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1.
Talanta ; 233: 122530, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215033

RESUMO

Herein, a matrix-free approach is presented for comprehensive environmental and forensic analysis of dyes and nonsteroidal anti-inflammatory drugs (NSAIDs) using Au-TiO2 nanohybrids coupled with surface-assisted pulsed laser desorption ionization-mass spectrometry (SALDI-MS). The Au-TiO2 nanohybrids was prepared and characterized using inductively coupled plasma-optical emission spectrometry (ICP-OES), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), surface area measurements, ultraviolet-visible (UV-vis) spectroscopy, transmission electron microscopy (TEM), and scanning electron microscopy-energy dispersive spectrometry (SEM-EDS). Initially, the optimal Au content was assessed using the survival yield (SY) method, confirming that 7.5% Au content on the TiO2 surface offered the highest ionization efficiency. Subsequently, environmental analyses of dyes and NSAIDs in water samples were performed, and sensitive detection of all analytes was achieved with limits of detection (LODs) ranging from 10.0 ng mL-1 to 10.0 fg mL-1 and good spot-to-spot reproducibility. Additionally, the effect of potential contaminants commonly found in environmental samples, such as salts, surfactants and pesticides was also considered. Despite signal intensity reduction at high concentrations of some salts, the target analytes were detected, while the presence of surfactants and pesticides did not cause significant signal intensity reduction. Additionally, dyed and undyed Tetoron fibers and the effect of adhesive tape were evaluated. Direct analysis of the dyed Tetoron fibers on the target plate, using the nanohybrids, enabled higher detection sensitivity of the dyes, in addition to adducts of polystyrene and cellulose, the main components of the fiber. Finally, NSAIDs in oral fluid were analyzed and sensitive detection of the analytes was observed using the nanohybrids with LODs and LOQs in the range of 0.1-10 ng mL-1 and 1-20 ng mL-1, respectively. The trueness of the exact mass was in the range of 0.64-6.2 ppm while the recovery of the spiked samples was in the range of 82.90-107.54%% indicating the efficiency of the Au-TiO2 nanohybrids as SALDI substrate. Thus, the Au-TiO2 nanohybrids hold considerable promise in terms of sensitivity, reproducibility, and LOD, and may significantly contribute to environmental and forensic identification.


Assuntos
Anti-Inflamatórios não Esteroides , Corantes , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Titânio
2.
Talanta ; 233: 122551, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215054

RESUMO

In this work, a simple and highly sensitive photoelectrochemical (PEC) aptasensor has been developed for detecting PCB72 based on TiO2 nanotubes (NTs) decorated with BiVO4 nanoparticles (NPs). The BiVO4 NPs-TiO2 NTs composites prepared through a simple hydrothermal method exhibit good visible-light adsorption ability, high PEC response and perfect photo-excited stability. The synthesized composites were explored as the photoactive sensing materials for development of a PEC sensing platform for the first time. Here, Au nanoparticles (NPs) were first deposited the composites, and the anti-PCB72 aptamer molecules were immobilized on the Au NPs-deposited BiVO4 NPs-TiO2 NTs. The developed PEC aptasensor exhibits high sensitivity and specificity for PCB72 with a wide linear range from 1 ng/L to 500 ng/L and a low detection limit of 0.23 ng/L. The application of the aptasensor was evaluated by determining PCB 72 in the environment water samples. Thus, a simple and efficient PEC sensing platform was established for detecting the content of PCBs in the environment.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanopartículas Metálicas , Nanotubos , Técnicas Eletroquímicas , Ouro , Limite de Detecção , Titânio
3.
Talanta ; 233: 122587, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215077

RESUMO

Phosphopeptides were of great significance in disease diagnosis and monitoring its dynamic changes. In this article, we proposed a more efficient method to synthesize a kind of bimetallic mesoporous silica nanomaterials (Fe3O4@mSiO2-PO3-Ti4+/Zr4+) and applied it to the analysis of phosphopeptides in human saliva samples based on IMAC technology. The chelation group was introduced into mesopores at the same time as the formation of mesoporous silica which significantly reduced the synthesis procedure and improved the synthesis efficiency. The as-prepared materials showed great sensitivity, selectivity and size-exclusion performance for phosphopeptides in standard ß-casein digests. More importantly, the materials identified 85 phosphopeptides in disease saliva samples which provided a candidate choice in future clinical examination.


