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1.
Molecules ; 26(4)2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33671148

RESUMO

NaYF4:Er,Yb upconversion luminescent nanoparticles (UCNPs) were prepared by hydrothermal methods at 180 °C for 24 h. The X-ray diffraction (XRD) and TEM (transmission electron microscopy) images show that the resulting 60 nm UCNPs possess a hexagonal structure. In this work, maleic anhydride (MA) was grafted on the surface of UCNPs to induce hydrophilic properties. The photoluminescence spectra (PL) show upconversion emissions centered around 545 nm and 660 nm under excitation at 980 nm. The luminescent inks, including UCNPs@MA, polyvinyl alcohol (PVA), deionized water (DI), and ethylene glycol (EG), exhibit suitable properties for screen printing, such as high stability, emission intensity, and tunable dynamic viscosity. The printed patterns with a height of 5 mm and a width of 1.5 mm were clearly observed under the irradiation of a 980 nm laser. Our strategy provides a new route for the controlled synthesis of hydrophilic UCNPs, and shows that the UCNPs@MAs have great potential in applications of anti-counterfeiting packing.


Assuntos
Fluoretos/química , Química Verde , Tinta , Luminescência , Anidridos Maleicos/química , Nanopartículas/química , Análise Espectral , Itérbio/química , Ítrio/química , Érbio/química , Fenômenos Ópticos , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier , Vibração , Difração de Raios X
2.
Ecotoxicol Environ Saf ; 214: 112113, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33690006

RESUMO

The main purpose of this work is to thoroughly describe the implementation protocol of laser-induced breakdown spectroscopy (LIBS) method in the plant analysis. Numerous feasibility studies and recent progress in instrumentation and trends in chemical analysis make LIBS an established method in plant bioimaging. In this work, we present an easy and straightforward phytotoxicity case study with a focus on LIBS method. We intend to demonstrate in detail how to manipulate with plants after exposures and how to prepare them for analyses. Moreover, we aim to achieve 2D maps of spatial element distribution with a good resolution without any loss of sensitivity. The benefits of rapid, low-cost bioimaging are highlighted. In this study, cabbage (Brassica oleracea L.) was treated with an aqueous dispersion of photon-upconversion nanoparticles (NaYF4 doped with Yb3+ and Tm3+ coated with carboxylated silica shell) in a hydroponic short-term toxicity test. After a 72-hour plant exposure, several macroscopic toxicity end-points were monitored. The translocation of Y, Yb, and Tm across the whole plant was set by employing LIBS with a lateral resolution 100 µm. The LIBS maps of rare-earth elements in B.oleracea plant grown with 50 µg/mL nanoparticle-treated and ion-treated exposures showed the root as the main storage, while the transfer via stem into leaves was minimal. On the contrary, the LIBS maps of plants exposed to the 500 µg/mL nanoparticle-treated and ion-treated uncover slightly different trends, nanoparticles as well as ions were transferred through the stem into leaves. However, the main storage organ was a root as well.


Assuntos
Brassica/metabolismo , Fluoretos/administração & dosagem , Nanopartículas/administração & dosagem , Dióxido de Silício/administração & dosagem , Túlio/toxicidade , Itérbio/administração & dosagem , Ítrio/administração & dosagem , Lasers , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Caules de Planta/metabolismo , Análise Espectral
3.
Adv Clin Exp Med ; 30(1): 7-15, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33529502

RESUMO

BACKGROUND: Reduced tooth structure in the pediatric and adolescent population is frequently restored with prefabricated zirconia crowns. On permanent teeth, these restorations may need to be removed and replaced with permanent restorations. OBJECTIVES: To explore and compare the use of 2 high-powered erbium lasers for removing prefabricated zirconia crowns from molar teeth as a non-invasive alternative to rotary instruments. MATERIAL AND METHODS: Twenty-five permanent molars were prepared to dentin and prefabricated all-ceramic zirconia crowns were fitted and cemented with resin modified glass ionomer (RMGI) cement. The teeth were randomly assigned into one of the 2 retrieval treatment groups: the erbium-doped yttrium, aluminum and garnet (Er:YAG) laser group (G1; n = 12) or the erbium, chromium-doped yttrium, scandium, gallium and garnet laser (Er,Cr:YSGG) laser group (G2; n = 13). The laser operating parameters for the Er:YAG laser were 300 mJ, 15 Hz, 4.5 W, and 50-microsecond pulse duration (SSP mode); for the Er,Cr:YSGG laser, they were 4.5 W, 15 Hz, 20 water/20 air, and 5 W, 15 Hz, 50 water/50 air, and 60-microsecond pulse duration (H mode). The experiment was repeated twice. The surface area and the volume of teeth and crowns were measured and the cement space was calculated. The retrieval time and temperature changes were tested and recorded. The data were analyzed with the t-test. The surfaces of the dentin and the crown from each group were further examined using scanning electron microscopy (SEM). RESULTS: The average time for crown removal using the Er:YAG laser was 1 min 32.7 s; for the Er,Cr:YSGG laser it was 3 min 13.9 s (p < 0.0001). The mean temperature changes were 1.41 ±1.36°C for the Er:YAG laser and 2.2 ±0.99°C for the Er,Cr:YSGG laser (p = 0.0321). The SEM examination showed no damage or major structural changes caused by treatment with either erbium-family laser. CONCLUSIONS: Both lasers are effective, non-invasive tools to remove prefabricated zirconia crowns cemented with resin cement and should be considered as viable alternatives to rotary instrumentation.


