Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 124.939
Filtrar
1.
Braz. j. oral sci ; 21: e224265, jan.-dez. 2022. tab
Artículo en Inglés | LILACS, BBO - Odontología | ID: biblio-1354719

RESUMEN

Aim: This study assessed the color and translucency stability of a polymer infiltrated ceramic network (PICN) and compared it with a resin composite (RC) and a feldspathic ceramic (FEL). Methods: Disc-shaped samples of a PICN (Vita Enamic), a feldspathic ceramic (Vitablocks Mark II), and a resin composite (Brava block) were prepared from CAD/CAM blocks. PICN and RC surfaces were finished with a sequence of polishing discs and diamond paste. FEL samples received a glaze layer. The samples were subjected to 30-min immersions in red wine twice a day for 30 days. CIEL*a*b* coordinates were assessed with a spectrophotometer at baseline and after 15 and 30 days of immersion. Color alteration (ΔE00) and translucency parameter (TP00) were calculated with CIEDE2000. Average roughness was measured before the staining procedures. Color difference and translucency data were analyzed with repeated-measures ANOVA and Tukey's tests. Roughness was analyzed with the Kruskal-Wallis test. Results: Roughness was similar among the experimental groups. All materials had their color alteration significantly increased from 15 to 30 days of staining. PICN reached an intermediate ΔE00 between FEL and RC at 15 days. PICN revealed a color alteration as high as the composite after 30 days. No statistical difference was observed regarding translucency. Conclusion: PICN was not as color stable as the feldspathic ceramic at the end of the study. Its color alteration was comparable to the resin composite when exposed to red wine. However, the translucency of the tested materials was stable throughout the 30-day staining


Asunto(s)
Propiedades de Superficie , Ensayo de Materiales , Cerámica , Diseño Asistido por Computadora , Color , Resinas Compuestas
2.
J Nanobiotechnology ; 20(1): 365, 2022 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-35933376

RESUMEN

The failure of orthopedic and dental implants is mainly caused by biomaterial-associated infections and poor osseointegration. Surface modification of biomedical materials plays a significant role in enhancing osseointegration and anti-bacterial infection. In this work, a non-linear relationship between the micro/nano surface structures and the femtosecond laser processing parameters was successfully established based on an artificial neural network. Then a controllable functional surface with silver nanoparticles (AgNPs) to was produced to improve the cytocompatibility and antibacterial properties of biomedical titanium alloy. The surface topography, wettability, and Ag+ release were carefully investigated. The effects of these characteristics on antibacterial activity and cytocompatibilty were also evaluated. Results show that the prepared surface is hydrophobic, which can prevent the burst release of Ag+ in the initial stage. The prepared surface also shows both good cytocompatibility toward the murine calvarial preosteoblasts MC3T3-E1 cells (derived from Mus musculus (mouse) calvaria) and good antibacterial effects against Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria, which is caused by the combined effect of appropriate micro/nano-structured feature and reasonable Ag+ release rate. We do not only clarify the antibacterial mechanism but also demonstrate the possibility of balancing the antibacterial and osteointegration-promoting properties by micro/nano-structures. The reported method offers an effective strategy for the patterned surface modification of implants.


Asunto(s)
Nanopartículas del Metal , Plata , Animales , Antibacterianos/química , Antibacterianos/farmacología , Materiales Biocompatibles/farmacología , Escherichia coli , Rayos Láser , Nanopartículas del Metal/química , Ratones , Redes Neurales de la Computación , Plata/química , Plata/farmacología , Staphylococcus aureus , Propiedades de Superficie , Titanio/química
3.
Biomater Adv ; 138: 212875, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35913254

