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1.
Environ Pollut ; 355: 124184, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38782162

RESUMO

While sodium hypochlorite (NaClO) has long been used to disinfect drinking water, concerns have risen over its use due to causing potentially hazardous byproducts. Catalytic ozonation with metal-free catalysts has attracted increasing attention to eliminate the risk of secondary pollution of byproducts in water treatment. Here, we compared the disinfection efficiency and microbial community of catalytic ozone with a type of metal-free catalyst fluorinated ceramic honeycomb (FCH) and NaClO disinfectants under laboratory- and pilot-scale conditions. Under laboratory conditions, the disinfection rate of catalytic ozonation was 3∼6-fold that of ozone when the concentration of Escherichia coli was 1 × 106 CFU/ml, and all E. coli were killed within 15 s. However, 0.65 mg/L NaClO retained E. coli after 30 min using the traditional culturable approach. The microorganism inactivation results of raw reservoir water disinfected by catalytic ozonation and ozonation within 15 s were incomparable based on the cultural method. In pilot-scale testing, catalytic ozonation inactivated all environmental bacteria within 4 min, while 0.65 mg/L NaClO could not achieve this success. Both catalytic ozonation and NaClO-disinfected methods significantly reduced the number of microorganisms but did not change the relative abundances of different species, i.e., bacteria, viruses, eukaryotes, and archaea, based on metagenomic analyses. The abundance of virulence factors (VFs) and antimicrobial resistance genes (ARGs) was detected few in catalytic ozonation, as determined by metagenomic sequencing. Some VFs or ARGs, such as virulence gene 'FAS-II' which was hosted by Mycobacterium_tuberculosis, were detected solely by the NaClO-disinfected method. The enriched genes and pathways of cataO3-disinfected methods exhibited an opposite trend, especially in human disease, compared with NaClO disinfection. These results indicated that the disinfection effect of catalytic ozone is superior to NaClO, this finding contributed to the large-scale application of catalytic ozonation with FCH in practical water treatment.


Assuntos
Cerâmica , Desinfetantes , Desinfecção , Água Potável , Ozônio , Hipoclorito de Sódio , Purificação da Água , Ozônio/química , Desinfetantes/farmacologia , Água Potável/microbiologia , Água Potável/química , Desinfecção/métodos , Cerâmica/química , Purificação da Água/métodos , Hipoclorito de Sódio/farmacologia , Hipoclorito de Sódio/química , Catálise , Halogenação , Escherichia coli/efeitos dos fármacos , Projetos Piloto , Microbiologia da Água , Bactérias/efeitos dos fármacos
2.
Tissue Cell ; 88: 102391, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38657320

RESUMO

INTRODUCTION: BioRoot Flow (BRF) is a novel premixed bioceramic sealer indicated for endodontic treatments, but the biological and immunomodulatory effects of this endodontic sealer on human periodontal ligament stem cells (hPDLSCs) have not been elucidated. METHODS: To ascertain the biological impact of BRF, TotalFill BC Sealer (TFbc), and AH Plus (AHP) on human Periodontal Ligament Stem Cells (hPDLSCs), assessments were conducted to evaluate the cytocompatibility, cellular proliferation, migratory capacity, osteo/cementogenic differentiation potential, the ability to form mineralized nodules, and the immunomodulatory characteristics of hPDLSCs following treatment with these endodontic sealers. RESULTS: Biological assays showed adequate cell metabolic activity and cell migration in BRF, while SEM assay evidenced that TFbc and BRF groups demonstrated a superior cell adhesion process, including substrate adhesion, cytoskeleton development, and spreading on the niche-like structures of the cement as compared to the AHP group. TFbc and BRF-treated groups exhibited a significantly lower IL6 and IL8 production than AHP (* p <.05). The bioceramic sealers stimulated heightened expression of BSP, CEMP-1, and CAP genes within a 7-14 day period. Notably, BRF and TFbc demonstrated a significant enhancement in the mineralization of hPDLSCs when compared to the negative control. Among these, cells treated with BRF showed a more substantial accumulation of calcium (*** p < .001). CONCLUSIONS: Taken together, these findings indicate that BRF can potentially enhance cell differentiation by promoting the expression of essential genes related to bone and cement formation. In addition, BRF and TFbc displayed anti-inflammatory effects.


