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1.
Braz. j. oral sci ; 20: e214073, jan.-dez. 2021. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1282556

RESUMO

Aim: this study aimed to compare the sealing ability of two types of commercially available calcium silicate bioceramic based root canal sealers and a resin based root canal sealer. Methods: Twenty one single-rooted teeth were used, samples (n= 21) were randomly divided into three groups according to the sealer used (group A; ADSEAL, group B; Wellroot, group C; Ceraseal). Roots were then cleaved longitudinally in the labiolingual direction; all samples were then sectioned at three, six, and nine mm from the root tip. The penetration of sealers into the dentinal tubules was examined at 1000x with a scanning electron microscope. Data were tested for normality using Shapiro Wilk test. ANOVA test was used for analyzing normally distributed data followed by Bonferroni post hoc test for pair-wise comparison. Significance level p≤0.001. Results: groups B and C showed better sealing ability than group A in all the three sections. The coronal section showed higher sealing ability than the middle section followed by the apical section in the three tested groups. Conclusion: it can be concluded that both calcium silicate-based sealers had better sealing ability and higher bond strength than the resin epoxy- based sealer


Assuntos
Materiais Restauradores do Canal Radicular , Silicatos , Compostos de Cálcio , Resinas Epóxi , Tomografia com Microscopia Eletrônica
2.
J Appl Oral Sci ; 29: e20210081, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34614120

RESUMO

OBJECTIVE: To evaluate the effect of a toothpaste containing calcium silicate/sodium phosphate/fluoride associated or not to the boost serum (BS) against erosive tooth wear (ETW) on enamel and dentin. METHODOLOGY: Bovine enamel and dentin specimens were subjected to an erosion-abrasion cycling model (1% citric acid - pH 3.6 -2 min / artificial saliva - 60 min, 4×/day, 5 days). Toothbrushing was performed for 15 s (2 min exposed to slurry), 2×/day, with the toothpastes (n=10): control without fluoride (Weleda), Arg/Ca/MFP (Colgate Pro-Relief), Si/PO4/MFP (Regenerate-Unilever), and Si/PO4/MFP/BS (Si/PO4/MFP with dual BS - Advanced Enamel Serum-Unilever). The effect of treatments on the eroded tissues was assessed by surface microhardness in the first day, and surface loss (SL) resulting from ETW was evaluated by profilometry (µm) after three and five days. Additional dentin specimens (n=5/group) were subjected to 20,000 brushing cycles to verify the abrasivity of the toothpastes. Data were subjected to ANOVA and correlation tests (5%). RESULTS: For enamel, no difference in microhardness was observed among the treated groups, and similar SL was obtained after 5 days. For dentin, Si/PO4/MFP/BS resulted in higher microhardness values, but none of the groups presented significantly lower SL than the control. There was no significant correlation between SL and abrasiveness. CONCLUSION: The calcium silicate/sodium phosphate toothpaste and serum increased microhardness of eroded dentin, but they did not significantly reduce enamel and dentin loss compared to the non-fluoride control toothpaste. The abrasiveness of the toothpastes could not predict their effect on ETW.


Assuntos
Fluoretos , Cremes Dentais , Animais , Compostos de Cálcio , Bovinos , Esmalte Dentário , Dentina , Fosfatos , Silicatos
3.
Biomed Res Int ; 2021: 7343147, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34540997

RESUMO

This study was aimed at fabricating and evaluating the physical and bioproperties of nanofast cement (NFC) as a replacement of the MTA. The cement particles were decreased in nanoscale, and zirconium oxide was used as a radiopacifier. The setting time and radiopacity were investigated according to ISO recommendations. Analysis of color, bioactivity, and cytotoxicity was performed using spectroscopy, simulated body fluid (SBF), and MTT assay. The setting time of cement pastes significantly dropped from 65 to 15 min when the particle sizes decreased from 2723 nm to 322 nm. Nanoparticles provide large surface areas and nucleation sites and thereby a higher hydration rate, so they reduced the setting time. Based on the resulting spectroscopy, the specimens did not exhibit clinically noticeable discoloration. Resistance to discoloration may be due to the resistance of zirconium oxide to decomposition. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and infrared spectroscopy (FTIR) examinations of the immersed SBF samples showed apatite formation that was a reason for its suitable bioactivity. The results of cell culture revealed that NFC is nontoxic. This study showed that NFC was more beneficial than MTA in dental restorations.


