite (NaOCl), or 2% chlorhexidine gluconate (CHX). A spectrophotometer was used to measure the color changes. On the mandibular molars, access cavities were made in order to assess the discoloring impact of calcium silicate cements. In the pulp chambers of the teeth, Biodentine, Angelus MTA, and BIOfactor MTA were inserted (n = 17). Glass ionomer cement was used to seal the samples. Spectrophotometric measurements were made at five different intervals (the beginning, one week, one month, three months, and six months), after which color variance values were computed. The resulting information was statistically evaluated. In all solutions, Biodentine and BIOfactor MTA displayed similar ΔE values. When Angelus MTA was soaked in NaOCl, it discolored more than in CHX or distilled water. Distilled water and NaOCl both caused identical discoloration on all material groups when solutions were examined separately. With CHX, Biodentine changed colors more significantly. After a week and a month, all substances caused comparable tooth discoloration. Biodentine produced the most significant color shifts on teeth at the third and sixth months. Angelus MTA exhibited less color stability in NaOCl and Biodentine in CHX. While Biodentine induced significant discoloration, BIOfactor MTA only showed a moderate amount. [ABSTRACT FROM AUTHOR]

The strength of the structure of iron ore pellets is one of the conditions for their successful transportation from manufacturer to consumer. Among the analyzed aspects of the formation of the pellet structure is the formation of calcium silicates (pyroxene-olivine series) in the mineral part of the cake, the influence of which is associated with a polymorphic transformation upon cooling, a change in the geometry of the crystals and an increase in internal stresses. The purpose of this work is to quantitatively assess the influence of this factor on the strength of pellets from highly enriched concentrates. A mathematical model and experimental data were used for the study. The obtained results confirm that when switching to the use of concentrates "rich" in iron, the role of the silicate binder in the formation of the strength of pellets decreases and the "ore mineral-ore mineral" type binder becomes more important. The probability of the formation of calcium silicates decreases when the silicon oxide content in the pellets is reduced from 6 to 3% (abs.). Accordingly, the negative impact of flux additives on strength due to softening of the structure will be reduced: the less calcium silicates in the structure, the lower the internal stresses in the cake during crystallization. The strength of pellets with increasing degree of concentrate enrichment is determined to a greater extent by the sintering of iron oxides than by the strength of the silicate binder. This, in turn, creates a request for the search for technical solutions to intensify the solid-phase sintering stage, optimal use of the free energy of the concentrate surface, and the formation of raw pellets with a uniform structure without defects (cracks, cavities, etc.). An increase in the probability (proportion) of the formation of calcium silicates for every 10% (rel.) leads to a decrease in the strength of the pellets by 0.8–2.03 daN, or by 3–8% (rel.). [ABSTRACT FROM AUTHOR]

There are still limitations in artificial bone materials used in clinical practice, such as difficulty in repairing large bone defects, the mismatch between the degradation rate and tissue growth, difficulty in vascularization, an inability to address bone defects of various shapes, and risk of infection. To solve these problems, our group designed stereolithography (SLA) 3D-printed calcium silicate artificial bone improved by a calcium sulfate-Cu2+ delivery system. SLA technology endows the scaffold with a three-dimensional tunnel structure to induce cell migration to the center of the bone defect. The calcium sulfate-Cu2+ delivery system was introduced to enhance the osteogenic activity of calcium silicate. Rapid degradation of calcium sulfate (CS) induces early osteogenesis in the three-dimensional tunnel structure. Calcium silicate (CSi) which degrades slowly provides mechanical support and promotes bone formation in bone defect sites for a long time. The gradient degradation of these two components is perfectly matched to the rate of repair in large bone defects. On the other hand, the calcium sulfate delivery system can regularly release Cu2+ in the temporal and spatial dimensions, exerting a long-lasting antimicrobial effect and promoting vascular growth. This powerful 3D-printed calcium silicate artificial bone which has rich osteogenic activity is a promising material for treating large bone defects and has excellent potential for clinical application.