Assuntos
Anti-Inflamatórios , Diferenciação Celular , Humanos , Diferenciação Celular/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Materiais Restauradores do Canal Radicular/farmacologia , Ligamento Periodontal/citologia , Ligamento Periodontal/efeitos dos fármacos , Ligamento Periodontal/metabolismo , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Proliferação de Células/efeitos dos fármacos , Cerâmica/farmacologia , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/química , Movimento Celular/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos
3.
Environ Sci Pollut Res Int ; 31(12): 18856-18870, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38351356

RESUMO

Solid waste management is a critical issue worldwide. Effectively utilizing these solid waste resources presents a viable solution. This study focuses on Iron ore tailings (IOTs), a solid waste generated during iron ore processing, which can be used as supplementary cementitious materials (SCMs) but have low reactivity, hindering their large-scale application in concrete production. To address this, ternary SCMs were prepared using ceramic powder (CP) and steel slag (SS) to enhance the performance of concrete incorporating IOTs. The study found that the synergistic effect of CP and SS significantly improved the compressive strength of concrete, with a notable increase of up to 21% compared to concrete with IOTs alone. Mercury intrusion porosimetry (MIP) and backscattering electron (BSE) analyses revealed that the ternary SCMs significantly optimized the characteristics of the interfacial transition zone (ITZ), which in turn enhanced the compressive properties of the concrete. This contributed to maintaining the structural integrity of the concrete, even amidst variations in the pore structure. Importantly, the incorporation of ternary SCMs led to a 23% reduction in carbon emissions, from 400.01 kg CO2/m3 to 307.48 kg CO2/m3, and elevated eco-strength efficiency from 0.1 to 0.14. The study highlights the role of multi-material synergy in developing composite SCMs systems, fostering the sustainable advancement of green building materials.


Assuntos
Dióxido de Carbono , Aço , Pós , Resíduos Sólidos , Cerâmica , Ferro
4.
Arch Orthop Trauma Surg ; 144(1): 459-464, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37615684

RESUMO

INTRODUCTION: The role of different femoral head materials for total hip arthroplasty (THA) has been widely studied in the context of wear properties and corrosion. Cobalt chrome (CoCr) femoral heads are commonly used as a standard of comparison to other materials such as ceramic and oxidized zirconium (OxZi). This study aims to evaluate the impact of femoral head material on clinical outcomes in elective primary THA patients. METHODS: Retrospective analysis of THA patients within the Medicare claims database between October 2017 and September 2020 using diagnosis-related group codes was conducted. Information collected included sex, age, Charlson Comorbidity Index, and femoral head type. Patients with CoCr femoral heads were compared against patients with either OxZi or ceramic femoral heads using 1:1 propensity score matching. Z-testing and Chi-square analysis were used to determine between-group significance. RESULTS: In total, 112,960 elective THA patients were included, with 56,480 in OxZi or ceramic and 56,480 in CoCr. Readmission rates were lower in patients that received OxZi or ceramic femoral heads at 30-day (p < 0.0001), 60-day (p < 0.0001), and 90-day postoperatively (p < 0.0001) compared to CoCr. Mortality rates were also lower in patients that received OxZi or ceramic femoral heads at 30-day (p = 0.004), 60-day (p = 0.018), and 90-day postoperatively (p = 0.009) compared to CoCr. CONCLUSION: CoCr femoral heads had higher rates of readmissions and mortality compared to OxZi or ceramic. Further analysis of bearing surface combinations and sub-group analyses to determine significance between-group differences is needed. LEVEL III EVIDENCE: Retrospective analysis.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Humanos , Idoso , Estados Unidos/epidemiologia , Cabeça do Fêmur/cirurgia , Readmissão do Paciente , Estudos Retrospectivos , Fatores de Tempo , Desenho de Prótese , Medicare , Ligas de Cromo , Zircônio , Cerâmica , Falha de Prótese
5.
Clin Implant Dent Relat Res ; 26(2): 333-342, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37984494