Assuntos
Lasers de Estado Sólido , Coroas , Humanos , Ítrio , Zircônio
4.
Artigo em Inglês | MEDLINE | ID: mdl-33528455

RESUMO

The purpose of this study was to evaluate the cleaning and surface treatment techniques in the repair of aged and contaminated yttrium oxide-stabilized tetragonal polycrystalline zirconia (Y-TZP). From a total of 80 specimens of Y-TZP, 60 were subjected to aging simulation in a buccal environment with degradation in an autoclave for 24 hours (127°C/1.5 bar) and contaminated with Streptococcus mutans. The surfaces were cleaned with a triple syringe (air/water jet; n = 20) or isopropyl alcohol (n = 20), or by prophylaxis (n = 20) with pumice and water. The remaining 20 specimens comprised the control group. All specimens were then treated with silicatization (n = 10 per group) or adhesive (n = 10 per group) and repaired with composite resin. Analyses of shear strength, failure mode, and roughness were performed by electron microscopy. Data were analyzed by two-way analysis of variance (ANOVA) and t test (α = .05). Statistical significance was set at P < .05. Two-way ANOVA was significant for aging and surface treatments (P = .049), but was not significant for surface cleaning (P = .05). ANOVA results were statistically significant for surface treatments (P < .0001), with higher resistance for the silicatization groups. The failure mode was mostly adhesive for all specimens. The roughness was not significant for aging and control groups (P > .05). Triple-syringe and prophylaxis cleansing followed by silicatization was the most efficient treatment for the repair of aged and contaminated Y-TZP. There is reduced repair efficiency with the aging of Y-TZP.


Assuntos
Resinas Compostas , Colagem Dentária , Idoso , Protocolos Clínicos , Análise do Estresse Dentário , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Cimentos de Resina , Resistência ao Cisalhamento , Propriedades de Superfície , Ítrio , Zircônio
5.
J Prosthet Dent ; 125(4): 693.e1-693.e7, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33431178

RESUMO

STATEMENT OF PROBLEM: Nonthermal argon plasma (NTAP) has been reported to improve the bond strength of resin cements to yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics. However, the effect of the inevitable delay before cementation and after treating Y-TZP ceramics with NTAP is unclear. PURPOSE: The purpose of this in vitro study was to investigate whether delays of 8, 12, and 24 hours between the Y-TZP ceramic treatment with NTAP and the cementation would affect the surface energy and the bond strength of a self-adhesive resin cement to Y-TZP ceramic. MATERIAL AND METHODS: Sixty plates and 50 blocks of 3Y-TZP ceramic were divided into 2 groups (n=30 and n=25): as-sintered (AS) and airborne-particle abraded with 50-µm Al2O3 (APA). These groups were further divided into 5 subgroups (n=6 and n=5) according to the delay between the NTAP treatment and the measurement of surface energy and microtensile bond strength (µTBS) evaluation: (0, 8, 12, and 24 hours). For both 3Y-TZP surface conditions (AS and APA), a control group without NTAP treatment was used (ASC and APAC). The surface energy (SE) was evaluated with a goniometer and the 3Y-TZP elemental composition with X-ray photoelectron spectroscopy (XPS). For the µTBS test, the 3Y-TZP ceramic blocks were cemented to composite resin blocks with a self-adhesive resin cement. After storage in distilled water at 37 °C for 24 hours, the 3Y-TZP-composite resin blocks were sectioned into beams and submitted to a µTBS test. Data were submitted to 2-way ANOVA and the Tukey HSD test (α=.05). RESULTS: For the AS group, NTAP increased the SE irrespective of the delay before measurement: ASC<0 hour=8 hours=12 hours=24 hours (P<.05). For the APA group, except after 12 hours, NTAP also increased the surface energy (P<.05). XPS analysis showed an increase in the oxygen/carbon ratio after NTAP treatment for both groups. For the AS group, NTAP increased the µTBS after 0, 8, and 12 hours (P<.05), whereas for the APA group this occurred only after 8 hours (P<.05). For the AS and APA groups, the highest µTBS was reached after 8 hours (P<.05). CONCLUSIONS: Treatment of 3Y-TZP ceramic with NTAP improved the SE and increased the µTBS of self-adhesive resin cement to 3Y-TZP ceramic. These effects were time dependent, with better results at 8 hours after NTAP treatment.