Assuntos
Fosfopeptídeos , Saliva , Humanos , Íons , Dióxido de Silício , Titânio
4.
Talanta ; 233: 122494, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215112

RESUMO

Titanium dioxide nanoparticles (TiO2 NPs) are widely used in industry as a white pigment (paints, paper industry and toothpastes), photocatalysts (environmental decontamination and photovoltaic cells), inorganic UV filter (sunscreens and personal care products) and as a food additive (E171) and antimicrobial food packaging material. Silver nanoparticles (Ag NPs) are used in photonics, microelectronics, catalysis and medicine due to their catalytic activity, magnetic and optical polarizability, electrical and thermal conductivities and enhanced Raman scattering. They also have antibacterial, antifungal and antiviral activities, as well as anti-inflammatory potential. The huge increase in the use of nano-based products, mainly metallic NPs, implies the presence of nanomaterials in the environment, and hence, the unintentional human ingestion through water or foods (gastrointestinal tract is the main pathway of NPs intake in humans). The presence of TiO2 NPs and Ag NPs in seafood samples was firstly established using an ultrasound assisted enzymatic hydrolysis procedure and sp-ICP-MS analysis. Several clams, cockles, mussels, razor clams, oysters and variegated scallops, which contain TiO2 NPs and Ag NPs, were subjected to an in vitro digestion process simulating human gastrointestinal digestion in the stomach and in the small and large intestine to determine the bioaccessibility of these NPs. Caco-2 cells were selected as model of human intestinal epithelium for transport studies because of the development of membrane transporters that are responsible for the uptake of chemicals. Parameters as transepithelial electrical resistance (TEER) and permeability of Lucifer Yellow were studied for establishing cell monolayer integrity. TiO2 NPs and Ag NPs transport as well as total Ti and Ag concentrations passing through the gastrointestinal epithelial barrier model (0-2 h) were assessed by sp-ICP-MS and ICP-MS in several molluscs.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Células CACO-2 , Trato Gastrointestinal , Humanos , Alimentos Marinhos , Prata , Titânio
5.
Talanta ; 233: 122497, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215115

RESUMO

Highly specific capture of phosphopeptides, especially multi-phosphopeptides, from complex biological samples is critical for comprehensive phosphoproteomic analysis, but it still poses great challenges due to the lack of affinity material with ideal enrichment efficiency. Here, two-dimensional (2D) covalent organic framework (COFs) nanosheets was applied for selective separation of phosphopeptides for the first time. Particularly, by incorporating guanidinium units, the 2D guanidinium-based COF nanosheets (denoted as TpTGCl CONs) exhibited controllable and specific enrichment performance towards global/multi-phosphopeptides. TpTGCl CONs was easy to prepare and showed large surface area, low steric hindrance, abundant accessible interaction sites and high chemical stability. Taking these merits together, TpTGCl CONs exhibited excellent efficiency for phosphopeptide enrichment, such as low detection limits (0.05 fmol µL-1 for global phosphopeptides and 0.1 fmol µL-1 for multi-phosphopeptides), high selectivity (1:5000 of molar ratios of ß-casein/BSA for both global and multi-phosphopeptides), high adsorption capacity (100 mg g-1 for global phosphopeptides and 50 mg g-1 for multi-phosphopeptides). Furthermore, TpTGCl CONs could be reused due to the high chemical stability. In addition, TpTGCl CONs were successfully applied to controllable and specific capture of endogenous global/multi-phosphopeptides from human serum and human saliva, indicating its good potential in rapid and sensitive detection of biomarkers from biological fluid. Finally, rat liver protein digest was used to confirm the high specificity of TpTGCl CONs towards multi-phosphopeptides and demonstrated its potential as an ideal enrichment probe for comprehensive phosphoproteomic analysis.