The development of surface modification techniques has brought about a major paradigm shift in the clinical applications of bone tissue regeneration. Biofabrication strategies enable the creation of scaffolds with specific microstructural environments and biological components. Lithium (Li) has been reported to exhibit anti-inflammatory, osteogenic, and chondrogenic properties by promoting several intracellular signaling pathways. Currently, research focuses on fabricating scaffolds with simultaneous dual bioactivities to enhance osteochondral regeneration. In this study, we modified the surface of calcium silicate (CS) scaffolds with Li using a simple immersion technique and evaluated their capabilities for bone regeneration. The results showed that Li ions could be easily coated onto the surfaces of CS scaffolds without affecting the microstructural properties of CS itself. Furthermore, the modifications did not affect the printing capabilities of the CS, and porous scaffolds could be fabricated via extrusion. Moreover, the presence of Li improved the surface roughness and hydrophilicity, thus leading to enhanced secretion of osteochondral-related regeneration factors, such as alkaline phosphatase (ALP), bone sialoprotein (BSP), and collagen II (Col II) proteins. Subsequent in vivo studies, including histological and micro-CT analyses, confirmed that the Li-modified CS scaffolds promoted osteochondral regeneration. The transcriptome analysis suggested that the enhanced osteochondrogenic capabilities of our scaffolds were influenced by paracrine exosomes. We hope this study will inspire further research on osteochondral regeneration.

In this study, amorphous ZnO-containing calcium silicate nano powders were prepared by sol–gel technique and then calcined at different temperatures; namely, 600, 800 and 1000 °C, to study their crystallization. The synthesized powders were examined by X-ray diffraction (XRD) technique, Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). Then, the synthesized powders were sintered at different temperatures. The sintered ceramics were examined for their physical properties, microstructure, mechanical properties and electrical properties by the suitable techniques. The results revealed that the synthesized nano powders were amorphous even after calcination up to 800 °C. By increasing the calcination temperature into 1000 °C, crystalline calcium silicate ceramic was formed. The average particle size of this crystalline material was 50 nm with lower agglomeration among the others calcined at low temperatures. Regarding to the sintered ceramics, the bulk density, fracture toughness and electrical conductivity were increased with increasing both sintering temperature and zinc content. On the other hand, microhardness, compressive strength, elastic moduli and Poisson's ratio were increased with increasing sintering temperature and decreased with increasing the zinc content. [ABSTRACT FROM AUTHOR]