Assuntos
Cimentos Dentários/química , Restauração Dentária Permanente/métodos , Nanoestruturas/química , Bismuto/química , Cimentos Ósseos/análise , Cimentos Ósseos/química , Compostos de Cálcio/química , Hidróxido de Cálcio/química , Cimentos Dentários/análise , Cimentos de Ionômeros de Vidro/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Óxidos/química , Materiais Restauradores do Canal Radicular/química , Silicatos/química , Propriedades de Superfície , Água/química , Difração de Raios X , Zircônio/química
4.
Anal Chem ; 93(33): 11557-11567, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34370456

RESUMO

This paper examines the production technology of Egyptian blue, an ancient artificial pigment, through the investigation of an unsuccessfully produced pellet derived from the Hellenistic production site of Kos (Dodecanese, Greece). This heterogeneous material was investigated by a combination of laboratory and synchrotron radiation-based (SR) techniques: scanning electron microscopy coupled with energy-dispersive X-ray spectrometry, micro-Raman spectroscopy, high-resolution SR micro-X-ray fluorescence spectroscopy, and SR micro-X-ray absorption near-edge structure spectroscopy (XANES), at the ID21 beamline of the European Synchrotron Radiation Facility. Principal component analysis of a large dataset of 171 micro-XANES spectra acquired on the archaeological samples and on a series of reference copper compounds emphasizes high variations of XANES features due to different speciation and also orientation effects, as demonstrated by the simulated XANES spectra. The results indicate that, rather than inadequate firing temperatures that could have led to the reddish cuprite (Cu2O), unsuccessful production may occur due to the use of inappropriate starting materials, which contain an unusually high iron content. The contextual interpretation underlines the intertwined relationship between the production of Egyptian blue and metallurgy.


Assuntos
Cobre , Síncrotrons , Cobre/análise , Grécia , Silicatos , Espectroscopia por Absorção de Raios X
5.
BMC Musculoskelet Disord ; 22(1): 673, 2021 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-34372804

RESUMO

BACKGROUND: ß-Tricalcium phosphate (ß-TCP) is a popular synthetic bone graft substitute with excellent osteoconductive properties and bioabsorbability. However, its osteoinductive properties are inferior to those of autologous or allogeneic bone. Trace elements such as strontium (Sr), silica (Si), and zinc (Zn) have been reported to promote osteogenesis in materials. In this study, we aimed to determine whether a Si/Zn-substituted Sr apatite coating of ß-TCP could enhance osteoinductive properties. METHODS: The apatite-coated ß-TCP disks were prepared using nanoparticle suspensions of silicate-substituted Sr apatite (SrSiP) or silicate- and Zn-co-substituted Sr apatite (SrZnSiP). Bone marrow mesenchymal cells (BMSCs) from rat femur were cultured and subsequently seeded at a density of 1.0 × 106/cm2 onto apatite-coated and non-coated ß-TCP disks. In vitro, the ß-TCP disks were then placed in osteogenic medium, and lactate dehydrogenase (LDH) activity was measured from supernatants after culture for 2 days. Additionally, after culture for 14 days, the mRNA expression of genes encoding osteocalcin (OC), alkaline phosphatase (ALP), bone morphogenetic protein-2 (BMP-2), and vascular endothelial growth factor (VEGF) was evaluated by qRT-PCR. In vivo, the ß-TCP disks were transplanted subcutaneously into rats that were sacrificed after 4 weeks. Then, the harvested disks were evaluated biochemically (ALP activity, OC content, mRNA expression of OC, ALP, BMP-2, and VEGF measured by qRT-PCR), radiologically, and histologically. RESULTS: Significantly higher mRNA expression of almost all evaluated osteogenic and angiogenic genes was observed in the SrZnSiP and SrSiP groups than in the non-coated group, with no significant cytotoxicity elicited by the apatite coating in vitro. Moreover, in vivo, the SrZnSiP and SrSiP groups showed significantly higher osteogenic and angiogenic gene expression and higher ALP activity and OC content than the non-coated group (P < 0.05). Radiological and histopathological findings revealed abundant bone formation in the apatite-coated group. CONCLUSIONS: Our findings indicate that apatite coating of ß-TCP improves osteoinductive properties without inducing significant cytotoxicity.


Assuntos
Apatitas , Substitutos Ósseos , Animais , Fosfatos de Cálcio , Células Cultivadas , Osteogênese , Ratos , Silicatos/farmacologia , Estrôncio , Fator A de Crescimento do Endotélio Vascular , Zinco/farmacologia
6.
ACS Biomater Sci Eng ; 7(9): 4483-4493, 2021 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-34382772