Assuntos
Estruturas Metalorgânicas , Fosfopeptídeos , Adsorção , Cromatografia de Afinidade , Guanidina , Titânio
6.
Mater Sci Eng C Mater Biol Appl ; 127: 112259, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34225844

RESUMO

This study is aimed to evaluate the influence of mechanical surface treatment on the degradation response, cell survival, adhesion, and proliferation of a TiMg composite material. Two sets of the TiMg samples with different surface characteristics were studied: i) as-machined samples (TiMg-T) and ii) samples with a mechanically modified surface (TiMg-P). Surface roughness was determined using a confocal microscope. Degradation rates (DR) were evaluated in artificial Plasma, HBSS, and NaCl 0.9%. The cell viability was evaluated using an MTT assay. The initial cell adhesion and spreading were investigated using the direct contact assay. An xCELLigence system was employed to provide real-time cell proliferation. The focal adhesion and cell morphological changes were also examined. The DR of TiMg-P decreased by ⁓5 times compared with that of TiMg-T. Surface of the TiMg-P specimens after 72 h exposure to either HBSS or Plasma was passivated by a layer enriched with bioactive Ca/P species. The cell viability of L929 and Saos-2 after 72 h incubation for TiMg-P was 94.6% and 94.8% compared with 73.8% and 74.3% obtained for TiMg-T, respectively. The direct contact assay showed that the initial adhesion and spreading of the L929 cells incubated with TiMg-P was more pronounced compared with that of TiMg-T. The proliferation rate of Saos-2 cells incubated with TiMg-P was higher when compared with that of TiMg-T, and was almost comparable to that of the DMEM-blank between the 24 and 72 h interval. TiMg-P had a pronounced difference in the number and area of Focal Adhesions (FA) compared with that of TiMg-T. The morphology of cells incubated with TiMg-P was not altered. The results confirmed that the smooth and less strained surface of the TiMg-P samples effectively improved the in-vitro degradation response, cell survival, adhesion, and proliferation.


Assuntos
Titânio , Adesão Celular , Proliferação de Células , Sobrevivência Celular , Propriedades de Superfície
7.
Mater Sci Eng C Mater Biol Appl ; 127: 112191, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34225847

RESUMO

The zirconia implants have a wide range of clinical applications, however, the biological inertness and lack of osteoinductive properties limit these applications. Strontium possesses superior biocompatibility and excellent osteogenic properties. To take advantage of these, the strontium titanate-coated zirconia implants were prepared in this study by sandblasting, acid etching, and magnetron sputtering, followed by the analysis of the biological behavior. Briefly, the zirconia sheets were polished and subjected to sandblasting and acid etching. Subsequently, a nano­strontium titanate coating was developed on the sheets by magnetron sputtering. The specimens were characterized by scanning electron microscopy (SEM), water contact angle measurement (WCA) and EDS mapping, which confirmed the physical alternation and successful deposition of the strontium titanate coating. The in vitro experiments indicated that the majority of the filopodia and actin fibers of the MC3T3-E1 cells on SA-ZrO2/Sr possessed an optimal osteogenic property to promote the osteogenic differentiation. Moreover, the RT-PCR results revealed that SA-ZrO2/Sr significantly up-regulated the gene expression of Runx2, COL-1, ALP, OPG, OPN and OCN. Further, the in vivo evaluation confirmed that the SA-ZrO2/Sr implants promoted the bone-implant osseointegration to the greatest extent as compared to SA-ZrO2 and ZrO2 implant. Overall, the SA-ZrO2/Sr system was confirmed to be a promising implant, thus, providing new pathways for an effective implant design.


Assuntos
Osteogênese , Estrôncio , Osseointegração , Estrôncio/farmacologia , Propriedades de Superfície , Titânio/farmacologia , Zircônio
8.
Mater Sci Eng C Mater Biol Appl ; 127: 112247, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34225886

RESUMO

The osteogenic activity of medical metal can be improved by lowering its surface stiffness and elastic modulus. However, it is very difficult to directly reduce the elastic modulus of medical metal surfaces. In this paper, with selected parameters, the titanium surface was treated via femtosecond laser irradiation. Micro indentation revealed that the femtosecond laser ablation can effectively reduce the surface Young's modulus and Vickers hardness of titanium. Besides, In order to explain the mechanical properties of degradation of titanium surface, Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) was used to simulate the process of laser ablation process of titanium surface, and it was found that after the ablation of titanium surface, voids were produced in the subsurface layer. The simulation showed that the voids are formed by the cavitation of metastable liquid induced by high tensile stress and high temperature during femtosecond laser irradiation. Subsurface voids with a thickness of about 40 nm were observed under the oxide layer in the experiment. Cell experiments showed that the surface with low Young's modulus was more conducive to cell proliferation and osteogenic differentiation.