Objectives: This study is to evaluate biocompatibility, bioactive potential, porosity, and dentin/material interface of Bio-C Repair (BIOC-R), MTA Repair HP (MTAHP), and Intermediate Restorative Material (IRM). Materials and methods: Dentin tubes were implanted into subcutaneous of rats for 7, 15, 30, and 60 days. Thickness of capsules, number of inflammatory cells (ICs), interleukin-6 (IL-6), osteocalcin (OCN), and von Kossa were evaluated. Porosity and material/dentin interface voids were also analyzed. Data were submitted to ANOVA and Tukey's tests (p < 0.05). Results: IRM capsules were thicker and contained greater ICs and IL-6-immunopositive cells at 7 and 15 days. BIOC-R capsules exhibited higher thickness and ICs at 7 days and greater IL-6 at 7 and 15 days than MTAHP (p < 0.05). At 30 and 60 days, no significant difference was observed among the groups. OCN-immunopositive cells, von Kossa-positive, and birefringent structures were observed in BIOC-R and MTAHP. MTAHP exhibited higher porosity and interface voids (p < 0.05). Conclusions: BIOC-R, MTAHP, and IRM are biocompatible. Bioceramics materials demonstrate bioactive potential. MTAHP presented the highest porosity and presence of voids. Clinical relevance: BIOC-R and MTAHP have adequate biological properties. BIOC-R demonstrated lower porosity and presence of voids, which may represent better sealing for its clinical applications. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the physicochemical properties and biocompatibility of various calcium silicate–based bioceramic sealers (CSBSs). Four recently developed CSBSs, including AH Plus Bioceramic Sealer (AHB), EndoSequence BC Sealer (ESB), TotalFill BC Sealer (TTB), and Bio-C Sealer (BIC), were compared with the epoxy resin–based sealer AH Plus (AHP). Their physical properties, including flow, setting time, radiopacity, dimensional stability, and pH, were evaluated according to the International Organization for Standardization (ISO) 6876. Their cytotoxicity in human periodontal ligament fibroblast (hPDLF) was assessed through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and compared. Additionally, cell attachment to the sealer surface was analyzed using green fluorescent protein and confocal laser scanning microscopy to evaluate cell viability. Data were analyzed using a one-way analysis of variance to determine the difference between groups for categorical variables, followed by Tukey's post hoc test at the significance level of 95%. The flow, setting time, and radiopacity of all tested CSBSs satisfied the ISO 6876/2012 standards. Further, these CSBSs showed shrinkage after immersion in distilled water for 30 days and complied with the ISO 6876/2001 requirements. The pH values of AHB, ESB, TTB, and BIC were greater than 11, whereas AHP had a pH of 6.69 after 4 weeks. CSBS showed excellent biocompatibility compared with that of AHP (P <.05). Confocal laser scanning microscopy showed that alive hPDLFs were attached well to all the tested CSBSs but not to AHP. CSBSs have similar physical characteristics within the ISO standards and higher biocompatibility than epoxy resin–based sealers. [ABSTRACT FROM AUTHOR]

Recently introduced calcium silicate-based bioceramic (CSBC) sealers require moisture for setting, thus this study aimed to compare the setting times of epoxy resin-and CSBC sealers under different test conditions. Four CSBC sealers (CeraSeal, EndoSeal TCS, One-Fil, and Well-Root ST) were compared to an epoxy resin-based sealer (AH Plus). Each sealer was placed in a stainless-steel and gypsum molds on a glass slide. Sealer samples (n = 10 per group) were stored in an incubator at 95% humidity and 37 °C. A Gilmore needle with a total weight of 100 g and a 2.0-mm diameter were carefully placed vertically against the sealer, and the setting time was recorded when the needle no longer formed an indentation on the sealer surface. Statistical analysis was performed using two-way analysis of variance and Tukey parametric tests. The level of significance was set at 95%. The setting time of all sealers in gypsum molds was significantly shorter than that in stainless-steel molds (P < 0.05). While AH Plus showed the longest setting time, EndoSeal TCS, One-Fil, and CeraSeal showed the shortest setting times when using gypsum molds among the five sealer types (P < 0.05). The results of this study indicate that CSBC sealers require moisture for setting; a lack of moisture results in a significant delay in setting time. Because the root canals contain moisture, it is necessary to experiment with the setting time of all types of sealers using gypsum molds to determine the biological condition of root canals. [ABSTRACT FROM AUTHOR]

Bioceramics are very popular materials for tissue engineering applications due to their properties such as suitable bioactivity, biocompatibility, excellent compressive strength, and wear resistance. One of the most widely used bioceramics is calcium silicates. Calcium silicates are biocompatible and bioactive with relatively good mechanical properties, but high degradation rate. Elements such as magnesium (Mg), zirconium (Zr), and zinc (Zn) are added to calcium silicates to resolve this problem. Baghdadite (Ca3ZrSi2O9) with good biological properties is one of the calcium silicate based ceramics in which the zirconium element has replaced part of the calcium element. Also, the presence of calcium and zirconium elements has increased the biological and mechanical properties of this material. The purpose of this research was to synthesize Baghdadite powder using the sol-gel process and to characterize it using X-ray diffraction test to study the formed phases, halo test for antibacterial properties investigations, Fourier transform infrared spectroscopy to determine the functional groups, and field emission scanning electron microscope to examine the morphology of the powder. The results showed that the single-phase Baghdadite phase was formed with the particle size of 225 ± 15 nm and lumpy morphology. The elemental analysis test confirmed the presence of the main elements of Baghdadite (Ca, Si, Zr, and O) in the synthesized sample. Moreover, the elemental map analysis confirmed the uniformity of Baghdadite constituent elements. The results of the Disk diffusion test revealed that Baghdadite had no appropriate antibacterial properties against staphylococcus bacteria, but showed a slight antibacterial properties against Escherichia coli bacteria. [ABSTRACT FROM AUTHOR]