RESUMO

BACKGROUND: Lithium disilicate can be reliable when restoring implants in the esthetic zone. However, it has a high elastic modulus. This might increase the amount of forces transmitted to the crestal bone. AIM OF THE STUDY: To evaluate the crestal bone loss and peri-implant periodontal parameters of polymer infiltrated ceramic network compared to lithium disilicate implant-supported hybrid abutment crowns after 12 months of follow-up. METHODOLOGY: 44 patients were enrolled. They were randomly assigned into two groups (n = 22). The first group received 22 implants restored with polymer-infiltrated ceramic network (Vitaenamic) hybrid abutment crowns. The second group received 22 implants restored with lithium disilicate (e.max) hybrid abutment crowns over immediately placed implants in the esthetic zone. Periapical radiographs were taken immediately after prosthetic placement and 1 year later utilizing a parallel technique, to assess crestal bone loss. Periodontal parameters were assessed after 1 year. RESULTS: Regarding crestal bone loss, a comparison between group I (Vitaenamic) and group II (e.max) was made by using an Independent t-test, which showed an insignificant difference between them (p > 0.05). A comparison between groups I and II revealed insignificant differences regarding periodontal parameters (probing depth, bleeding on probing, visible plaque, and suppuration). CONCLUSIONS: Regarding bone stability and periodontal parameters, polymer infiltrated ceramic network and lithium disilicate hybrid abutment crowns showed comparable results. Both materials showed clinically acceptable hard and soft tissue responses.


Assuntos
Implantes Dentários , Estética Dentária , Humanos , Porcelana Dentária , Coroas , Cerâmica , Desenho Assistido por Computador , Zircônio
6.
J Environ Manage ; 345: 118894, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37659359

RESUMO

Algal-bacterial membrane photobioreactor (AMPBR) is proven as a highly energy-efficient process for treating domestic wastewater. This study compared the application of polymeric micro-membrane (PMM) and a low-cost ceramic membrane (LCM) to the AMPBR process for treating domestic wastewater with low and high organic pollution levels. Experiments were conducted over 57 days using two PMM-AMPBRs and two LCM-AMPBRs, operating on a 12-h dark/light cycle in a continuous mode. Simulated wastewater containing varying levels of chemical oxygen demand (COD) was fed to reactors for a consistent hydraulic residence time (HRT) of 7 d and a flux rate of 100 L/m2/d. PMM and LCM-AMPBRs demonstrated efficient wastewater treatment capabilities, achieving COD removal rates exceeding 94% and 95% for high and low COD loadings, respectively. PMM-AMPBR achieved 54.1% TN removal at low COD loading, while LCM-AMPBR achieved 57.2%. These removal efficiencies decreased to 45.6% and 47.0% under high COD loading. Total Phosphorus (TP) removal reached 29-33% for PMM-AMPBRs and 21-24% for LCM-AMPBRs, irrespective of COD loading. LCM-AMPBRs showed significantly lower fouling frequency than PMM-AMPBRs. The biomass production rate decreased with increasing COD loading and achieved 40 mg/L/d at low COD loading for both AMPBRs. Net energy return (NER) values for both AMPBRs were close to 0.87, indicating them as energy-efficient processes. Considering the cost-effectiveness and comparable performance, LCM-AMPBR could be a viable alternative to PMM-AMPBR for wastewater treatment, particularly under low COD loading conditions.


Assuntos
Águas Residuárias , Purificação da Água , Fotobiorreatores/microbiologia , Membranas , Cerâmica , Reatores Biológicos , Eliminação de Resíduos Líquidos
7.
J Mater Chem B ; 11(31): 7502-7513, 2023 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-37458109

RESUMO

Magnetic bioactive glass-ceramic (MGC) powders with nominal compositions of (45 - x)SiO224.5CaO24.5Na2O6P2O5xFe2O3 (x = 2, 4, 6, 8, 10, and 15 wt%) have been synthesized by a sol-gel route by systematically substituting silicon dioxide with iron oxide in Hench's 45S5 glass composition. Powder X-ray diffraction studies revealed a variation in the percentage of combeite (Ca2Na2Si3O9), magnetite (Fe3O4), and hematite (Fe2O3) nanocrystalline phases in MGC powders as a function of composition. Zeta potential measurements showed that MGC containing up to 10 wt% iron oxide formed stable suspensions. The saturation magnetization and heat generation capacity of MGC fluids increased with an increase in iron oxide content. Degradation of MGC powders was investigated in phosphate buffered saline (PBS). The in vitro bioactivity of the MGC powders taken in pellet form was confirmed by observing the pH variation as well as hydroxyapatite layer (HAp) formation upon soaking in modified simulated body fluid. These studies showed a decrement in the overall bioactivity in samples with high iron oxide content due to the proportional decrease in the silanol group. Monitoring the proliferation of MG-63 osteoblast cells in Dulbecco's Modified Eagle Medium (DMEM) revealed that MGC with up to 10 wt% iron oxide exhibited acceptable viability. The systematic study revealed that the MGC with 10 wt% iron oxide exhibited optimal cell viability, magnetic properties and induction heating capacity, which were better than those of FluidMag-CT, which is used for hyperthermia treatment.