Assuntos
Colagem Dentária , Gases em Plasma , Argônio , Cimentação , Cerâmica , Cimentos Dentários , Análise do Estresse Dentário , Teste de Materiais , Cimentos de Resina , Propriedades de Superfície , Ítrio , Zircônio
6.
Ecotoxicol Environ Saf ; 210: 111862, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33429321

RESUMO

Microcystin-leucine arginine (MC-LR) is a carcinogenic toxin, produced by cyanobacteria. The release of this toxin into drinking water sources can threaten public health and environmental safety. Therefore, effective MC-LR removal from water resources is necessary. In the present study, the hydrothermal method was used to synthesize a novel ternary BiVO4/TiO2/NaY-Zeolite (B/T/N-Z) nanocomposite for MC-LR degradation under visible light. FESEM, FTIR, XRD, and DRS were performed for characterizing the nanocomposite structure. Also, the Response Surface Methodology (RSM) was applied to determine the impact of catalyst dosage, pH, and contact time on the MC-LR removal. High-performance liquid chromatography was performed to measure the MC-LR concentration. Based on the results, independent parameters, including contact time, catalyst dosage, and pH, significantly affected the MC-LR removal (P < 0.05). In other words, increasing the contact time, catalyst dosage, and acidic pH had positive effects on MC-LR removal. Among these variables, the catalyst dosage, with the mean square and F-value of 1041.37 and 162.84, respectively, had the greatest effect on the MC-LR removal efficiency. Apart from the interaction between the catalyst dosage and contact time, the interaction effects of other parameters were not significant. Also, the maximum MC-LR removal efficiency was 99.88% under optimal conditions (contact time = 120 min, catalyst dosage = 1 g/L, and pH = 5). According to the results, the B/T/N-Z nanocomposite, as a novel and effective photocatalyst could be used to degrade MC-LR from polluted water.


Assuntos
Luz , Toxinas Marinhas/química , Microcistinas/química , Nanocompostos/efeitos da radiação , Titânio/efeitos da radiação , Vanadatos/efeitos da radiação , Poluentes Químicos da Água/química , Ítrio/efeitos da radiação , Zeolitas/efeitos da radiação , Bismuto/química , Catálise , Nanocompostos/química , Processos Fotoquímicos , Titânio/química , Vanadatos/química , Purificação da Água/métodos , Ítrio/química , Zeolitas/química
7.
ACS Appl Mater Interfaces ; 13(2): 2327-2335, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33401893

RESUMO

This study presents a controlled synthesis of NaYbF4@NaYF4 core-shell upconversion nanoparticles using the hot-injection technique. NaYF4 shells with tunable morphologies including long-rod, short-rod, and quasi-sphere are grown on identical NaYbF4 core nanoparticles by controlled injection of acetate or trifluoroacetate precursors. Mechanistic investigations reveal that anisotropic interfacial strain accounts for the preferential growth of shell layers along the c-axis. However, the strain effect can be offset by the fast injection of shell precursors, leading to nearly isotropic growth of NaYF4 shells over the NaYbF4 core nanoparticles. The core-shell nanoparticles are further modified with DNA molecules and incubated with adenocarcinomic human alveolar basal epithelial cells. Based on a combination of characterizations by flow cytometry and confocal microscopy, favorable cellular uptake and DNA delivery are observed for the quasi-sphere nanoparticles, owing to the high dispersibility and easy membrane wrapping. The method described here could be extended to synthesize other types of functional nanostructures for the study of morphology-dependent properties.


Assuntos
Portadores de Fármacos/química , Fluoretos/química , Nanopartículas/química , Itérbio/química , Ítrio/química , Células A549 , DNA/administração & dosagem , DNA/farmacocinética , Portadores de Fármacos/metabolismo , Fluoretos/metabolismo , Técnicas de Transferência de Genes , Humanos , Nanopartículas/metabolismo , Nanopartículas/ultraestrutura , Nanotecnologia , Itérbio/metabolismo , Ítrio/metabolismo
8.
ACS Appl Mater Interfaces ; 13(2): 3481-3490, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33347289

RESUMO

Nanocrystals having single-band red emission under near-infrared (NIR) excitation through the upconversion process offer great advantages in terms of enhanced cellular imaging in in vitro and in vivo experiments in the biological window (600-900 nm), as a security ink, in photothermal therapy (PTT), in photodynamic therapy (PDT), and so forth but are challenging for materials scientists. In this work, we report for the first time the preparation of a super bright red emitter at 655 nm from monodispersed NaErF4:0.5%Tm@NaYF4:20%Yb nanocrystals (core@active shell). This phosphor exhibits 35 times stronger photoluminescence as compared to NaErF4:0.5%Tm@NaYF4 (core@inactive shell). Here, an Er3+-enriched host matrix works simultaneously as an activator and a sensitizer under NIR excitation. Upconversion red emission at 655 nm arises due to the electronic transition of Er3+ via the involvement of a three-photon absorption (expected to be a two-photon absorption), which has been confirmed via a power-dependent luminescence study. Tm3+ ions incorporated into the core with the active shell act as trapping centers, which promote the red band emission via the back-energy transfer process. Moreover, the active shell containing Yb3+ ions efficiently transfers the energy to the Er3+-enriched core, which suppresses the nonradiative channel rate, and Tm3+ ions act as trapping centers, which reduce the luminescence quenching via reduction of energy migration to the surface of the host lattice. Also, we have shown the potential applications of these nanocrystals: cellular imaging through downconversion and upconversion processes and security ink.