RESUMEN

A newly developed ß-Ti alloy based on the Ti-Nb-Zr-Ta system (Ti20Nb20Zr4Ta) has been subjected to Plasma Electrolytic Oxidation (PEO) treatment to obtain a multifunctional ceramic-like (TiO2) coating with superior tribocorrosion (wear and corrosion) resistance and improved biocompatibility. For this aim, elements such as Ca, P, and Ag NPs have been incorporated into the oxide film to obtain bioactive and biocide properties. The chemical composition and morphology of the TiO2-PEO coating was characterized, and its multifunctionality was addressed by several means, including antibacterial activity assessment, formation of bone-like apatite, metallic ion release evaluation, in vitro cellular response analysis, and corrosion and tribocorrosion tests in artificial saliva. The developed coatings enhanced the corrosion and tribocorrosion resistance of the bare alloy and exhibited antibacterial ability with low cytotoxicity and negligible ion release. Furthermore, they were able to sustain MC3T3-E1 preosteoblast viability/proliferation and osteogenic differentiation. Altogether, the results obtained demonstrate the potential of the TiO2 coating incorporating Ca, P, and Ag NPs to be used for dental applications.


Asunto(s)
Aleaciones , Materiales Biocompatibles Revestidos , Aleaciones/química , Antibacterianos/farmacología , Materiales Biocompatibles Revestidos/química , Osteogénesis , Propiedades de Superficie , Titanio
4.
Philos Trans A Math Phys Eng Sci ; 380(2232): 20210344, 2022 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-35909364

RESUMEN

Microbial biofouling on polymer surfaces can lead to their biodeterioration. This may result in deterioration of the surface, leading to cracking and fracturing. Fungal spores from Aspergillus niger 1957, Aspergillus niger 1988 and Aureobasidium pullulans were tested to determine their strength of attachment on three surfaces, p(γ-MPS-co-MMA), p(γ-MPS-co-LMA) and spin-coated poly(methyl methacrylate) (PMMAsc), using lateral force measurements. The results demonstrate that A. niger 1957 and A. niger 1988 spores were most easily removed from the p(γ-MPS-co-MMA) surface, which was the surface with the highest Ra value. The A. niger 1957 and A. pullulans spores were most difficult to remove from the PMMAsc surface, which was the hardest surface. A. niger 1988 spores were the most difficult to remove from p(γ-MPS-co-LMA), the most hydrophobic surface. The results with A. pullulans were difficult to elucidate since the spores bound to all three surfaces and were removed with similar rates of force. The lateral force results demonstrate that spore attachment to a surface is a multi-factorial process, and independent surface and microbial factors influence spore binding. Thus, each environmental scenario needs to be considered on an individual basis, since a solution to one biofouling issue will probably not translate across to other systems. This article is part of the theme issue 'Nanocracks in nature and industry'.


Asunto(s)
Aspergillus niger , Fenómenos Mecánicos , Interacciones Hidrofóbicas e Hidrofílicas , Esporas Fúngicas , Propiedades de Superficie
5.
PLoS One ; 17(8): e0272387, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35913977

RESUMEN

Titanium alloys have great potential in ultra-precision situations due to the excellent properties, such as high corrosion resistance, high specific-strength and high biocompatibility. However, the application of titanium alloys in ultra-precision field is limited by the poor machinability. There are difficulties in obtaining the optical surface. In this study, the possibility for obtaining optically graded surfaces of titanium alloys by ultra-precision polishing was investigated. Before the ultra-precision polishing, ultra-precision turning with a single point diamond tool was used to get all sample surfaces. But, titanium alloy is difficult to obtain good surface quality by ultra-precision diamond turning. The samples results confirmed that most of the surface roughness values are higher than 30 nm. In order to explore the polishing process, a large number of ultra-precision polishing experiments were conducted. In addition, the effects of different ultra-precision polishing parameters on the surface profiles of titanium alloy Ti6Al4V were investigated in depth. The results show that the average values of surface roughness of titanium alloy parts with ultra-precision turning can be further reduced by 70% or so by ultra-precision polishing. Using a reasonable combination of high spindle speed and large cutting depth, the value of surface roughness can even be lower than 2 nm.


Asunto(s)
Aleaciones , Titanio , Pulido Dental , Diamante , Ensayo de Materiales , Propiedades de Superficie
6.
PLoS One ; 17(8): e0272486, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35917303

RESUMEN

The study of the intimate connection occurring at the interface between cells and titanium implant surfaces is a major challenge for dental materials scientists. Indeed, several imaging techniques have been developed and optimized in the last decades, but an optimal method has not been described yet. The combination of the scanning electron microscopy (SEM) with a focused ion beam (FIB), represents a pioneering and interesting tool to allow the investigation of the relationship occurring at the interface between cells and biomaterials, including titanium. However, major caveats concerning the nature of the biological structures, which are not conductive materials, and the physico-chemical properties of titanium (i.e. color, surface topography), require a fine and accurate preparation of the sample before its imaging. Hence, the aim of the present work is to provide a suitable protocol for cell-titanium sample preparation before imaging by SEM-FIB. The concepts presented in this paper are also transferrable to other fields of biomaterials research.