Assuntos
Cerâmica , Durapatita , Pós/química , Durapatita/química , Cerâmica/química
8.
Dent Mater ; 39(7): 669-676, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37230861

RESUMO

OBJECTIVES: The aim of this study was to evaluate the mechanical properties and cost efficiency of direct ink writing (DIW) printing of two different zirconia inks compared to casting and subtractive manufacturing. METHODS: Zirconia disks were manufactured by DIW printing and the casting process and divided into six subgroups (n = 20) according to sintering temperatures (1350 °C, 1450 °C and 1550 °C) and two different ink compositions (Ink 1, Ink 2). A CAD/CAM-milled high strength zirconia (3Y-TZP) was added as reference group. The biaxial flexural strength (BFS) was measured using the piston-on-three-balls test. X-ray-diffraction (XRD) was used for microstructural analysis. The cost efficiency was compared for DIW printing and subtractive manufacturing by calculation of the manufacturing costs of one dental crown. RESULTS: Using XRD, monoclinic and tetragonal phases were detected for Ink 1, for all other groups no monoclinic phase was detected. The CAD/CAM-milled ceramic showed a significantly higher BFS than all other groups. The BFS of Ink 2 was significantly higher than the BFS of Ink 1. At a sintering temperature of 1550 °C the mean BFS of the printed Ink 2 was 822 ± 174 MPa. The BFS of the cast materials did not show a significantly higher BFS than the corresponding printed group for any tested parameter-set. The manufacturing costs of DIW printed crowns are lower than the manufacturing costs of CAD/CAM-milled crowns. CONCLUSION: DIW has a high potential to replace subtractive processes for dental applications, as it shows promising mechanical properties for appropriate ink compositions and facilitates a highly cost effective production.


Assuntos
Cerâmica , Tinta , Teste de Materiais , Propriedades de Superfície , Cerâmica/química , Zircônio/química , Desenho Assistido por Computador , Impressão Tridimensional , Materiais Dentários/química
9.
J Mech Behav Biomed Mater ; 143: 105904, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37178637

RESUMO

Stereolithography (SLA) is gaining vast popularity in the development of three-dimensional parts with customized materials for tissue engineering applications. Consequently, developing customized materials like bio-composites (bio-polymers and bio-ceramics) is the basic pillar that meets the application requirement. Photo-crosslinkable poly(ethylene glycol) diacrylate (PEGDA) has outstanding biocompatibility and biophysical properties for tissue engineering. But, because of its poor mechanical properties, its scope is limited to load-bearing applications. This research aims to enhance the mechanical and tribological properties of PEGDA by reinforcing Vitreous Carbon (VC) bioceramic. Therefore, 1 to 5 wt % of VC have been added in PEGDA and developed novel PEGDA/VC composite resins for SLA. The rheological and sedimentation test have been performed to check the suitability for SLA printing. Afterward, printed materials have been characterized by fourier transform infrared spectrometer, X-ray diffraction, thermogravimetric analysis, optical profilometer, and scanning electron microscope. Moreover, tensile compression, flexural, and tribological properties have been evaluated. It was found that the addition of VC in PEGDA enhanced its mechanical, thermal, and tribological properties. Besides, a life cycle assessment of materials and energy resources in SLA process has been performed to investigate the environmental impact.


Assuntos
Polietilenoglicóis , Impressão Tridimensional , Animais , Teste de Materiais , Cerâmica , Estágios do Ciclo de Vida
10.
Food Addit Contam Part B Surveill ; 16(3): 209-218, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37102322

RESUMO

Ceramic products are among the most frequently used food contact materials. Health risks associated with ceramic tableware usually arise from the migration of heavy metals. In this study, 767 pieces of ceramic tableware of different shapes and types were collected across China, and the migration levels of 18 elements were determined using inductively coupled plasma mass spectrometry. Migration tests were conducted according to the Chinese National Food Safety Standard - Ceramic Ware (GB 4806.4) with microwaveable and non-microwavable samples under different conditions. The food consumption of consumers via different shapes of ceramic tableware was obtained through a self-reported web-based survey, and the estimated dietary intakes of the studied elements were calculated accordingly. The exposure assessment showed that certain metals leached from the ceramic tableware at levels of concern. In addition, the applicability of the migration experiment conditions for microwaveable ceramic ware in GB 4806.4 needs to be further investigated.