Assuntos
Nanoporos , Osteogênese , Lasers , Próteses e Implantes , Propriedades de Superfície , Titânio
9.
Mater Sci Eng C Mater Biol Appl ; 127: 112250, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34225889

RESUMO

Customized spinal implants fabricated by additive manufacturing have been increasingly used clinically to restore the physiological functions. However, the mechanisms and methods about the design for the spinal implants are not clear, especially for the reconstruction of multi-segment vertebral. This study aims to develop a novel multi-objective optimization methodology based on various normal spinal activities, to design the artificial vertebral implant (AVI) with lightweight, high-strength and high-stability. The biomechanical performance for two types of AVI was analyzed and compared under different loading conditions by finite element method. These implants were manufactured via selective laser melting technology and evaluated via compressive testing. Results showed the maximum Mises stress of the optimized implant under various load cases were about 41.5% of that of the trussed implant, and below fatigue strength of 3D printed titanium materials. The optimized implant was about 2 times to trussed implant in term of the maximum compression load and compression stiffness to per unit mass, which indicated the optimized implant can meet the safety requirement. Finally, the optimized implant has been used in clinical practice and good short-term clinical outcomes were achieved. Therefore, the novel developed method provides a favorable guarantee for the design of 3D printed multi-segment artificial vertebral implants.


Assuntos
Próteses e Implantes , Titânio , Fenômenos Biomecânicos , Análise de Elementos Finitos , Lasers , Impressão Tridimensional , Estresse Mecânico
10.
Mater Sci Eng C Mater Biol Appl ; 127: 112251, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34225890

RESUMO

A variety of novel biomaterials are emerging as alternatives to conventional metals and alloys, for use in spinal implants. These promise potential advantages with respect to e.g. elastic modulus compatibility with the host bone, improved radiological imaging or enhanced cellular response to facilitate osseointegration. However, to date there is scarce comparative data on the biological response to many of these biomaterials that would give insights into the relative level of bone formation, resorption inhibition and inflammation. Thus, in this study, we aimed to evaluate and compare the in vitro biological response to standard discs of four alternative biomaterials: polyether ether ketone (PEEK), zirconia toughened alumina (ZTA), silicon nitride (SN) and surface-textured silicon nitride (ST-SN), and the reference titanium alloy Ti6Al4V (TI). Material-specific characteristics of these biomaterials were evaluated, such as surface roughness, wettability, protein adsorption (BSA) and apatite forming capacity in simulated body fluid. The activity of pre-osteoblasts seeded on the discs was characterized, by measuring viability, proliferation, attachment and morphology. Then, the osteogenic differentiation of pre-osteoblasts was compared in vitro from early to late stage by Alizarin Red S staining and real-time PCR analysis. Finally, osteoclast activity and inflammatory response were assessed by real-time PCR analysis. Compared to TI, all other materials generally demonstrated a lower osteoclastic activity and inflammatory response. ZTA and SN showed generally an enhanced osteogenic differentiation and actin length. Overall, we could show that SN and ST-SN showed a higher osteogenic effect than the other reference groups, an inhibitive effect against bone resorption and low inflammation, and the results indicate that silicon nitride has a promising potential to be developed further for spinal implants that require enhanced osseointegration.


Assuntos
Materiais Biocompatíveis , Osteogênese , Materiais Biocompatíveis/farmacologia , Teste de Materiais , Osseointegração , Osteoblastos , Próteses e Implantes , Propriedades de Superfície , Titânio
11.
Bone Joint J ; 103-B(7 Supple B): 73-77, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34192909