RESUMO

The traditional silicate bioactive glasses exhibit poor thermal processability, which inhibits fiber drawing or sintering into scaffolds. The composition of the silicate glasses has been modified to enable hot processing. However, the hot forming ability is generally at the expense of bioactivity. Metaphosphate glasses, on the other hand, possess excellent thermal processability, congruent dissolution, and a tailorable degradation rate. However, due to the layer-by-layer dissolution mechanism, cells do not attach to the material surface. Furthermore, the congruent dissolution leads to a low density of OH groups forming on the glass surface, limiting the adsorption of proteins. It is well regarded that the initial step of protein adsorption is critical as the cells interact with this protein layer, rather than the biomaterial itself. In this paper, we explore the possibility of improving protein adsorption on the surface of phosphate glasses through a variety of surface treatments, such as washing the glass surface in acidic (pH 5), neutral, and basic (pH 9) buffer solutions followed or not by a treatment with (3-aminopropyl)triethoxysilane (APTS). The impact of these surface treatments on the surface chemistry (contact angle, ζ-potential) and glass structure (FTIR) was assessed. In this manuscript, we demonstrate that understanding of the material surface chemistry enables to selectively improve the adsorption of albumin and fibronectin (used as model proteins). Furthermore, in this study, well-known silicate bioactive glasses (i.e., S53P4 and 13-93) were used as controls. While surface treatments clearly improved proteins adsorption on the surface of both silicate and phosphate glasses, it is of interest to note that protein adsorption on phosphate glasses was drastically improved to reach similar protein grafting ability to the silicate bioactive glasses. Overall, this study demonstrates that the limited cell/phosphate glass biological response can easily be overcome through deep understanding and control of the glass surface chemistry.


Assuntos
Implantes Absorvíveis , Fosfatos , Adsorção , Vidro , Silicatos
7.
Int J Mol Sci ; 22(16)2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34445403

RESUMO

Natural smectites have demonstrated efficacy in the treatment of diarrhea. The present study evaluated the prophylactic effect of a diosmectite (FI5pp) on the clinical course, colon damage, expression of tight junction (TJ) proteins and the composition of the gut microbiota in dextran sulfate sodium (DSS) colitis. Diosmectite was administered daily to Balb/c mice from day 1 to 7 by oral gavage, followed by induction of acute DSS-colitis from day 8 to 14 ("Control", n = 6; "DSS", n = 10; "FI5pp + DSS", n = 11). Mice were sacrificed on day 21. Clinical symptoms (body weight, stool consistency and occult blood) were checked daily after colitis induction. Colon tissue was collected for histological damage scoring and quantification of tight junction protein expression. Stool samples were collected for microbiome analysis. Our study revealed prophylactic diosmectite treatment attenuated the severity of DSS colitis, which was apparent by significantly reduced weight loss (p = 0.022 vs. DSS), disease activity index (p = 0.0025 vs. DSS) and histological damage score (p = 0.023 vs. DSS). No significant effects were obtained for the expression of TJ proteins (claudin-2 and claudin-3) after diosmectite treatment. Characterization of the microbial composition by 16S amplicon NGS showed that diosmectite treatment modified the DSS-associated dysbiosis. Thus, diosmectites are promising candidates for therapeutic approaches to target intestinal inflammation and to identify possible underlying mechanisms of diosmectites in further studies.


Assuntos
Bactérias/classificação , Colite/tratamento farmacológico , Sulfato de Dextrana/efeitos adversos , Microbiota/efeitos dos fármacos , Silicatos/administração & dosagem , Administração Oral , Animais , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Peso Corporal/efeitos dos fármacos , Colite/induzido quimicamente , Colite/metabolismo , Colite/microbiologia , DNA Bacteriano/genética , DNA Ribossômico/genética , Fezes/microbiologia , Masculino , Camundongos Endogâmicos BALB C , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Índice de Gravidade de Doença , Silicatos/farmacologia , Proteínas de Junções Íntimas/metabolismo , Resultado do Tratamento
8.
Bioresour Technol ; 340: 125678, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34339995

RESUMO

The phosphorous supply crisis is a major challenge for a sustainable society, and the algal industry is not unrelated to this crisis. Recycling phosphorus from sewage wastewater is a potential way to address this issue. We previously developed amorphous calcium silicate hydrates (aCSH) as excellent phosphorus recovery materials. In this study, we designed a phosphorus recovery process using aCSH in a pilot-scale facility connected to a sewage wastewater treatment plant, and demonstrated the production of microalgal biomass using phosphorous-containing aCSH (P_aCSH). As a result, high phosphorous recovery rates (>80%) were obtained throughout the year. The carbohydrate-rich microalga Pseudoneochloris sp. NKY372003 was cultivable with P_aCSH. The biomass and carbohydrate productivity of this microalga with P_aCSH was comparable to that with conventional media. Approximately 94% of the phosphorus in P_aCSH was recycled into the biomass. This study successfully demonstrated the recycling the phosphorus recovered from wastewater for microalgal cultivation by aCSH.