Assuntos
Contaminação de Alimentos , Metais Pesados , Humanos , Contaminação de Alimentos/análise , Metais Pesados/análise , Inocuidade dos Alimentos , Medição de Risco , Cerâmica/química , China
11.
Nature ; 614(7947): 287-293, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36725928

RESUMO

The ability of the ancient Egyptians to preserve the human body through embalming has not only fascinated people since antiquity, but also has always raised the question of how this outstanding chemical and ritual process was practically achieved. Here we integrate archaeological, philological and organic residue analyses, shedding new light on the practice and economy of embalming in ancient Egypt. We analysed the organic contents of 31 ceramic vessels recovered from a 26th Dynasty embalming workshop at Saqqara1,2. These vessels were labelled according to their content and/or use, enabling us to correlate organic substances with their Egyptian names and specific embalming practices. We identified specific mixtures of fragrant or antiseptic oils, tars and resins that were used to embalm the head and treat the wrappings using gas chromatography-mass spectrometry analyses. Our study of the Saqqara workshop extends interpretations from a micro-level analysis highlighting the socio-economic status of a tomb owner3-7 to macro-level interpretations of the society. The identification of non-local organic substances enables the reconstruction of trade networks that provided ancient Egyptian embalmers with the substances required for mummification. This extensive demand for foreign products promoted trade both within the Mediterranean8-10 (for example, Pistacia and conifer by-products) and with tropical forest regions (for example, dammar and elemi). Additionally, we show that at Saqqara, antiu and sefet-well known from ancient texts and usually translated as 'myrrh' or 'incense'11-13 and 'a sacred oil'13,14-refer to a coniferous oils-or-tars-based mixture and an unguent with plant additives, respectively.


Assuntos
Embalsamamento , Múmias , Humanos , Antigo Egito , Embalsamamento/economia , Embalsamamento/história , Embalsamamento/métodos , Cromatografia Gasosa-Espectrometria de Massas , História Antiga , Múmias/história , Resinas Vegetais/análise , Resinas Vegetais/história , Cerâmica/química , Cerâmica/história , Alcatrões/análise , Alcatrões/história , Óleos de Plantas/análise , Óleos de Plantas/história , Região do Mediterrâneo , Clima Tropical , Florestas , Traqueófitas/química , Comércio/história
12.
Int J Comput Dent ; 26(1): 37-47, 2023 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-36825566

RESUMO

AIM: The present study aimed to evaluate the marginal and internal fit of lithium disilicate crowns at various locations. MATERIALS AND METHODS: A typodont maxillary left first molar was prepared for a lithium disilicate crown, scanned, and a master die fabricated. Three groups were created according to fabrication method (n = 10): conventional impression and press method (group C); scanning of definitive cast and milling method (group D); and intraoral scanning and milling method (group I). Assessment was performed using the triple-scan protocol. At the buccopalatal and mesiodistal sections, the absolute marginal discrepancy (AMD), marginal gap (MG), axial internal gap (AI), and line angle internal gap (LI) were measured. One-way analysis of variance (ANOVA) and post hoc Tukey HSD tests were used for statistical analysis (α = 0.05). RESULTS: AMD values were significantly lower in group C than in groups D and I (P < 0.05). MG values in group C were significantly lower than those in the buccal and distal areas in group D and all areas in group I (P < 0.05). AI values in the buccal and palatal areas in group D were significantly lower than those in the mesial and distal areas in group D and all areas in groups C and I (P < 0.05). LI values were significantly lower in group C than in groups D and I (P < 0.05). CONCLUSION: All three methods were clinically acceptable except for the marginal fit of the intraoral scanning and milling method, which was on the borderline of a clinically acceptable fit. (Int J Comput Dent 2023;26(1): 37-0; doi: 10.3290/j.ijcd.b3818305).


Assuntos
Cerâmica , Desenho Assistido por Computador , Humanos , Planejamento de Prótese Dentária/métodos , Adaptação Marginal Dentária , Técnica de Moldagem Odontológica , Porcelana Dentária , Coroas
13.
Environ Sci Pollut Res Int ; 30(16): 45872-45887, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36707477