Asunto(s)
Materiales Biocompatibles , Titanio , Materiales Biocompatibles/química , Adhesión Celular , Microscopía Electrónica de Rastreo , Prótesis e Implantes , Propiedades de Superficie , Titanio/química
7.
Biointerphases ; 17(4): 041201, 2022 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-35931562

RESUMEN

In this Tutorial series, we aim to provide an accessible introduction to vibrational sum frequency generation (VSFG) spectroscopy, targeted toward people entering the VSFG world without a rigorous formal background in optical physics or nonlinear spectroscopy. In this article, we discuss in detail the processes of collecting and processing VSFG data, and user-friendly processing software (sfgtools) is provided for use by people new to the field. Some discussion of analyzing VSFG spectra is also given, specifically with a discussion of fitting homodyne VSFG spectra, and a discussion of what can be learned (both qualitatively and quantitatively) from VSFG spectra.


Asunto(s)
Vibración , Humanos , Análisis Espectral/métodos , Propiedades de Superficie
8.
Sci Rep ; 12(1): 13328, 2022 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-35922439

RESUMEN

The use of metal deposition has been limited to a limited number of applicable samples due to the increased temperature caused by accelerated electron impact on the substrate surface. The surfaces of various biological samples have a nanoscale structure with specific properties, which have been simulated in numerous studies. However, no examples of nano/microscale reproductions of biological surface features have used moulds. In this study, a mould that imitates the surface shape of a cellular-level biological material was fabricated, for the first time, and the shape was successfully reproduced using the mould. Al thin films were deposited on bovine sperm using magnetron sputtering without thermal denaturation with a cathode operating at a biological temperature. It is difficult to deposit films used as metal coatings on pre-treated biological materials at temperatures below 40 °C during evaporation. The Al thin film was peeled off and used as a mould to reproduce the shape of the sperm with high accuracy using a polymer. The results of this study represent a major innovation in reproducible biomimetic moulding technology, demonstrating biological temperature sputtering. We expect our non-destructive metal deposition and metal nano-moulding methods for biological samples to be the basis for the effective utilization of various biological structures.


Asunto(s)
Metales , Semen , Animales , Bovinos , Masculino , Reproducción , Propiedades de Superficie , Temperatura
9.
BMC Oral Health ; 22(1): 321, 2022 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-35915423

RESUMEN

The long-term color stability and gloss retention of resin composites are among the crucial factors that affect the clinical longevity of esthetic restorations, especially in anterior teeth. This study evaluated the effect of artificial aging by immersion in different storage media and thermocycling on color and gloss of dental single-shade resin composite (Omnichroma) versus multi-shade one (Filtek Z350XT). One hundred resin-composite disc-shaped specimens were used, 50 from each group, Omnichroma and Filtek Z350XT. Ten specimens from each material acted as control group (incubated in saliva). For each material, 40 specimens were divided according to the artificial-aging protocol (immersion at 37 °C for 12 days or thermocycling for 10,000 cycles) and storage media (tea, red wine). Color and gloss were measured before and after artificial aging. Color difference (∆E00) was compared with perceptibility threshold and acceptability threshold. Data were statistically analyzed; independent t test was used to compare results between two tested materials, while two-way ANOVA was used to compare results among the different immersion media within the same material. Artificial aging (immersion or thermocycling) in tea and red wine led to significant color changes and gloss reduction in both materials (P < 0.05), in contrast to control group. Red wine produced highest color differences. Both dental resin-composites; the single-shade (Omnichroma) and multi-shade (Filtek Z350XT) displayed unacceptable discoloration and gloss reduction after artificial-aging in tea and red-wine by immersion or thermocycling simulating one-year clinical-service.