Assuntos
Fósforo , Águas Residuárias , Biomassa , Compostos de Cálcio , Silicatos
9.
Braz Oral Res ; 35: e086, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34378668

RESUMO

This study evaluated the cytotoxicity, the antimicrobial and physicochemical properties of root canal sealers incorporated with phytotherapic Uncaria tomentosa (UT). Unmodified AH Plus (Dentsply, DeTrey, Germany) and MTA Fillapex (Angelus, Londrina, Brazil) were used as controls. UT was incorporated into AH Plus and MTA Fillapex, at concentrations of 2% and 5% of the total weight of these sealers (w/w). Flowability, setting time, and solubility were evaluated following ISO requirements. The pH values were measured at periods of 12, 24, 48 hours, and 7 days. The antimicrobial activity of the sealers against Enterococcus faecalis was analyzed by both direct contact tests in freshly prepared sealers, and after 7 days. The cytotoxicity of the samples was evaluated by the MTT assay, to check Balb/c 3T3 cell viability. The statistical analysis was performed by one-way ANOVA and Tukey's test (p < 0.05). The incorporation of UT was associated with a decrease in flow, for both sealers, an increase in AH Plus setting time, increase in MTA Fillapex pH values, and solubility (after 14 days), for both sealers (p < 0.05). Regarding the antibacterial evaluation, bacterial reduction was reported after incorporation of UT into both AH Plus and MTA Fillapex, up to 7 days after handling of the material (P<0.05). UT incorporation decreased the cytotoxic effects of both AH Plus and MTA Fillapex sealers in a way directly proportional to their respective concentrations (p < 0.05). In conclusion, UT can be added to both sealers to reduce their cytotoxicity, and improve their antibacterial effects, without compromising their original physicochemical properties.


Assuntos
Unha-de-Gato , Materiais Restauradores do Canal Radicular , Antibacterianos/toxicidade , Compostos de Cálcio , Combinação de Medicamentos , Resinas Epóxi/toxicidade , Humanos , Teste de Materiais , Óxidos , Materiais Restauradores do Canal Radicular/toxicidade , Silicatos
10.
An Acad Bras Cienc ; 93(4): e20200002, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34378758

RESUMO

In the current study, twenty-eight bacterial strains were isolated from home-made yogurt samples from Agri Province, Turkey. The bacterial strains were identified by conventional and molecular techniques. Among the twenty- eight isolates, seventeen isolates were identified according to the 16 S rDNA region and determined to belong to five different genus including Sphingomonas (8 isolates), Burkholderia (5 isolates), Lactobacillus (2 isolates), Lactococcus (1 isolate), Staphylococcus (1 isolate). In this study, the presence of Burkholderia in home-made yogurt samples were reported for the first time, whereas Sphingomonas was detected for the second time. We also investigated the carbonate (CaCO3 and MgCO3) and silicate ( CaSiO3 and MgSiO3) dissolving potential of seventeen bacterial isolates. Among these seventeen bacterial isolates, fifteen bacterial isolates have CaCO3-dissolving and 10 bacterial isolates have MgCO3-dissolving potential. The silicates dissolution ability was relatively less than that of carbonates dissolving. We observed that six bacterial isolates have CaSiO3 and only two bacterial isolates have MgSiO3 dissolution abilities. In conclusion, this work clearly shows the diversity of bacteria existing in fermented cow milk samples in Agri Province, Turkey, which could be considered as valuable sources for lactic acid bacteria (LAB) isolation and further probiotic potential.


Assuntos
Probióticos , Iogurte , Animais , Carbonatos , Bovinos , Feminino , Lactobacillus , Silicatos
11.
J Contemp Dent Pract ; 22(6): 674-679, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34393126

RESUMO

AIM: The purpose of this in vitro study was to evaluate the intraorifice sealing ability of light-cured glass-ionomer cement (LC-GIC), Tetric N-Flow, and ProRoot mineral trioxide aggregate (MTA) against Enterococcus faecalis and Proteus vulgaris. MATERIALS AND METHODS: Crowns of the eighty human mandibular teeth were decapitated. Working length determination was performed, after which cleaning and shaping were carried out. A uniform orifice diameter of 1.3 mm, at its widest point, was made. Once instrumentation was completed, the canals were irrigated and then obturated. A heat carrier was used to remove gutta-percha to the depth of 3.5 mm. Samples were then divided into a control group (Group 1) with no barrier, and three groups, namely, Group 2, Group 3, and Group 4, were restored with the LC-GIC, Tetric N-Flow, and ProRoot MTA, respectively. The groups were further subdivided into Subgroup A for checking bacterial leakage against E. faecalis and Subgroup B, against P. vulgaris. All samples were subjected to the bacterial leakage test and observed daily for the appearance of turbidity after which statistical analysis was performed. RESULTS: Group 1 showed leakage in, as early as, 3 days. The longest time for the turbidity to appear was shown by Group 4 with an average of 31 days. The mean number of days for turbidity to appear in Group 2 and Group 3 was 23 and 24 days, respectively. Group 4 showed the best intraorifice sealing ability with a significant difference. CONCLUSION: The teeth with an intraorifice coronal seal had better protection against microbial leakage. Among all materials used, the ProRoot MTA showed the best intraorifice sealing ability. CLINICAL SIGNIFICANCE: Use of the ProRoot MTA promises long-term results in the endodontically treated teeth as compared with other materials.