RESUMO

Field-scale application of the microbial fuel cell (MFC) technology faces a major constraint due to the widely used high-cost proton exchange membrane Nafion, prompting lately, the development of ceramic membranes using different clay minerals. In the present study, the characteristics and applicability of a novel ceramic membrane fabricated using potter's clay (C) blended with varying proportions (0, 5, 10, and 20 wt%) of fly ash (FA), designated as CFA0, CFA5, CFA10, and CFA20, were assessed for cost-effective and sustainable use in MFC. On assessing the properties of the membrane, CFA10 was found to exhibit superior quality with fine pore size distribution (average 0.49 µm) favoring higher water uptake and less oxygen diffusion. The CFA10 membrane showed a maximum proton mass transfer coefficient (4.32 ± 0.04 × 10-5 cm/s) that was about three times that of the control CFA0. The oxygen mass transfer coefficient of CFA10 was 5.13 ± 0.12 × 10-5 cm/s, which was about 40% less than in the control. X-ray diffraction (XRD) analysis of CFA membrane revealed the richness of quartz, which facilitates proton conductance and water retention. The CFA10 membrane fitted MFC demonstrated a peak power output of 4.57 W/m3 (twice that in CFA0) with an average of 80.02 ± 0.86% COD removal and 68.03 ± 0.13% coulombic efficiency in a long-term study indicating its improved applicability and durability. Electrochemical kinetics involving cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) also affirmed the efficacy of CFA10 membrane in MFC showing peak current output of 13.95 mA and low ohmic resistance (74.2 Ω). The novel (CFA10) ceramic membrane amalgamated with the coal fly ash, a waste of concern, shows promise for high MFC performance at a much reduced (98% less) cost that can be used for sustainable scale-up of the technology.


Assuntos
Fontes de Energia Bioelétrica , Purificação da Água , Eletricidade , Cinza de Carvão , Prótons , Argila , Cerâmica , Oxigênio/química , Eletrodos
14.
J Prosthet Dent ; 129(6): 897-905, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34598771

RESUMO

STATEMENT OF PROBLEM: Evidence is limited for the impact of clinical adjustments and polishing on the longevity of glazed lithium disilicate restorations. PURPOSE: The purpose of this in vitro study was to evaluate the influence of surface finishing on the survival and success rates of lithium disilicate restorations based on fatigue resistance and failure mode. MATERIAL AND METHODS: Lithium disilicate (IPS e.max CAD) maxillary premolar crowns (N=54) were cemented on a dentin analog. The restorations were divided into 3 groups: overglaze (OG), abrasion (GA), and abrasion and polishing (AP). The crowns were submitted to cyclic fatigue in 37 oC water at 100 N and 2 Hz in 2 lifetimes. The load was applied to the occlusal surface by using anatomic pistons to simulate a clinical tripod occlusal contact. After cycling, the crowns were examined for failure (cracking, chipping, or catastrophic fractures) under optical and scanning electron microscopy. Cracking was considered either a structural failure (success analysis) or a survival (clinical criteria - survival analysis). Data were analyzed by using the log rank Kaplan-Meier and Holm-Sidak tests (α=.05). RESULTS: Surface finishing had no influence on the structural integrity of lithium disilicate, with similar success rates (P=.720). The calculated survival rate was higher for AP than that for other groups (P=.028). Cracking was found for GA and AP crowns, mostly initiating from the external surface. Chipping occurred in all experimental groups, and AP crowns did not show catastrophic failures. CONCLUSIONS: Although surface treatments had no influence on the success of lithium disilicate, polishing showed a positive effect on the survival rate of the crowns based on the clinical implications of cracking (no need for replacement).


Assuntos
Porcelana Dentária , Falha de Restauração Dentária , Teste de Materiais , Porcelana Dentária/química , Coroas , Cerâmica/química , Desenho Assistido por Computador
15.
J Prosthet Dent ; 129(1): 150-159, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34330531

RESUMO

STATEMENT OF PROBLEM: In computer-aided design and computer-aided manufacturing (CAD-CAM) dentistry, the CAD of the prosthesis represents the clinical prerequisite design to restore the treated tooth. However, how closely the CAM prosthesis shape matches the CAD, particularly in relation to different materials, is unclear. PURPOSE: The purpose of this in vitro study was to evaluate onlays designed and manufactured with the same CAD-CAM system but manufactured with different materials. MATERIAL AND METHODS: A single standard tessellation language (STL) model was used to produce 6 composite resin onlays, 6 leucite glass-ceramic onlays, and 6 lithium disilicate glass-ceramic onlays. The onlays were digitized by using an X-ray microtomographic protocol with a metrological calibration. The CAD model was then compared with the scans of the different onlays. An analysis by region of interest was then carried out to assess the accuracy and reliability of the dimensional accuracy. RESULTS: The composite resin and the lithium disilicate glass-ceramic had the best dimensional accuracy. The leucite glass-ceramic exhibited a lack of trueness linked to consistent overmilling. The composite resin had less peripheral chipping than the glass-ceramics. CONCLUSIONS: The composite resin and the lithium disilicate glass-ceramic material exhibited satisfactory dimensional accuracy. Milling the glass-ceramic before crystallization considerably improved dimensional accuracy.