Assuntos
Érbio/química , Fluoretos/química , Substâncias Luminescentes/química , Nanopartículas/química , Itérbio/química , Ítrio/química , Células A549 , Transferência de Energia , Humanos , Luminescência , Medições Luminescentes , Células MCF-7 , Imagem Óptica
9.
Artigo em Inglês | MEDLINE | ID: mdl-33151184

RESUMO

This investigation was designed to evaluate the reestablishment of bone-to-implant contact on infected dental implant surfaces following decontamination with an erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser and reconstructive therapy. Three patients presenting with at least one failing implant each were enrolled and consented to treatment with the Er,Cr:YSGG laser surface decontamination and reconstruction with a bone replacement allograft and a collagen membrane. The laser treatment was carried out at a setting of 1.5 W, air/water of 40%/50%, and pulse rate of 30 Hz. At 6 months, all three patients returned for the study. En bloc biopsy samples of four implants were obtained and analyzed. Two patients had excellent clinical outcomes, while one patient with two adjacent failing implants experienced an early implant exposure during the follow-up period. There was histologic evidence of new bone formation with two implant specimens and less bone gain with the others. Despite the small sample size, these were optimistic findings that suggested a positive role of Er,Cr:YSGG laser in debridement of a titanium implant surface to facilitate subsequent regenerative treatment. This investigation provides histologic evidence as well as encouraging clinical results that use of the Er,Cr:YSGG laser can be beneficial for treatment of peri-implantitis, but further long-term clinical studies are needed to investigate the treatment outcome obtained.


Assuntos
Implantes Dentários , Lasers de Estado Sólido , Implantes Dentários/efeitos adversos , Érbio , Humanos , Lasers de Estado Sólido/uso terapêutico , Titânio , Ítrio
10.
Niger J Clin Pract ; 23(9): 1188-1193, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32913155

RESUMO

Aims: The aim of this study was to investigate the antimicrobial effect of Erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser with and without NaOCl solution. A total of 81 extracted human mandibular premolar teeth were used. Materials and Methods: After root canal preparation and sterilization, the samples were inoculated with E. faecalis for 24 hours. The specimens were divided into 4 experimental groups. Group 1 (n = 25) was irradiated with 2 W laser, group 2 (n = 25) was irradiated with 0.75 W laser in combination with 2.5% NaOCl, group 3 (n = 25) was irrigated with 5% NaOCl and group 4 (n = 6) was not treated. Statistical analysis was performed by using Wilcoxon Signed Ranks, Mann-Whitney U and Kruskal-Wallis H tests. Results: The combination of 0.75 W laser with 2.5% NaOCl regime was found to be just as effective at inhibiting the growth of E. faecalis and sterilization of all root canals as 5% NaOCl irrigation (P > 0.001). The 2 W laser had significant bactericidal effect in infected root canals however it did not eradicate all bacteria. The SEM observations were in accordance with the microbiologic findings. Conclusions: Within the limitations of this laboratory study, NaOCl irrigation improved the antimicrobial effect of Er,Cr:YSGG laser irradiation. When the toxic effects of high percentage of NaOCl was considered, the combination of low-powered laser and low concentration of NaOCl can be used as an effective disinfection method in root canal treatment.


Assuntos
Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Cavidade Pulpar/microbiologia , Enterococcus faecalis/efeitos dos fármacos , Lasers de Estado Sólido/uso terapêutico , Irrigantes do Canal Radicular/farmacologia , Hipoclorito de Sódio/farmacologia , Cromo , Érbio , Gálio , Humanos , Preparo de Canal Radicular , Tratamento do Canal Radicular/métodos , Escândio , Ítrio
11.
PLoS One ; 15(8): e0235421, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32756552

RESUMO

We investigated rock varnish, a thin, manganese- and iron-rich, dark surface crust, on basaltic lava flows and petroglyphs in the Owens and Rose Valleys (California) by portable X-ray fluorescence (pXRF) and femtosecond laser-ablation inductively-coupled-plasma mass spectrometry (fs-LA-ICPMS). The major element composition of the varnish was consistent with a mixture of Mn-Fe oxyhydroxides and clay minerals. As expected, it contained elevated concentrations of elements that are typically enriched in rock varnish, e.g., Mn, Pb, Ba, Ce, and Co, but also showed unusually high enrichments in U, Cu, and Th. The rare earth and yttrium (REY) enrichment pattern revealed a very strong positive cerium (Ce) anomaly and distinct negative europium (Eu) and Y anomalies. The light rare earth elements (REE) were much more strongly enriched than the heavy REY. These enrichment patterns are consistent with a formation mechanism by leaching of Mn and trace elements from aeolian dust, reprecipitation of Mn and Fe as oxyhydroxides, and scavenging of trace elements by these oxyhydroxides. We inferred accumulation rates of Mn and Fe in the varnish from their areal densities measured by pXRF and the known ages of some of the lava flow surfaces. The areal densities of Mn and Fe, as well as their accumulation rates, were comparable to our previous results from the desert of Saudi Arabia. There was a moderate dependence of the Mn areal density on the inclination of the rock surfaces, but no relationship to its cardinal orientation. We attempted to use the degree of varnish regrowth on the rock art surfaces as an estimate of their age. While an absolute dating of the petroglyphs was not possible because of the lack of suitable calibration surfaces and a considerable amount of variability, the measured degree of varnish regrowth on the various petroglyphs was consistent with chronologies based on archeological and other archaeometric techniques. In particular, our results suggest that rock art creation in the study area continued over an extended period of time, possibly starting around the Pleistocene/Holocene transition and extending into the last few centuries.