Assuntos
Infiltração Dentária , Materiais Restauradores do Canal Radicular , Compostos de Alumínio , Compostos de Cálcio , Infiltração Dentária/prevenção & controle , Combinação de Medicamentos , Enterococcus faecalis , Guta-Percha , Humanos , Óxidos , Proteus vulgaris , Silicatos
12.
J Contemp Dent Pract ; 22(6): 680-685, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34393127

RESUMO

AIM: The aim of the study is (a) To use collagen as a pulpotomy material in comparison with the gold standard formocresol-based pulpotomy, (b) to assess the clinical and radiographic success rate of formocresol pulpotomy and collagen-based pulpotomy, and (c) to compare the success rate of formocresol-based pulpotomy and collagen-based pulpotomy over a definitive interval of time. MATERIALS AND METHODS: Totally 30 primary first or second molars indicated for pulpotomy after confirming with the operative diagnosis were taken as samples for this study. This split-mouth technique consists of two groups: Group 1-formocresol pulpotomy (n = 15), and group 2-collagen-based pulpotomy (n = 15). Both the procedures were done in the same patient on regular appointments. Pre- and postoperative radiographs were taken. The children were recalled for clinical and radiographic follow-up at 2, 4, and 6 months. The success of the procedure was assessed based on clinical signs (pain, tenderness to percussion, abscess, swelling, fistula, and pathologic mobility) and radiographic findings (radicular radiolucency, internal and external root resorption, periodontal ligament (PDL) space widening, and furcation radiolucency). The Chi-square test was used to compare the differences between the groups. RESULT: The overall success rate for formocresol pulpotomy (n = 15) was 14, 13, and 10 for the second-, fourth-, and sixth-month review period, respectively. For collagen pulpotomy group (n = 15), the overall success rate was 14, 14, and 14 for the second-, fourth-, and sixth-month review period, respectively. The obtained data from the overall success rate were subjected to statistical analysis, and chi-square test was used. The p-value less than 0.1 was considered a statistically significant result. The chi-square value for the fourth- and sixth-month review was 0.37 and 3.33, respectively. CONCLUSION: Statistically significant value was obtained from the sixth-month review period (p <0.1), which describes that the overall success rate was better for the collagen pulpotomy group when compared with the formocresol pulpotomy group. CLINICAL SIGNIFICANCE: Collagen had proven to be a very good alternative for formocresol, its biocompatibility, and regenerative efficiency and is a benchmark for a better clinical success rate in dentistry. However, its implication in pulpotomy should be subjected to further comparative research study on mineral trioxide aggregate (MTA), Biodentine, etc. Keywords: Collagen-based pulpotomy, Formocresol-based pulpotomy.


Assuntos
Formocresóis , Pulpotomia , Compostos de Alumínio , Compostos de Cálcio , Criança , Colágeno , Combinação de Medicamentos , Humanos , Dente Molar/diagnóstico por imagem , Dente Molar/cirurgia , Óxidos , Silicatos , Dente Decíduo
13.
Environ Sci Technol ; 55(17): 11906-11915, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34415763

RESUMO

The world adds about 51 Gt of greenhouse gases to the atmosphere each year, which will yield dire global consequences without aggressive action in the form of carbon dioxide removal (CDR) and other technologies. A suggested guideline requires that proposed CDR technologies be capable of removing at least 1% of current annual emissions, about half a gigaton, from the atmosphere each year once fully implemented for them to be worthy of pursuit. Basalt carbonation coupled to direct air capture (DAC) can exceed this baseline, but it is likely that implementation at the gigaton-per-year scale will require increasing per-well CO2 injection rates to a point where CO2 forms a persistent, free-phase CO2 plume in the basaltic subsurface. Here, we use a series of thermodynamic calculations and basalt dissolution simulations to show that the development of a persistent plume will reduce carbonation efficiency (i.e., the amount of CO2 mineralized per kilogram of basalt dissolved) relative to existing field projects and experimental studies. We show that variations in carbonation efficiency are directly related to carbonate mineral solubility, which is a function of solution alkalinity and pH/CO2 fugacity. The simulations demonstrate the sensitivity of carbonation efficiency to solution alkalinity and caution against directly extrapolating carbonation efficiencies inferred from laboratory studies and small-injection-rate field studies conducted under elevated alkalinity and/or pH conditions to gigaton-per-year scale basalt carbonation. Nevertheless, all simulations demonstrate significant carbonate mineralization and thus imply that significant mineral carbonation can be expected even at the gigaton-per-year scale if basalts are given time to react.