RESUMO

AIMS: Dual mobility (DM) implants have been shown to reduce the dislocation rate after total hip arthroplasty (THA), but there remain concerns about the use of cobalt chrome liners inserted into titanium shells. The aim of this study was to assess the clinical outcomes, metal ion levels, and periprosthetic femoral bone mineral density (BMD) at mid-term follow-up in young, active patients receiving a modular DM THA. METHODS: This was a prospective study involving patients aged < 65 years, with a BMI of < 35 kg/m2, and University of California, Los Angeles activity score of > 6 who underwent primary THA with a modular cobalt chrome acetabular liner, highly cross-linked polyethylene mobile bearing, and a cementless titanium femoral stem. Patient-reported outcome measures, whole blood metal ion levels (µg/l), and periprosthetic femoral BMD were measured at baseline and at one, two, and five years postoperatively. The results two years postoperatively for this cohort have been previously reported. RESULTS: A total of 43 patients were enrolled. At minimum follow-up of five years, 23 (53.4%) returned for clinical and radiological review, 25 (58.1%) had metal ion analysis performed, 19 (44.2%) underwent dual energy x-ray absorptiometry scans, and 25 (58%) completed a pain-drawing questionnaire. The mean modified Harris Hip Scores improved significantly from 54.8 (SD 19) preoperatively to 93.08 (SD 10.5) five years postoperatively (p < 0.001). One patient was revised for aseptic acetabular loosening. The mean cobalt levels increased from 0.065 µg/l (SD 0.03) to 0.08 (SD 0.05) and the mean titanium levels increased from 0.35 (SD 0.13) to 0.78 (SD 0.29). The femoral BMD ratio decreased in Gruen Zone 1 (91.9%) at five years postoperatively compared with the baseline scores at six weeks potoperatively. The femoral BMD ratio was maintained in Gruen zones 2 to 7. CONCLUSION: The use of a modular DM component and a cementless, tapered femoral stem shows excellent mid-term survivorship with minimal concerns for corrosion and metal ion release in a cohort of young, active patients undergoing primary THA. Cite this article: Bone Joint J 2021;103-B(7 Supple B):73-77.


Assuntos
Artroplastia de Quadril/métodos , Prótese de Quadril , Desenho de Prótese , Adulto , Densidade Óssea , Ligas de Cromo , Feminino , Seguimentos , Humanos , Íons/sangue , Masculino , Pessoa de Meia-Idade , Polietileno , Estudos Prospectivos , Titânio
12.
Int J Mol Sci ; 22(12)2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34198700

RESUMO

Vacuum cathodic arc TiN coatings with overlaying TiO2 film were deposited on polished and surface roughened by electron beam modification (EBM) Ti6Al4V alloy. The substrate microtopography consisted of long grooves formed by the liner scan of the electron beam with appropriate frequencies (500 (AR500) and 850 (AR850) Hz). EBM transformed the α + ß Ti6Al4V mixed structure into a single α'-martensite phase. Тhe gradient TiN/TiO2 films deposited on mechanically polished (AR) and EBM (AR500 and AR850) alloys share the same surface chemistry and composition (almost stoichiometric TiN, anatase and rutile in different ratios) but exhibit different topographies (Sa equal to approximately 0.62, 1.73, and 1.08 µm, respectively) over areas of 50 × 50 µm. Although the nanohardness of the coatings on AR500 and AR850 alloy (approximately 10.45 and 9.02 GPa, respectively) was lower than that measured on the film deposited on AR alloy (about 13.05 GPa), the hybrid surface treatment offered improvement in critical adhesive loads, coefficient of friction, and wear-resistance of the surface. In phosphate buffer saline, all coated samples showed low corrosion potentials and passivation current densities, confirming their good corrosion protection. The coated EBM samples cultured with human osteoblast-like MG63 cells demonstrated increased cell attachment, viability, and bone mineralization activity especially for the AR500-coated alloy, compared to uncoated polished alloy. The results underline the synergetic effect between the sub-micron structure and composition of TiN/TiO2 coating and microarchitecture obtained by EBM.


Assuntos
Ligas/química , Materiais Biocompatíveis/química , Eletroquímica , Elétrons , Titânio/química , Calcificação Fisiológica/fisiologia , Adesão Celular , Linhagem Celular Tumoral , Sobrevivência Celular , Módulo de Elasticidade , Fricção , Dureza , Humanos , Microscopia de Força Atômica , Difração de Raios X
13.
Molecules ; 26(11)2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34205177

RESUMO

Fibrous Ti/Ce oxide photocatalysts were prepared for the first time by a biomimetic solution process using short flax fibers (flax straw processing waste) as a biotemplate. Titanium polyhydroxy complex solutions with 3% and 5% cerium were used as precursors. Flax fibers were impregnated in an autoclave under hydrothermal conditions. Ti/Ce oxides were obtained from the biotemplate by annealing at 600 °C. The photocatalytic activity of the Ti/Ce oxides was studied by the adsorption and decomposition of the dye rhodamine B under UV irradiation. The photocatalytic decomposition of the dye was 50% and 75% faster for Ti/Ce oxides with 3% and 5% Ce, respectively, than for the analogous undoped fibrous TiO2. The morphologies, textures, and structures of the photocatalysts were studied by scanning electron microscopy, low temperature N2 adsorption/desorption, UV-Vis spectroscopy, and X-ray and XPS analytical methods. It was shown that the introduction of Ce into the precursor solution increased the surface irregularity of the Ti/Ce oxide crystallites compared to pure TiO2. This effect scaled with the Ce concentration. Ce improved the UV light absorption of the material. The Ti/Ce oxides contained Ce4+/Ce3+ pairs that played an important role in redox processes and intensified the photocatalytic activity.