Assuntos
Argila/química , Hidróxidos/análise , Ferro/análise , Manganês/análise , California , Meio Ambiente , Monitoramento Ambiental , Espectrometria de Massas , Metais Terras Raras/análise , Espectrometria por Raios X , Propriedades de Superfície , Erupções Vulcânicas , Ítrio/análise
12.
Life Sci ; 259: 118287, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32814066

RESUMO

Alzheimer's disease (AD) is a fatal neurodegenerative disease that requires immediate attention. Oxidative stress that leads to the generation of reactive oxygen species is a contributing factor to the disease progression by promoting synthesis and deposition of amyloid-ß, the main hallmark protein in AD. It has been previously demonstrated that nanoyttria possesses antioxidant properties and can alleviate cellular oxidative injury in various toxicity and disease models. This review proposed that nanoyttria could be used for the treatment of AD. In this paper, the evidence on the antioxidant potential of nanoyttria is presented and its prospects on AD therapy are discussed.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Depuradores de Radicais Livres/farmacologia , Nanopartículas/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Ítrio/uso terapêutico , Doença de Alzheimer/metabolismo , Animais , Humanos , Ratos , Ítrio/administração & dosagem
13.
Int J Nanomedicine ; 15: 5061-5072, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764936

RESUMO

Purpose: Zirconia is one of the most promising implant materials due to its favorable physical, mechanical and biological properties. However, until now, we know little about the mechanism of osseointegration on zirconia. The purpose of this study is to evaluate the effect of Syndecan (Sdc) on osteoblastic cell (MC3T3-E1) adhesion and proliferation onto zirconia materials. Materials and Methods: The mirror-polished disks 15 mm in diameter and 1.5 mm in thick of commercial pure titanium (CpTi), 3mol% yttria-stabilized tetragonal zirconia polycrystalline (3Y-TZP) and nano-zirconia (NanoZr) are used in this study. MC3T3-E1 cells were seeded onto specimen surfaces and subjected to RNA interference (RNAi) for Syndecan-1, Syndecan-2, Syndecan-3, and Syndecan-4. At 48h post-transfection, the cell morphology, actin cytoskeleton, and focal adhesion were observed using scanning electron microscopy or laser scanning confocal fluorescence microscopy. At 24h and 48h post-transfection, cell counting kit-8 (CCK-8) assay was used to investigate cell proliferation. Results: The cell morphology of MC3T3-E1 cells on CpTi, 3Y-TZP, and NanoZr changed into abnormal shape after gene silencing of Syndecan. Among the Syndecan family, Sdc-2 is responsible for NanoZr-specific morphology regulation, via maintenance of cytoskeletal conformation without affecting cellular attachment. According to CCK-8 assay, Sdc-2 affects the osteoblastic cell proliferation onto NanoZr. Conclusion: Within the limitation of this study, we suggest that Syndecan affects osteoblastic cell adhesion on CpTi, 3Y-TZP, and NanoZr. Sdc-2 might be an important heparin-sensitive cell membrane regulator in osteoblastic cell adhesion, specifically on NanoZr, through the organization of actin cytoskeleton and affects osteoblastic cell proliferation.


Assuntos
Osseointegração/fisiologia , Osteoblastos/citologia , Osteoblastos/fisiologia , Sindecanas/metabolismo , Citoesqueleto de Actina/efeitos dos fármacos , Animais , Adesão Celular/fisiologia , Membrana Celular/efeitos dos fármacos , Proliferação de Células/fisiologia , Células Cultivadas , Camundongos , Microscopia Eletrônica de Varredura , Osseointegração/genética , Propriedades de Superfície , Sindecana-2/genética , Sindecana-2/metabolismo , Sindecanas/genética , Titânio/química , Ítrio/química , Zircônio/química
14.
J Adhes Dent ; 22(4): 373-382, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32666063