Assuntos
Dióxido de Carbono , Silicatos , Carbonatos , Minerais
14.
J Mech Behav Biomed Mater ; 123: 104785, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34416535

RESUMO

The purpose of this study was to improve interfacial interaction between basalt fibers (BF) and glass ionomer cement (GIC) matrix with grafting amine terminated urea-based oligomer (DIEDA) onto the surface of BF. The DIEDA-BF was prepared by the reaction between 3-aminopropyl- triethoxysilane (APS) modified BF with Isophorone diisocyanate (IPDI) and followed with ethylenediamine (EDA). The reaction was repeated to obtain three generations of DIEDA-BF which were marked as DIEDA-BF-G1, DIEDA-BF-G2, and DIEDA-BF-G3, respectively. X-ray photoelectron spectroscopy (XPS) was used to characterize DIEDA-BF. 3D morphology analysis was taken to investigate the variation of BF after being treated with EDA. Three-point bending-test, compressive strength (CS) test, and fracture toughness (FT) were used to evaluate the reinforcement effect of DIEDA-BF on commercial GIC (GC Fuji IX). Water sorption (WS) and solubility (SL) were measured according to the mass variation at fixed time intervals. The changes of flexural strength (FS) and modulus (FM) after water immersion were used to evaluate the water-aging resistance of DIEDA-BF reinforced GIC. Pure GIC and APS reinforced GIC (APS-GIC) were used as double control groups. The XPS analysis indicated that DIEDA was successfully grafted onto the surface of BF. 3D morphology analysis revealed that BF could be corroded in EDA, thus DIEDA-BF-G3 had lower N content on the surface than DIEDA-BF-G2. The results of mechanical tests showed that DIEDA-BF-G1 and DIEDA-BF-G2 had the best reinforcement effect. The DIEDA-BF-G1 reinforcement GIC (DIEDA-BF-G1-GIC) was chosen for WS, SL, and water aging resistance test further. The results showed that all fiber reinforced GICs had higher WS than pure GIC, and the relationship in SL between fiber reinforced GICs and pure GIC varied with immersion time. The FS of DIEDA-BF-G1-GIC decreased after one week of water immersion, and had no variation after prolonging the immersion time. After three months of water immersion, DIEDA-BF-G1-GIC still had much higher FS than pure GIC and APS-BF-GIC. DIEDA could improve the interfacial interaction between BF and GIC matrix. After long term of water immersion, DIEDA-BF reinforced GIC still had FS higher than 50 MPa, which even met the ISO requirement in FS for dental resin composite. Therefore, GIC/DIEDA modified BF composite had potential to be used in stress bearing areas in dentistry.


Assuntos
Aminas , Ureia , Cimentos de Ionômeros de Vidro , Teste de Materiais , Silicatos
15.
J Prosthet Dent ; 126(4): 588.e1-588.e5, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34340825

RESUMO

STATEMENT OF PROBLEM: Whether reusing the buttons of pressable ceramic materials affects their color or translucency is unclear. PURPOSE: The purpose of this in vitro study was to investigate the effect of additional pressing on the color and translucency of 3 different lithium disilicate ceramic brands. MATERIAL AND METHODS: Seventy-two disk-shaped ceramic specimens (Ø14×1.5 mm) were divided into 2 groups: pressed group and additionally pressed group, each containing 36 specimens. These groups were further divided into 3 subgroups: lithium disilicate (LDS), lithium disilicate with high-density micronization technology (LDS-HDM), and zirconia-reinforced lithium silicate (ZLS). Pressing was performed in the press group yielding 36 pressed specimens. Additional pressing was performed by using the buttons resulting from the press group, yielding 36 additionally pressed specimens. Color differences and translucency between pressed and additionally pressed groups were measured with a portable spectrophotometer (VITA Easyshade Compact). The translucency parameter (TP) was measured on black and white backgrounds. Color differences between the 2 groups were analyzed statistically by using the Kruskal-Wallis nonparametric test followed by the Dunn-Sidek method for individual comparison among means of all groups (α=.05). RESULTS: A statistically significant difference was found in color after additional pressing among the 3 tested materials (P=.005). After additional pressing, color difference (ΔE) values were found between the LDS group (3.78 ±1.11) and the ZLS group (3.03 ±1.44). These ΔE values were beyond the selected clinical perceptible threshold (ΔE=2.6). However, the LDS-HDM group had a ΔE value of 1.80 ±1.22, which is considered clinically not perceivable. Furthermore, LDS showed a statistically significant decrease in translucency after additional pressing (P=.002). However, after additional pressing, ZLS and LDS-HDM showed no statistically significant differences in translucency (P>.05). CONCLUSIONS: The colors of the 3 tested materials were affected by additional pressing. Only LDS-HDM showed color changes below the selected clinically perceptible threshold (ΔE=2.6). Furthermore, only LDS showed a significant decrease in translucency.