The development of a collagen-based composite scaffold to repair damaged bone is one of many important issues in tissue engineering. In this study, pure collagen, collagen/β-tricalcium phosphate (β-TCP), collagen/calcium silicate (CS), and collagen/β-TCP/CS scaffolds were fabricated using the freeze-drying method. The phase compositions, microstructures, and mechanical properties were characterized using X-ray diffraction, scanning electron microscopy, and a universal testing machine, respectively. In addition, cell viability was evaluated using an MTT assay. Finally, the correlations between the density, mechanical properties, and biodegradation behaviors of pore size distributions were discussed.

Introduction: Endodontic root canal sealers serve the purpose of providing a fluid-tight seal, sealing off accessory canals and multiple foramina, while comprehensively confining the bacteria. Of late, rather than seeking a hermetic seal of the root canal, a more biological perspective is being tackled in which, sealers resolve to interact with root dentin, resulting in bioactivity. Tricalcium silicate sealers set the bioactivity in motion on the material surface after contacting the tissue fluids. The Aim: The purpose of this paper is to review the properties of calcium silicate sealers in addition to the recent advances of the same and their clinical applications. Results: Although calcium silicate sealers possess subpar physical properties in comparison to resin-based sealers, they manifest promising properties like biocompatibility, antimicrobial potential along with their propensity for bioactivity. Conclusion: Beneficial properties of calcium silicate sealers render these sealers beneficial in the long-term success of root canal treatment. With newer competent sealers being put forth in the market on a regular basis, it is imperative to study their properties to simplify the clinician's selection of sealer, where indicated.

Introduction In addition to good biological properties, biomaterials should also possess appropriate physical properties in order to provide stability and longevity at the place of application. The aim of this work was to evaluate physical properties of an experimental nanostructured material based on calcium aluminate (CAL) and calcium silicate (CS). Material and method The research used nanostructured calcium aluminate synthesized by the hydrothermal solgel method from the individual components of calcium aluminate (CaO·Al2 O3 ), calcite (CaCO3 ) and barium sulfate (BaSO4 ) as an X-ray contrast agent and calcium silicate (CS). The prepared material was placed in plastic molds with a diameter of 5 ± 0.1 mm and a height of 2 ± 0.1 mm. After setting time, the materials were left in an incubator at 37°C for 24 hours, and then they were removed from the mold and absorption and solubility of the materials was calculated. MTA (Angelus Londrina, Brazil) was used as a control material. Results The lowest material solubility was recorded with MTA (0.255 mg/mm3 ), followed by calcium silicate (0.267 mg/mm3 ), and the highest with calcium aluminate (0.725 mg/mm3 ). The difference was statistically significant between calcium aluminate and MTA (p = 0.001901) and between calcium aluminate and calcium silicate (p = 0.002550). After 28 days in deionized water, the lowest water sorption was recorded with MTA (0.347 mg/mm3 ), followed by calcium silicate (0.357 mg/mm3 ), and the highest water sorption was measured with calcium aluminate (0.474 mg/mm3 ). Statistically significant differences were observed between calcium aluminate and MTA (p = 0.000283) and between calcium aluminate and calcium silicate (p = 0.001576). Conclusion Material solubility and water absorption of calcium aluminate-based nanostructured material was significantly higher compared to calcium silicate (CS) and MTA.