Assuntos
Cério/química , Linho/química , Rodaminas/análise , Titânio/química , Adsorção , Catálise , Relação Dose-Resposta a Droga , Microscopia Eletrônica de Varredura , Fotoquímica , Espectroscopia Fotoeletrônica
14.
J Contemp Dent Pract ; 22(3): 215-218, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34210917

RESUMO

AIM AND OBJECTIVE: The aim and objective of this study was to evaluate and compare the cutting efficacy of two different nickel titanium rotary instruments by a novel methodology: the operative torque (torque and time needed to progress toward the apex). MATERIALS AND METHODS: Ten fresh extracted upper first premolars with two canals were instrumented with a KaVo (Biberach, Germany) and a KaVo 1:1 handpiece at 300 rpm with maximum torque set at 2 N. One canal was instrumented with ProGlider NiTi rotary instruments (Dentsply Sirona Endodontics, Ballaigues, Switzerland), with tip size of 16.02, and the other one with EgdeGlidePath rotary instrument (EdgeEndo, Albuquerque, New Mexico). Mean instrumentation time, mean torque values, and maximum torque values were evaluated for each instrument. The significance level was set at p <0.05. RESULTS: EdgeGlidePath instruments reached the working length in significantly less time with a significantly smaller amount of torque when compared to ProGlider (p >0.05). No instruments exhibited flute deformation or underwent intracanal failure. CONCLUSIONS: Operative torque is related to the capability to cut dentin and progress toward the apex: the smaller the torque values, the higher the cutting ability (and safety). Operative torque is also dependent on debris removal and irrigation techniques. Nevertheless, both operative torque and instrumentation time are clinically relevant parameters for evaluating instruments' performance (i.e., cutting ability). CLINICAL SIGNIFICANCE: Operative torque during endodontic instrumentation helps understanding the overall performance in terms of both cutting efficiency and safety.


Assuntos
Níquel , Preparo de Canal Radicular , Ligas , Ligas Dentárias , Instrumentos Odontológicos , Cavidade Pulpar , Desenho de Equipamento , Alemanha , Titânio , Torque
15.
J Contemp Dent Pract ; 22(4): 349-352, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-34267001

RESUMO

AIM AND OBJECTIVE: The aim of this study was to evaluate the apical extrusion of debris during root canal preparation with the use of different Nickel-Titanium (Ni-Ti) file systems. MATERIALS AND METHODS: Totally 60 single-rooted human mandibular premolar teeth with fully formed roots were chosen for the study. The coronal access cavity and all other preparations were done with the use of an access cavity kit and then 60 samples were randomly separated into three investigational groups (n = 20); group I: self-adjusting file, group II: WaveOne Gold, and group III: Mtwo rotary system. After instrumentation, the teeth were taken out from the tube and the root surface-adherent debris was collected by washing off the apical area of the tooth with distilled water (1 ml) into a centrifuge tube. The centrifuge tube was kept for 5 days in an incubator at 70°C to permit evaporation of the moisture prior to weighing the dry debris with the aid of an electrical analytical balance. RESULTS: The highest quantity of debris extruded was by the Mtwo rotary system (0.0394 ± 0.880) followed by WaveOne Gold (0.0247 ± 1.030) and self-adjusting file (0.0198 ± 0.102). A statistically significant difference (p < 0.001) was found between the various file systems. CONCLUSION: After considering the drawbacks of this study, apical debris extrusion could be found with all three groups. However, the self-adjusting file demonstrated a significantly reduced quantity of apical debris extrusion compared to the Mtwo rotary system and WaveOne Gold. CLINICAL SIGNIFICANCE: The chief step during the procedure of root canal treatment is the preparation of the infected root canals biomechanically. This preparation may lead to forcing the apical debris into the periapical space through the apical foramen, resulting in host-initiated immunological response which leads to postoperative discomfort and pain. This consequently leads to selection of a specific rotary system for endodontic treatment.