Assuntos
Cerâmica , Porcelana Dentária , Cor , Teste de Materiais , Silicatos , Propriedades de Superfície
16.
BMC Oral Health ; 21(1): 407, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34407774

RESUMO

BACKGROUND: Research shows that nano-bioceramics can modulate the differentiation of dental stem cells. The novel ready-to-use calcium-silicate-based root-canal sealer iRoot SP is widely used in root filling. Accordingly, the aim of this study was to evaluate the effects of iRoot SP on proliferation and osteogenic differentiation in human stem cells from the apical papilla (hSCAPs). METHODS: hSCAPs were isolated and characterized in vitro, then cultured with various concentrations of iRoot SP extract. Cell proliferation was assessed by CCK-8 assay, and scratch-wound-healing assays were performed to evaluate cell-migration capacity. hSCAPs were then cultured in osteogenic medium supplemented with iRoot SP extracts. Alkaline phosphatase (ALP) activity assay was used to evaluate ALP enzyme levels. Alizarin red staining and cetylpyridinium chloride (CPC) assays were performed to assess calcified-nodule formation and matrix-calcium accumulation of hSCAPs. The mRNA and protein expression levels of the osteogenic markers OCN, OSX, Runx2, and DSPP were determined by qRT-PCR and Western blotting. The data were analyzed using one-way ANOVA and LSD-t tests. RESULTS: iRoot SP at low concentrations (2, 0.2, and 0.02 mg/mL) is nontoxic to hSCAPs. iRoot SP at concentrations of 0.02 and 0.2 mg/mL significantly increases cell-migration capacity. In terms of osteogenic differentiation, 0.2 mg/mL iRoot SP promotes intracellular ALP activity and the formation of mineralized nodules. Moreover, the expression of osteogenic markers at the mRNA and protein levels are upregulated by iRoot SP. CONCLUSION: iRoot SP is an effective filling material for periapical bone regeneration.


Assuntos
Osteogênese , Silicatos , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Humanos , Materiais Restauradores do Canal Radicular , Silicatos/farmacologia , Células-Tronco
17.
Environ Sci Technol ; 55(18): 12362-12371, 2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34464125

RESUMO

Enhanced silicate weathering (ESW) by spreading finely ground silicate rock along the coastal zone to remove atmospheric carbon dioxide (CO2) is a proposed climate change mitigation technique. The abundant and fast-dissolving mineral olivine has received the most attention for this application. However, olivine contains nickel (Ni) and chromium (Cr), which may pose a risk to marine biota during a gigaton-scale ESW application. Herein we derive a first guideline for coastal olivine dispersal based on existing marine environmental quality standards (EQS) for Ni and Cr. Results show that benthic biota are at the highest risk when olivine and its associated trace metals are mixed in the surface sediment. Specifically, depending on local sedimentary Ni concentrations, 0.059-1.4 kg of olivine m-2 of seabed could be supplied without posing risks for benthic biota. Accordingly, globally coastal ESW could safely sequester only 0.51-37 Gt of CO2 in the 21st century. On the basis of current EQS, we conclude that adverse environmental impacts from Ni and Cr release could reduce the applicability of olivine in coastal ESW. Our findings call for more in-depth studies on the potential toxicity of olivine toward benthic marine biota, especially in regard to bioavailability and metal mixture toxicity.


Assuntos
Cromo , Níquel , Compostos de Ferro , Compostos de Magnésio , Silicatos
18.
Biomolecules ; 11(8)2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34439856

RESUMO

The effects of elicitors on broccoli (Brassica oleracea L. var. Italica) and radish (Raphanus sativus L.) sprouts were evaluated. Seeds and then sprouts were soaked daily for 30 min over 6 days in water (control) or a mixture of FeEDTA and sodium silicate or sodium silicate alone. The contents of the flavonoids and phenolic acids (free, esters, and glycosides) were determined using HPLC-ESI-MS/MS. Phenolic compounds were released from the esters after acid hydrolysis and from the glycosides using alkaline hydrolysis. Quercetin, kaempferol, (‒)-epicatechin, naringenin, apigenin, and luteolin derivatives were found in broccoli and radish sprouts, while derivatives of iso-rhamnetin, orientin, and vitexin were not present at measurable levels. The flavonoid contents, especially derivatives of quercetin, were considerably higher in the broccoli sprouts than in the radish sprouts. The quantitatively major phenolic acid content in the sprouts of both species was found to be p-hydroxybenzoic acid. Its content in the radish sprouts was several times higher than in the broccoli sprouts. The total flavonoid content of broccoli sprouts was 507-734 µg/g DW, while that of the radish sprouts ranged from 155 µg/g DW to 211 µg/g DW. In contrast, total phenolic acids were higher in radish sprouts, ranging from 11,548 to 13,789 µg/g DW, while in broccoli sprouts, they ranged from 2652 to 4527 µg/g DW, respectively. These differences resulted radish sprouts having higher antioxidant activity compared to broccoli sprouts. The applied elicitors increased the content of the total phenolic acids and the antioxidant activity of radish and broccoli sprouts, while they decreased the level of the total flavonoids in broccoli sprouts.