RESUMO

PURPOSE: To determine and compare the effects of tribochemical silica coating and alumina-particle air abrasion on 3 mol% and 5 mol% yttria-stabilized tetragonal zirconia polycrystals (Y-TZP). MATERIALS AND METHODS: Two different 3Y-TZP samples (Lava Plus, 3M Oral Care; Ceramill Zolid, Amann Girrbach) and one 5Y-TZP sample (Katana Zirconia UTML, Kuraray Noritake) were prepared and treated with alumina-particle air abrasion and a 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP)-containing self-adhesive composite cement or with tribochemical silica coating followed by silanization (n = 30). Resin columns were cemented onto the treated ceramic surfaces to form specimens. After 24-h water storage or aging with 10,000 thermocycles plus 60-day water storage, shear bond strength (SBS) testing was conducted. Surface roughness, surface Vickers hardness, and crystallographic phase analyses were also performed. RESULTS: The SBS of tribochemically silica-coated 5Y-TZP before and after aging were 13.8 ± 1.4 and 13.2 ± 1.5 MPa, resp., for Lava Plus (3Y-TZP) 14.4 ± 1.4 and 13.9 ± 1.6 MPa, respectively, and for Ceramill Zolid (3Y-TZP) 14.8 ± 1.1 and 13.9 ± 1.5 MPa, respectively. There was no statistical difference between tribochemical silica coating and alumina air abrasion treatments (p = 0.21) on the bonding performance (SBS) of the 3Y-TZPs and 5Y-TZP (p = 0.25) before and after aging (p = 0.50). After alumina air abrasion, 5Y-TZP showed higher surface roughness (Ra = 1.7 ± 0.1) than did the 3Y-TZPs (Ra = 1.2 ± 0.1 for Lava Plus; Ra = 1.2 ± 0.1 for Ceramill Zolid), while the Vickers hardness was similar among the three materials (p = 0.70). Monoclinic zirconia was not detected in 5Y-TZP irrespective of treatment, with the zirconia being mainly cubic phase. However, the 3Y-TZPs were mainly tetragonal phase with some monoclinic zirconia; the latter increased after being alumina-particle air abraded. CONCLUSION: The bond strength to 5Y-TZP is similar to those of the 3Y-TZPs under the same bonding strategies. Durable bonding can be achieved both by alumina air abrasion combined with a 10-MDP-containing self-adhesive composite cement and by tribochemical silica coating followed by silanization for both the 3Y-TZPs and 5Y-TZP.


Assuntos
Óxido de Alumínio , Colagem Dentária , Abrasão Dental por Ar , Dureza , Teste de Materiais , Cimentos de Resina , Dióxido de Silício , Propriedades de Superfície , Ítrio , Zircônio
15.
Ecotoxicol Environ Saf ; 203: 110951, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32678752

RESUMO

The growing use of rare-earth doped upconversion nanoparticles (UCNPs) has caused increasing concern about their biosafety. Here, to understand the toxicity of UCNPs and their mechanism in HepG2 cells, we systematically study the cytotoxicity, uptake and elimination behaviors of three types of UCNPs combined multiple cytotoxicity evaluation means with inductively coupled plasma mass spectrometry (ICP-MS) detection. Sodium yttrium fluoride, doped with 18% (molar ratio) ytterbium and 2% erbium (NaYF4: Yb3+, Er3+) was selected as the model UCNPs with two sizes (35 and 55 nm), and the poly(acrylic acid) and polyethylenimine were selected as the representatives of negative and positive surface coating of UCNPs, respectively. UCNPs were found to induce cytotoxicity in time- and dose-dependent manners, which might be mediated by reactive oxygen species generation and oxidative stress. Apoptosis, inflammation, and metabolic process were enhanced after cells exposed to 200 mg/L UCNPs for 48 h. Increase in the protein levels of cleaved caspased-9, cleaved caspase-3 and Bax and decrease in the anti-apoptotic protein, Bcl-2 suggested that the mitochondria mediated pathway was involved in UCNP-induced apoptosis. With the aid of ICP-MS, it demonstrated that the cytotoxicity was associated with internalized amount of UCNPs, which largely relied on their surface properties rather than size in the tested range. By comparing UCNPs with Y3+ ions, it demonstrated that NPs properties played a nonnegligible role in the cytotoxicity of UCNPs. These findings provide new insights for fundamental understanding of cytotoxicity of UCNPs and may contribute to more rational use of these materials in the future.


Assuntos
Endocitose/efeitos dos fármacos , Érbio/toxicidade , Fluoretos/toxicidade , Nanopartículas/toxicidade , Itérbio/toxicidade , Ítrio/toxicidade , Apoptose/efeitos dos fármacos , Técnicas de Cultura de Células , Sobrevivência Celular , Érbio/química , Érbio/metabolismo , Fluoretos/química , Fluoretos/metabolismo , Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Nanopartículas/química , Nanopartículas/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Tamanho da Partícula , Propriedades de Superfície , Itérbio/química , Itérbio/metabolismo , Ítrio/química , Ítrio/metabolismo
16.
PLoS One ; 15(6): e0234524, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32579584