Assuntos
Níquel , Preparo de Canal Radicular , Cavidade Pulpar , Humanos , Titânio , Ápice Dentário/cirurgia
16.
J Contemp Dent Pract ; 22(4): 361-364, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-34267004

RESUMO

AIM AND OBJECTIVE: The present study aims to evaluate the difference in torsional resistance of two reciprocating nickel-titanium (Ni-Ti) rotary files: WaveOne Gold and EdgeOne Fire. MATERIALS AND METHODS: A total of 40 nickel-titanium rotary instruments (n = 40): 20 WaveOne Gold Small (WOGS) and 20 EdgeOne Fire Small (EOFS) were divided into two groups. Each instrument was tested using a torsional resistance device already validated in previous studies to evaluate and compare torsional resistance. The static torsional test was implemented by blocking each instrument at 3 mm from the tip and rotating it until fracture with a reciprocating motion. Torque to fracture (TtF) and fragment length (FL) were measured and statistically analyzed. RESULTS: Statistical analysis of TtF found significant differences between the two groups (p<0.05). The EOFS showed higher TtF if compared to WOGS, with a mean value and a standard deviation of 3.05 ± 0.07 (N cm) against 2.97 ± 0.08 (N cm). Data for FL showed no significant differences (p>0.05) between the two groups. CONCLUSION: According to the results of this study, it is reasonable to assert that EOFS instruments showed a higher torsional resistance if compared to the WOGS. CLINICAL SIGNIFICANCE: As evidenced by this study, EOFS should be considered as a safer solution, in terms of torsional resistance, if compared to WOGS, reducing the risk of intracanal separation due to excessive torsional load.


Assuntos
Níquel , Titânio , Ligas Dentárias , Instrumentos Odontológicos , Desenho de Equipamento , Temperatura Alta , Teste de Materiais , Preparo de Canal Radicular , Torção Mecânica
17.
J Contemp Dent Pract ; 22(4): 427-434, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-34267014

RESUMO

AIM: The aim of this systemic review is to investigate these parameters by analyzing the characteristics of fractured instruments to determine which is the most relevant mechanical stress that induces intracanal separation in vivo. BACKGROUND: The fracture of nickel-titanium (Ni-Ti) instruments is a result of flexural fatigue and torsional fatigue. An electronic search was conducted in MEDLINE database, Web of Science, and Cochrane following preferred reporting items for systematic reviews and meta-analyses guidelines. Data were collected and the key features from the included studies were extracted. Overview quality assessment questionnaire scoring assessed the quality of the articles. A total of 12 articles were selected, where the lowest score was 13. REVIEW RESULTS: Considering Ni-Ti rotary instruments, this overall evaluation comprehends 939 broken instruments with an incidence of fracture of 5%. Out of the 12 selected articles, 10 studies revealed that flexural failure was the predominant mode (range of 62-92%). It appears that motion plays an important role when it comes to mechanisms of fracture. The majority of defects found in hand-operated instruments were in the form of torsional failure. Although the major cause of separation of rotary instruments is flexural fatigue, smaller instruments show more torsional fracture than the larger instruments. The average fragment length was found to be 2.5 mm and 3.35 mm, respectively, for torsional failure and flexural failure. The risk of bias depends on fractographic analysis. CONCLUSION: Flexural fatigue is the predominant mode of fracture in rotary Ni-Ti instruments. The type of motion and size of the instrument seem to affect the mechanism of fracture. Fragment length may show a strong association with the type of fracture mechanism. CLINICAL SIGNIFICANCE: This systemic review found that flexural fatigue is the most relevant mechanical stress that induces intracanal separation in vivo. Moreover, in clinical practice, the fragment length might be an excellent indicator of the type of fracture.