Assuntos
Brassica/metabolismo , Ácido Edético/metabolismo , Polifenóis/biossíntese , Raphanus/metabolismo , Silicatos/metabolismo , Sementes/metabolismo
19.
J Indian Prosthodont Soc ; 21(3): 295-303, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34380818

RESUMO

Aims: The purpose of this study is to compare and evaluate the failure modes and load-bearing capacity of different surface-treated polyether ether ketone (PEEK) copings when veneered with lithium di-silicate with that of PEEK veneered with composite. Settings and Design: In vitro; comparative study. Materials and Methods: Congruently anatomically shaped single unit PEEK copings (n = 40) were fabricated by scanning a prepared typodont tooth. The PEEK copings were subdivided among four groups (n = 10/group). Among all, one group of PEEK coping was veneered with Urethane dimethacrylate (UDMA)-based composite and other groups were veneered with lithium-di-silicate after different surface treatment on peek copings, i.e., (i) composite veneered PEEK fixed dental prosthesis (FDP) (control group: Group PC), (ii) lithium di-silicate veneered PEEK FDP (no surface treatment: Group PCeN), (iii) lithium di-silicate veneered PEEK FDP (sandblasting with 50 µm alumina: Group PCeS), and (iv) lithium di-silicate veneered PEEK FDP (chemical etching with 98% sulfuric acid: Group PCeE). The load-bearing capacity of all specimens was assessed using a universal test machine. All the samples were loaded till the cracking point and load at that point and failure modes were noted down. Statistical Analysis Used: One-way ANOVA and post hoc Tukey tests. Results: The highest load-bearing capacity was recorded for lithium di-silicate veneered PEEK copings which were chemically etched with 98% sulfuric acid (Group PCeE: 1040.25 ± 77.46) followed by Group PCeS (1017.20 ± 53.70), then Group PC (965 ± 51.57) and least was for Group PCeN (933 ± 97.54). There was a significant reduction in mean load-bearing capacity in Group PCeN (P < 0.05). Conclusions: Veneering of PEEK with pressed lithium di-silicate seems to be a viable clinical option in terms of adequate load-bearing capacity. Lithium di-silicate veneered PEEK FDPs were successful against physiological occlusal forces and are a suitable material for FDPs.


Assuntos
Cetonas , Lítio , Adaptação Psicológica , Benzofenonas , Éteres , Polímeros , Silicatos , Suporte de Carga
20.
Int Endod J ; 54(11): 2025-2043, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34338339

RESUMO

BACKGROUND: Most recently, the biological interactions, that is cytocompatibility, cell differentiation and mineralization potential, between calcium silicate-based biomaterials and periodontal ligament stem cells (PDLSCs) have been studied at an in vitro level, in order to predict their clinical behaviour during endodontic procedures involving direct contact with periodontal tissues, namely root canal treatment, endodontic surgery and regenerative endodontic treatment. OBJECTIVE: The aim of the present systematic review was to present a qualitative synthesis of available in vitro studies assessing the biological interaction of PDLSCs and calcium silicate-based biomaterials. METHODOLOGY: The present review followed PRISMA 2020 guidelines. An advanced database search was performed in Medline, Scopus, Embase, Web of Science and SciELO on 1 July 2020 and last updated on 22 April 2021. Studies assessing the biological interactions of PDLSCs with calcium silicate-based sealers (CSSs) and/or cements (CSCs) at an in vitro level were considered for inclusion. The evaluation of the 'biological interaction' was defined as any assay or test on the cytotoxicity, cytocompatibility, cell plasticity or differentiation potential, and bioactive properties of PDLSCs cultured in CSC or CSS-conditioned media. Quality (risk of bias) was assessed using a modified CONSORT checklist for in vitro studies of dental materials. RESULTS: A total of 20 studies were included for the qualitative synthesis. CSCs and CSSs, as a group of endodontic materials, exhibit adequate cytocompatibility and favour the osteo/cementogenic differentiation and mineralization potential of PDLSCs, as evidenced from the in vitro studies included in the present systematic review. DISCUSSION: The influence of the compositional differences, inclusion of additives, sample preparation, and varying conditions and manipulations on the biological properties of calcium silicate-based materials remain a subject for future research. CONCLUSIONS: Within the limitations of the in vitro nature of the included studies, this work supports the potential use of calcium silicate-based endodontic materials in stem cell therapy and biologically based regenerative endodontic procedures. REGISTRATION: OSF Registries; https://doi.org/10.17605/OSF.IO/SQ9UY.


Assuntos
Ligamento Periodontal , Materiais Restauradores do Canal Radicular , Materiais Biocompatíveis/farmacologia , Compostos de Cálcio/farmacologia , Silicatos/farmacologia , Células-Tronco
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