Assuntos
Cerâmica , Porcelana Dentária , Reprodutibilidade dos Testes , Teste de Materiais , Cerâmica/química , Restaurações Intracoronárias , Resinas Compostas/química , Desenho Assistido por Computador , Materiais Dentários
16.
Environ Sci Pollut Res Int ; 30(10): 25382-25401, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35836050

RESUMO

Health monitoring of structures using techniques based on the smart material is an innovative concept that is exploding technological revolutions in the field of civil engineering. The electro-mechanical impedance (EMI) technique is used for structural health monitoring (SHM) and to investigate the damages in the structures. The bacterial incorporation in concrete produces calcite material through metabolism process in presence of moisture and carbon dioxide, which improves the mechanical properties of concrete. Hence, its application in construction of the buildings will improve the health of structures. In this research paper, dynamic behaviour of the bacterial concrete was investigated numerically. The beams of size 700 × 150 × 150 mm of bacterial concrete and control concrete were modelled using finite element-based package ANSYS19. The beam of bacterial concrete was simulated as per the characteristics of the materials produced after the bacterial metabolism reactions. The EMI technique was applied to investigate the health of these beams. Admittance (conductance and susceptance) signatures were determined using piezo-ceramic lead zirconate titanate (PZT) sensors installed at mid-point on the top surface of concrete beams. The beams were exposed to dynamic loading and the intensity of dynamic loading was increased in four sub-steps. For the quantification of strength development in the concrete beam, the root mean square deviation (RMSD) statistical index had been applied. It was observed that the bacterial concrete beam has more resistance to the dynamic loading.


Assuntos
Carbonato de Cálcio , Dióxido de Carbono , Impedância Elétrica , Cerâmica , Tecnologia
17.
Waste Manag ; 157: 269-278, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36580882

RESUMO

The problem of waste generation has grown because of the need to extract natural resources, obtain materials, and consume energy to meet current societal needs. Many studies have been conducted worldwide in favor of technological solutions for the valorization of industrial waste (IW) but few discussed relevant data for effective recovery. In this study, a case study of ceramic shell waste (CSW) was performed using, for the first time, a waste valorization system based on the classification, potentiality, quantity/viability, and applicability criteria (CPQvA) in a specific region (Brazil). CPQvA is a multicriteria decision-making system that acts as a guide to help managers and researchers connect the potential of IW with the feasibility of its application in a product or another process. Using the proposed systematic criteria, it was possible to demonstrate similarities and differences in waste applications. Thirteen possible products made from CSW were analyzed based on all the parameters of CPQvA. Ceramic filters and refractory aggregates were the most viable products. Creating public policies that encourage the use of waste as a raw material could make the precision casting industry process cleaner and the economy more circular.


Assuntos
Cerâmica , Gerenciamento de Resíduos , Resíduos Industriais , Política Pública , Brasil
18.
Waste Manag ; 157: 301-311, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36584494

RESUMO

Municipal solid waste (MSW) production in the world has increased by 60 % in recent years. Incineration of MSW reduces their volume in conjunction with energy recovery. Incineration produces two residues, namely bottom ash (BA) and fly ash (FA), with high concentration of heavy metals and organic pollutants, especially for FA, making them an environmental concern. Vitrification is a costly, highly safe high temperature treatment, ensuring encapsulation of heavy metals. FA vitrification requires a source of silica to be able to get vitrified. In this study, we have proposed valorizing treated (vitrified) FA through the production of porous glass-ceramics, subsequently to MSWI. The entire process, from incineration to glass-ceramics production, was evaluated for several scenarios by Life Cycle Assessment (LCA) using Sima Pro 9.0. Three main scenarios were analysed; each one considering a different silica source: bottom ash (BA), glass cullet (G) and silica sand (S), and for each scenario, three thermal recovery subscenarios were assumed: no thermal recovery used to heat FA prior to vitrification (N), heating FA prior to vitrification using incineration gases thermal recovery (T) and methane-combustion-aided thermal recovery, which exploits methane combustion to further increase the gases temperature (M). Results proved that vitrification was a technically feasible and environmentally-energetically sustainable technology. The result indicates that the most eco-sustainable scenario was using bottom ashes as a silica source together with methane-combustion-aided recovery: 0.467 kgCO2,eq, 5.83 × 10-8 carcinogenic-CTUh and 9.26 MJ required per kg of glass-ceramics produced.