Amaç: Bu in vitro çalışmanın amacı, kan kontaminasyonunun farklı kök ucu dolgu materyallerinin dentine bağlanma dayanımına etkisinin değerlendirilmesiydi. Gereç ve Yöntem: Bu çalışmada tek köklü 90 adet maksiler santral diş kullanıldı. Dişlere endodontik tedavi uygulandıktan sonra kök uçları rezeke edildi ve kök ucu kaviteleri hazırlandı. Öncelikle örnekler, kavitelerin kanla kontaminasyonuna göre (+/-) 2 gruba ayrıldı. Daha sonra kök ucu dolgu malzemelerine göre üç alt gruba ayrıldı: MTA Repair HP, RetroMTA, MTA Flow (n=15). Bu malzemeler üreticinin talimatları doğrultusunda kaviteye yerleştirildi. Örnekler 21 gün boyunca 37 °C’de %100 nemli ortamda bekletildi. 1.0±0.1 mm kesitler elde edildikten sonra itme-bağlanma dayanımı testi gerçekleştirildi. Başarısızlık tipini değerlendirmek için her kesit stereomikroskop altında incelendi. Veriler tek yönlü varyans analizi ve bağımsız örneklem t-testi kullanılarak analiz edildi. Bulgular: Bağlanma dayanımı, kan kontaminasyonunun varlığından önemli ölçüde olumsuz yönde etkilendi (p0.05). Sonuç: Kan kontaminasyonu dentine bağlanma dayanımını azalttı. Materyaller arasında en yüksek bağlanma dayanımını MTA Flow gösterdi.

Hydraulic calcium silicate-based (HCS) sealers have recently gained tremendous popularity due to their unique properties. However, their removal during endodontic retreatment is challenging. The solvent, which could chemically deteriorate the material, would be highly desirable for endodontic retreatment procedures. This preliminary study assessed the interplay and dissolving capability of 10% and 20% citric acid, compared to 17% EDTA, on commonly used HCS sealers (AH Plus Bioceramic Sealer, Bio-C Sealer, BioRoot RCS, TotalFill BC Sealer), and evaluated the potential impact of these solutions on root dentin structure. The interaction between tested sealers and irrigating solutions was photographed, and solubility-related mass changes were determined. The surface morphology of treated filling materials and dentin was evaluated using a scanning electron microscope (SEM). One-way analysis of variance (ANOVA) along with Tukey’s test were used to detect the statistically significant differences among groups at the confidence level of 0.95. Intense gas release was observed during the interaction of HCS materials and citric acid, with no evidently visible “bubbling” after the immersion in EDTA. The mass loss of HCS sealers equally confirmed the significantly higher dissolving characteristics of 10% and 20% citric acid solutions compared to EDTA. The surface structural changes, associated with pore and crack formation, were mainly seen for HCS sealers exposed to citric acid. Meanwhile, no severe erosion was detected for dentin after root canal preparation with 10% and 20% citric acid solutions. These findings demonstrate that citric acid has the potential to dissolve HCS sealers with minimal or no negative impact on root dentin, suggesting citric acid as a solvent for HCS sealers in endodontic retreatment procedures.