RESUMO

The purpose of this study was to evaluate the adherence of streptococci to disks of titanium (commercially pure titanium: CpTi) and zirconia (tetragonal zirconia polycrystals: TZP). CpTi and yttria-stabilized TZP disks with a mirror-polished surface were used as specimens. The arithmetic mean surface roughness (Ra and Sa) and the surface wettability of the experimental specimens were measured. For analyzing the outermost layer of the experimental specimens, X-ray photoelectron spectroscopy (XPS) analysis was performed. Streptococcus sanguinis, S. gordonii, S. oralis, and S. mutans were used as streptococcal bacterial strains. These bacterial cultures were grown for 24 h on CpTi and TZP. The number of bacterial adhesions was estimated using an ATP-bioluminescent assay, and scanning electron microscope (SEM) observation of the adhered bacterial specimens was performed. No significant differences in surface roughness or wettability were found between CpTi and TZP. In XPS analyses, outermost layer of CpTi included Ti0 and Ti4+, and outermost layer of TZP included Zr4+. In the cell adhesion assay, the adherences of S. sanguinis, S. gordonii, and S. oralis to TZP were significantly lower than those to CpTi (p < 0.05); however, significant difference was not observed for S. mutans among the specimens. The adherence to CpTi and TZP of S. mutans was significantly lower than that of S. sanguinis, S. gordonii, and S. oralis. These results were confirmed by SEM. S. sanguinis, S. gordonii, and S. oralis adhered less to TZP than to CpTi, but the adherence of S. mutans was similar to both surfaces. S. mutans was less adherent compare with the other streptococci tested in those specimens.


Assuntos
Aderência Bacteriana/efeitos dos fármacos , Streptococcus sanguis/efeitos dos fármacos , Titânio/química , Zircônio/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Espectroscopia Fotoeletrônica , Streptococcus sanguis/química , Streptococcus sanguis/ultraestrutura , Propriedades de Superfície/efeitos dos fármacos , Ítrio/química
17.
Dent Mater ; 36(7): 959-972, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32493658

RESUMO

OBJECTIVE: To evaluate the performance of zirconia ceramics sintered in a speed sintering induction furnace by comprehensive understanding of their optical and mechanical properties, microstructure, phase composition and aging stability, in comparison to ceramics sintered in a conventional furnace. METHODS: Speed sintered (SS) Katana STMLSS (Kuraray Noritake) (total thermal cycle/sintering time/dwell temperature: 30min/16min/1560°C) and CEREC Zirconia (CEREC ZrSS) (Dentsply Sirona) (15min/2min/1578°C) were compared to conventionally sintered (CS) Katana STMLCS (6.8h/2h/1550°C) and inCoris TZICS (4h/2h/1510°C). The translucency parameter (TP) and contrast ratio (CR) were measured with a spectrophotometer. The chemical composition of the materials was determined by XRF and phase composition was characterized using XRD. Hydrothermal aging behavior was evaluated by measuring the tetragonal-to-monoclinic ZrO2 phase transformation after accelerated hydrothermal aging in steam at 134°C. The indentation fracture toughness, Vickers hardness and biaxial strength of the sintered ceramics were assessed. RESULTS: Speed and conventionally sintered zirconia revealed similar density, microstructure, average strength and hydrothermal aging stability. Both Katana STMLSS/CS 5Y-PSZ ceramics were characterized with a higher content of cubic phase (≈53wt%), which resulted in a higher amount of Y2O3 in the remaining tetragonal ZrO2 phases compared to the 3Y-TZP CEREC ZrSS and inCoris TZICS (8 and 20wt%, respectively). The sintering program did not affect the hydrothermal aging behavior of Katana STMLSS and CEREC ZrSS. TP of Katana STMLSS (TP≈32) was not affected by speed sintering, while the translucency of CEREC ZrSS (TP=14) was significantly reduced. Hardness, fracture toughness and Weibull characteristic strength of Katana STMLSS and CEREC ZrSS also reached the optimal level, but speed sintering substantially lowered their mechanical reliability. SIGNIFICANCE: Speed sintering of 3Y-TZP and 5Y-PSZ in a speed sintering induction oven appeared suitable for clinical applications. However, further studies should focus on improving of translucency and mechanical reliability of the speed-sintered zirconia ceramics.


Assuntos
Materiais Dentários , Ítrio , Cerâmica , Teste de Materiais , Reprodutibilidade dos Testes , Propriedades de Superfície , Zircônio
18.
PLoS One ; 15(6): e0233536, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32479553

RESUMO

BACKGROUND: Removal of cement-retained implant fixed restorations when needed, can be challenging. Conventional methods of crown removal are time consuming and costly for patients and practitioners. This research explored the use of two different types of pulsed erbium lasers as a non-invasive tool to retrieve cemented zirconia crowns from zirconia implant abutments. MATERIALS AND METHODS: Twenty identical zirconia crowns were cemented onto 20 identical zirconia prefabricated abutments using self-adhesive resin cement. The specimens were divided into two groups for laser assisted crown removal; G1 for erbium-doped yttrium aluminum garnet laser (Er:YAG), and G2 for erbium, chromium-doped yttrium, scandium, gallium and garnet (Er,Cr:YSGG). For the G1, after the first crown removal, the specimens were re-cemented and removed again using the Er:YAG laser. Times needed to remove the crowns were recorded and analyzed using ANOVA (α = 0.05). The surfaces of the crown and the abutment were further examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses. RESULTS: The average times of zirconia crown removal from zirconia abutments were 5 min 20 sec and 5 min 15 sec for the Er:YAG laser of first and second experiments (G1), and 5 min 55 sec for the Er,Cr:YSGG laser experiment (G2). No statistical differences were observed among the groups. SEM and EDS examinations of the materials showed no visual surface damaging or material alteration from the two pulsed erbium lasers. CONCLUSIONS: Both types of pulsed erbium lasers can be viable alternatives for retrieving a zirconia crown from a zirconia implant abutment. Despite operating at different wavelengths, the Er:YAG and Er,Cr:YSGG lasers, perform similarly in removing a zirconia crown from a zirconia implant abutment with similar parameters. There are no visual and elemental composition damages as a result of irradiation with pulsed erbium lasers.