Assuntos
Níquel , Titânio , Ligas Dentárias , Instrumentos Odontológicos , Desenho de Equipamento , Falha de Equipamento , Incidência , Preparo de Canal Radicular , Estresse Mecânico , Torção Mecânica
18.
Vestn Otorinolaringol ; 86(3): 14-19, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34269018

RESUMO

OBJECTIVE: To compare the anatomical and functional results of the ossicular chain reconstruction with classic titanium adjustable prostheses and titanium adjustable prostheses with hydroxyapatite cap. MATERIAL AND METHODS: The 300 patients (360 cases) with chronic suppurative otitis media were examined and operated. The patients are divided into 2 groups. Group A included patients who received an ossicular prosthesis with a hydroxyapatite cap (90 cases with a partial prosthesis and 90 with a full one). Group B included patients who received prostheses without hydroxyapatitis (90 cases with a partial prosthesis and 90 with a complete one). The patients who received a prosthesis with a hydroxyapatite cap were divided into two subgroups, depending on the autotissue, which was placed between the prosthesis cap and the nontympanic membrane: this is an autocartilage plate or perichondrium/fascial graft. The follow-up period after surgery was 38.5±14.4 months (from 12 to 48 months). In the long-term postoperative period, the subjects were assessed the values of the bone-air gap (BAG), the consistency of the nontympanic membrane, and the presence of signs of extrusion of the prosthesis cap. Comparison of anatomical and functional results between patients with full and partial ossicular prostheses was performed separately. RESULTS: A good result in the form of a 20 dB or more dB BAG reduction was achieved in 82.2% of patients who received a partial prosthesis (85 patients in group A and 63 in group B), and in 57.8% of patients who received a complete prosthesis (45 patients in group A and 59 in group B). The BAG values in the long-term period after surgery did not statistically significantly differ between patients who received a prosthesis with a hydroxyapatite cap or a fully titanium one (p=0.939 for patients with full prostheses and p=0.745 for patients with partial prostheses). The placement of cartilage or perichondrium/fascial graft between the hydroxyapatite prosthesis cap and the nontympanic membrane also did not affect the functional outcome (with full prostheses - p=0.651, with partial prostheses - p=0.142). CONCLUSION: It is possible to use ossicular prostheses with a hydroxyapatite cap without placing an autocartilaginous plate between the nontympanic membrane and the cap of the prosthesis. In the long term period, functional and anatomical results with hydroxyapatite cap prostheses do not differ statistically significantly from those with all-titanium prostheses.


Assuntos
Prótese Ossicular , Substituição Ossicular , Durapatita , Humanos , Estudos Retrospectivos , Titânio , Resultado do Tratamento , Timpanoplastia
19.
J Nanosci Nanotechnol ; 21(12): 5906-5911, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34229785

RESUMO

Bearings play a vital role in the operation of a two-axis system. Long-term bearing use inevitably produce bubbles and frictional damage. Therefore, the protection of bearings is critical for the stable operation of a two-axis system. In this study, a TiO2 nanofilm is used to physically protect a bearing. The discretization method is used to analyse the cavitation process. Cavitation primarily occurs on the front surface of the pad during bearing operation. A finite element analysis of a bearing pad coated and not coated with TiO2 nanofilms shows that TiO2 nanofilms can effectively absorb the cavitation force exerted on pads, thereby reducing inflicted damage. Moreover, the TiO2 nanofilm reduces the friction coefficient of the pad surface, promoting good bearing capacity of the bearing during rotation. The TiO2 nanofilm serves as a protective layer that improves the anti-wear and bearing performance of a two-axis system.


Assuntos
Pele , Titânio , Análise de Elementos Finitos , Fricção
20.
BMJ Case Rep ; 14(7)2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34244185

RESUMO

Following wrist trauma due to a karate accident, an 18-year-old male patient developed non-union of the scaphoid with proximal pole necrosis and significant scapholunate gap from an evident scapholunate interosseous ligament (SLIL) injury. A custom-made 3D-printed titanium implant was used for scaphoid replacement and SLIL reconstruction. Good clinical and radiographic outcomes were observed at his 2-year follow-up. Custom-made 3D-printed titanium implants are thought to provide a surgical solution for patients requiring site-specific scaphoid replacement while allowing the reconstruction of the scapholunate ligament.


Assuntos
Osso Semilunar , Osso Escafoide , Adolescente , Humanos , Ligamentos Articulares/diagnóstico por imagem , Ligamentos Articulares/cirurgia , Osso Semilunar/diagnóstico por imagem , Osso Semilunar/cirurgia , Masculino , Impressão Tridimensional , Osso Escafoide/diagnóstico por imagem , Osso Escafoide/cirurgia , Titânio , Articulação do Punho/diagnóstico por imagem , Articulação do Punho/cirurgia
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