The present in vitro study focuses on the filling ability of three different bioceramic cements with or without the addition of a bioceramic sealer in an open apex model on the marginal apical adaptation, tubule infiltrations, and void distributions as well as the interface between the cement and the sealer materials. To this end, sixty mandibular premolars were used. MTA-Biorep (BR), Biodentine (BD), and Well-Root Putty (WR) were used to obturate the open apex model with or without the addition of a bioceramic sealer, namely TotalFill® BC sealer™ (TF). A digital optical microscope and scanning electron microscope (SEM) were used to investigate the cement–dentin interface, marginal apical adaptation, and the material infiltration into the dentinal tubules. Micro-computed X-ray tomography and digital optical microscopy were used to investigate the cement–sealer interface. The results were analyzed by using the Kruskal–Wallis test. No significant difference was found between the groups for the marginal apical adaptation quality (p > 0.05). Good adaptation of the dentin–cement interface was found for all tested groups and the sealer was placed between the cement material and dentinal walls. All the groups demonstrated some infiltrations into the dentinal tubules at the coronal part except for the BR group. A good internal interface was found between the cement and the sealer with the presence of voids at the external interface. A larger number of voids were found in the case of the BD-TF group compared to each of the other two groups (p < 0.05). Within the limitations of the present in vitro study, all the groups demonstrated good marginal apical adaptation. The use of a sealer in an open apex does not guarantee good filling and, in addition, creates voids at the external interfaces with the dental walls when the premixed sealer is used with powder–liquid cement systems. The use of a premixed bioceramic cement could offer fewer complications than when a powder–liquid cement system is used.

Desired orthopedic implant materials must have a good biological activity and possess appropriate mechanical property that correspond to those of human bone. Although polyetheretherketone (PEEK) has displayed a promising application prospect in musculoskeletal and dentistry reconstruction thanks to its non-biodegradability and good biocompatibility in the body, the poor osseointegration and insufficient mechanical strength have significantly limited its application in the repair of load-bearing bones and surgical operations. In this study, carbon nanotubes (CNT)/calcium silicate (CS)/polyetheretherketone ternary composites were fabricated for the first time. The addition of CS was mainly aimed at improving biological activities and surface hydrophilicity, but it inevitably compromised the mechanical strength of PEEK. CNT can reinforce the composites even when brittle CS was introduced and further upgraded the biocompatibility of PEEK. The CNT/CS/PEEK composites exhibited higher mechanical strengths in tensile and bending tests, 64% and 90% higher than those of brittle CS/PEEK binary composites. Besides, after incorporation of CNT and CS into PEEK, the hydrophilicity, surface roughness and ability to induce apatite-layer deposition were significantly enhanced. More importantly, the adhesion, proliferation, and osteogenic differentiation of mouse embryo osteoblasts were effectively promoted on CNT/CS/PEEK composites. In contrast to PEEK, these composites exhibited a more satisfactory biocompatibility and osteoinductive activity. Overall, these results demonstrate that ternary CNT/CS/PEEK composites have the potential to serve as a feasible substitute to conventional metal alloys in musculoskeletal regeneration and orthopedic implantation.

The goal of biomaterial interest is the ease of the bone tissue regeneration process or the replacement of damaged bone and other tissues with recently generated bone tissue. Calcium silicate (CaSi) bioceramic is a vital material for bone tissue engineering, predominantly for bone repair. Though, the low toughness of calcium silicate imitates its load-bearing applications. The electrophoretic deposition technique was used to coat various concentrations of Zn2+ substituted CaSi on TNT. In this work, a novel as-obtained an appropriate orthopedic implant hybrid material by charged calcium ions of mineralized calcium silicate united with PCL-negatively charged graphene oxide [Zn-CaSi (S 1 -S 3)/PCL (P 1 -P 3)/GO]. Hence, the effectively as-obtained [Zn-CaSi (S 1 -S 3)/PCL (P 1 -P 3)/GO] bone-like apatite on the ternary composite coatings on the surface was proven via XRD, FT-IR, FESEM with EDAX spectra, HR-TEM and BET analyses etc., Moreover, the TNT/S 2 /P 2 @GO ternary composite coatings exhibit better mechanical properties and antibacterial activity. The metal ions released from the coatings were calculated via ICP-AES studies. Moreover, the cell viability and also the live/dead staining of MG63 human osteoblasts cells on the subsequent composite coating material for better cell growth in orthopedic applications. [ABSTRACT FROM AUTHOR]