Assuntos
Colagem Dentária/métodos , Prótese Dentária/métodos , Lasers de Estado Sólido/uso terapêutico , Cromo , Coroas , Érbio , Gálio , Humanos , Microscopia Eletrônica de Varredura/métodos , Cimentos de Resina , Coroa do Dente/fisiologia , Ítrio , Zircônio
19.
J Contemp Dent Pract ; 21(1): 11-16, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32381794

RESUMO

AIM: To compare the antimicrobial effects of two different irrigation solutions activated with erbium, chromium-doped yttrium, scandium, gallium and garnet (Er,Cr:YSGG) laser or an ultrasonic system and a photodynamic therapy (PDT) on Enterococcus faecalis (E. faecalis). MATERIALS AND METHODS: The root canals of 72 single-rooted human permanent incisors were prepared with ProTaper Universal rotary instruments and incubated with E. faecalis (ATCC 29212) for 4 weeks. Then the teeth were randomly divided into seven experimental groups with 10 specimens for canal disinfection procedures. Group I, standard needle irrigation (SNI) with 2.5% sodium hypochlorite (NaOCl); group II, SNI with 2% chlorhexidine gluconate (CHX); group III, laser-activated irrigation (LAI) by Er,Cr:YSGG of NaOCl; group IV, LAI of CHX; and group V, passive ultrasonic irrigation (PUI) of NaOCl; group VI, PUI of CHX; group VII, PDT. The remaining two teeth were used as the control group. After the disinfection procedures were completed, the root canals were filled with phosphate-buffered saline and bacterial samples were taken with sterile paper cones. The cultivation was performed on Mueller-Hinton agar (MHA) plates. The live bacteria were calculated by counting the colonies on these plaques. The statistical analysis was performed using Kruskal-Wallis H test and Miller's multiple comparison technique. RESULTS: Both LAI and PUI of NaOCl and PUI of CHX were more successful than the PDT on root canal disinfection (p < 0.05). CONCLUSION: Within the limitation of the present study, the activation of NaOCl solution by Er,Cr:YSGG laser or an ultrasonic system can be useful in the elimination of the E. faecalis from the canal. The PUI of CHX also has similar results. Photodynamic therapy showed a lower performance compared to these methods. CLINICAL SIGNIFICANCE: The activation of the sodium hypochlorite with Er,Cr:YSGG laser or PUI may be useful for removal of the E. faecalis biofilm layer in the root canal.


Assuntos
Gálio , Fotoquimioterapia , Cromo , Cavidade Pulpar , Enterococcus faecalis , Érbio , Humanos , Irrigantes do Canal Radicular , Escândio , Ultrassom , Ítrio
20.
Sci Total Environ ; 732: 139276, 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32438156

RESUMO

The wide applications of rare earth oxide nanoparticles (REO NPs) in various fields and their subsequent release into the environment have attracted the research of their effects on organisms. In this study, the toxicity of yttrium oxide (Y2O3) NPs to tobacco BY-2 cells was evaluated and the importance of phosphate in the medium on the toxicity of Y2O3 NPs was revealed. 50 mg L-1 Y2O3 NPs induced 52.4% cellular growth inhibition after 24-h exposure. Phosphate inhibited the release of Y3+ from Y2O3 NPs from 6.00 to 0.04 mg L-1 at 24 h, thus reduced the toxicity of Y2O3 NPs. The surface charge of Y2O3 NPs changed from 24.0 mV (in deionized water) to -7.6 mV (in phosphate solution), which induced the aggregation of Y2O3 NPs. The change of surface properties reduced the direct nanotoxicity of Y2O3 NPs. High-resolution transmission electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, and X-ray diffraction results demonstrated that phosphate transformed the surface of Y2O3 NPs to amorphous YPO4. This surface transformation decreased phosphate concentration in the medium. The dialysis membrane encapsulation experiment further identified the contribution percentage of direct nanotoxicity and indirect toxicity (i.e., phosphate depletion) of Y2O3 NPs to tobacco BY-2 cells in the presence of phosphate to be 68.3% and 31.7%, respectively. This study highlights the significant role of phosphate in altering the environmental behavior and toxicity of REO NPs.


Assuntos
Nanopartículas , Fosfatos , Diálise Renal , Tabaco , Difração de Raios X , Ítrio
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