Assuntos
Metais Pesados , Eliminação de Resíduos , Animais , Cinza de Carvão/química , Metano/análise , Dióxido de Silício , Porosidade , Incineração/métodos , Metais Pesados/análise , Resíduos Sólidos/análise , Gases/análise , Cerâmica , Estágios do Ciclo de Vida , Carbono , Material Particulado
19.
J Esthet Restor Dent ; 34(8): 1247-1262, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36120840

RESUMO

OBJECTIVE: To assess the clinical outcome of three esthetic implant-supported crown systems fabricated with semi-digital workflow and their influence on the clinical outcome of dental implants. MATERIAL AND METHODS: A total of 30 participants had received dental implants restoring missing maxillary first/second premolars. After 6 weeks, customized zirconia abutments were early loaded. Two months later, the definitive crowns were fabricated using semi-digital workflow and cemented. According to the crown material, 3 groups were randomly allocated; group (Z): ultrahigh-translucent monolithic zirconia, group (C): resin-matrix ceramic and group (P): polyetherketoneketone veneered with light-cured composite resin. Clinical outcomes including the survival and success rates were evaluated at baseline, 6, 12, 18, and 24 months. RESULTS: The survival rate for all studied groups was 100%, while their success rate was 100% for group (Z) and 90% for group (C) and group (P). Based on the functional implant prosthodontic score, a statistically significant difference was detected between group (Z) and group (P) (p < 0.001) as well as between group (C) and group (P) (p = 0.01). CONCLUSIONS: The zirconia group had the most favorable clinical behavior, while the polyetherketoneketone had the least. All crown systems had comparable success rates with similar values of the peri-implant marginal bone loss. CLINICAL SIGNIFICANCE: Using semi-digital workflow, ultrahigh-translucent monolithic zirconia, resin-matrix ceramic and polyetherketoneketone veneered with light-cured composite resin can be considered as favorable implant-supported crowns. The implant-supported crown system based on polyetherketoneketone veneered with light-cured composite resin is counted as a promising esthetic and restorative option.


Assuntos
Implantes Dentários , Humanos , Cerâmica , Resinas Compostas , Desenho Assistido por Computador , Coroas , Dente Suporte , Prótese Dentária Fixada por Implante , Falha de Restauração Dentária , Estética Dentária , Estudos Prospectivos , Fluxo de Trabalho , Zircônio
20.
Niger J Clin Pract ; 25(8): 1324-1331, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35975382

RESUMO

Background and Aims: Evaluation of the optical properties of restorative materials is an important parameter for identifying clinical success. The aim of this study was to compare the translucency of contemporary resin-matrix ceramics (RMCs) and to evaluate the effect of cement shade on the final color of RMCs indicated for laminate veneers and full crowns. Materials and Methods: A hundred A2 shade RMC specimens were fabricated by using Mazic Duro (MD), CAMouflage NOW (CN), KZR-CAD HR2 (KZR), Grandio Block (GB), and Brilliant Crios (BC) at 0.7-mm and 1.5-mm thicknesses (n = 10). A2 shade composite resin was used for the foundation structure. Twenty resin-cement specimens were prepared from A2 and translucent shades at 0.1-mm thickness. Interchangeably, the foundation-cement-resin matrix ceramic assemblies were created with optical gel. The color coordinates were recorded using a spectrophotometer. After calculating translucency parameter (TP00) and color difference (ΔE00) values, data were analyzed statistically (P = 0.05). Results: TP00 values were influenced by RMC type and thickness. TP00 values of RMCs can be listed in descending order as MD>GB = CN>BC=KZR. ΔE00 values were significantly influenced by all parameters and their interactions. MD exhibited higher ΔE00 values among tested RMCs. The effect of A2 cement was not perceived visually while TR cement demonstrated visually perceptible but clinically acceptable values for both laminate veneers and full crowns. As the material thickness decreased, the TP00 and ΔE00 values increased in all RMCs. Conclusions: Clinicians should carefully prefer cement shade and RMC material by contemplating their impact on the optical properties particularly when the restoration is thin.


Assuntos
Cerâmica , Cimentos de Resina , Cerâmica/química , Cor , Cimentos de Ionômeros de Vidro , Humanos , Teste de Materiais , Pigmentação em Prótese , Cimentos de Resina/química , Propriedades de Superfície
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