The paper shows a new technological approach to the processing of phosphorus-containing raw materials using Syrian phosphorite as an example. Thermodynamic calculations of possible processes of interaction of apatites with KOH and quartz are made, assumptions about the interaction are experimentally verified, and the resulting substances are determined by X-ray phase analysis. The results obtained allow us to recommend the method of sintering followed by leaching with water as a promising technology for the production of fertilizers from phosphorus-containing raw materials, bypassing the stage of production of extractive phosphoric acid. [ABSTRACT FROM AUTHOR]

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Calcium silicate‐based materials are hydrophilic materials with biocompatibility and bioactivity properties. Despite many advantages, they might present some problems related to discolouration, setting time, manipulation and solubility depending on the composition of the product and the type of clinical application. Calcium silicate‐based materials can be evaluated under two types according to their intended use: calcium silicate‐based cements (CSCs) and calcium silicate‐based sealers (CSSs). CSCs can be used in many endodontic procedures including perforation repair, resorption repair, apical barriers, guided endodontic repair, vital pulp treatment, endodontic surgery, root fractures and root canal filling as a core obturation material. CSSs are available for use with gutta‐percha to obturate root canals using cold and warm techniques, including the sealer‐based obturation technique. The purpose of this review is to evaluate the available literature on CSCs and CSSs and to provide up‐to‐date information and recommendations for their clinical applications. [ABSTRACT FROM AUTHOR]

Synthetic calcium silicates and phosphates are promising compounds for targeted drug delivery for the effective treatment of cancerous tumors, and for minimizing toxic effects on the patient's entire body. This work presents an original synthesis of a composite based on crystalline wollastonite CaSiO3 and combeite Na4Ca4(Si6O18), using a sea urchin Mesocentrotus nudus skeleton by microwave heating under hydrothermal conditions. The phase and elemental composition and structure of the obtained composite were studied by XRF, REM, BET, and EDS methods, depending on the microwave heating time of 30 or 60 min, respectively, and the influence of thermo-oxidative post-treatment of samples. The role of the sea urchin skeleton in the synthesis was shown. First, it provides a raw material base (source of Ca2+) for the formation of the calcium silicate composite. Second, it is a matrix for the formation of its porous inorganic framework. The sorption capacity of the composite, with respect to 5-fluorouracil, was estimated, the value of which was 12.3 mg/L. The resulting composite is a promising carrier for the targeted delivery of chemotherapeutic drugs. The mechanism of drug release from an inorganic natural matrix was also evaluated by fitting its release profile to various mathematical models. [ABSTRACT FROM AUTHOR]

The bone, being an essential tissue in the human body, not only protects the organs inside the body but also provides mechanical support, haematopoiesis, mineral storage and mobility. Although bone may regenerate and heal itself, significant bone defects caused by severe trauma, tumour removal, malignancy, or congenital diseases can only be corrected via bone grafting. Bone biomaterials, also known as bone graft alternatives, have seen an increase in demand in recent years. Over 2 million procedures are performed in the United States each year to restore damaged/fractured bones by grafting. The number of patients in China with reduced limb function owing to bone abnormalities has risen to 10 million. Traditional bone defect repair materials include autogenous bone, allogeneic bone, xenogeneic bone, decalcified bone matrix, bioceramics, and metal materials, which are easily available and processed. Calcium silicate (Ca-Si) ceramic is among the most promising bioceramics for these purposes due to their amazing characteristics such as bioactivity, biocompatibility and osteoinductivity. Unfortunately, its high biodegradation rate along with its poor strength represents major limitations that limit its use in clinical applications significantly. In light of the above, this article briefly discussed the different types of bone substitute materials, the properties of Ca-Si ceramic, the advantages, limitations and potential solutions to overcome these drawbacks and its biomedical applications such as orthopedic, dental, wound healing and drug delivery. [ABSTRACT FROM AUTHOR]