Asunto(s)
Resinas Compuestas , , Color , Humanos , Ensayo de Materiales , Propiedades de Superficie
10.
São Paulo; s.n; 20220720. 185 p.
Tesis en Portugués | LILACS, BBO - Odontología | ID: biblio-1379715

RESUMEN

O desgaste dentário é um processo de perda de estrutura dental, de etiologia multifatorial, com incidência crescente na população e ocasionado, principalmente, pela frequência do contato da superfície dentária com substâncias químicas e mecânicas, resultantes da alimentação e de hábitos orais. Os efeitos da ação dos desafios químicos e/ou mecânicos no dente, hígido ou restaurado, podem variar conforme as propriedades e características do substrato dentina, material restaurador. O estudo objetivou analisar os efeitos dos desafios erosivo (DE) e erosivo-abrasivo (DEA) na superfície de diferentes materiais restauradores (MR), sistemas adesivos (SA) e da dentina adjacente às restaurações (DAR). Molares humanos hígidos (n=75) foram limpos e preparados até obtenção de dentina oclusal uniforme. Os espécimes foram aleatoriamente divididos em 5 grupos (n=15). Na superfície dentinária, uma cavidade 4 x 2 mm foi confeccionada por meio de uma ponta diamantada, e restaurada por diferentes tipos de SR: Amaris® (AMA), Beautifil® II (BEA), ClearfilTM SE Bond 2 (CFB), FL-Bond II (FLB) e RIVA Self Cure (RIVA). Após restauração, a superfície do espécime foi delimitada em três partes duas, nas extremidades, que foram protegidas por fita adesiva anticorrosiva, e uma, intermediária (2 mm), que foi deixada livre para exposição da área aos desafios. No DE, o espécime foi imerso em solução de ácido cítrico 1% (pH 2.3) por dois min, seguido de imersão em saliva artificial por 60 min. Esse ciclo foi realizado durante 5 dias (6x/dia). No DEA, os espécimes foram submetidos ao mesmo DE descrito, porém foram escovados em máquina de escovação (escova macia, 45 ciclos/150g/15s), 2x/dia (após 30 min do primeiro e do último ciclo erosivo do dia). Os efeitos dos desafios foram avaliados pela análise das propriedades de perda de superfície (PS, m) e rugosidade superficial (RS, m) (Perfilometria óptica); e dureza superficial (HB, nanoindentação, Kg/mm2). Os dados foram analisados estatisticamente (p=0.05) pelos testes ANOVA, de Tukey e pela Correlação Linear de Pearson. Após desafios, as DAR de todos os grupos apresentaram elevada perda e diminuição na dureza. O DE ocasionou maior PS na dentina (PS>20 m). Não houve diferença entre a rugosidade dos materiais restauradores após desafios. O material RIVA apresentou elevada perda (PS>2 m), elevada rugosidade (RS=0.93048±0.2) e diminuição na dureza (HB<35 Kg/mm2) após desafios, principalmente após escovação. A rugosidade dentinária de AMA+CFB (RS=0.61921±0.1) foi menor após abrasão. Os desafios agiram igualmente sobre a dureza da interface adesiva. A dureza da interface de BEA+FLB (HB=16.97627±2.32) foi menor após escovação. Após erosão, a dureza dos materiais bioativos BEA, FLB e RIVA reduziram. Os efeitos observados dependeram do tipo de desafio e substrato envolvido no processo. A ação isolada do ácido cítrico foi mais agressiva no substrato dentinário. Os desafios tiveram efeitos sobre as propriedades dos materiais restauradores, principalmente nas dos bioativos. Nenhum material foi eficaz contra a desmineralização severa da dentina.


Asunto(s)
Propiedades de Superficie , Abrasión de los Dientes , Desgaste de los Dientes
11.
Oper Dent ; 47(3): E131-E151, 2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35776960

RESUMEN

PURPOSE: The current gold standard measure to assess polishing efficacy is surface roughness (SR) assessed in laboratory research. Specular gloss (SG) has been negatively correlated to SR, which raises the following question: Can SG be used to accurately determine the effectiveness of a finishing/polishing procedure in direct resin composites? METHODS: A systematic approach and search strategy, following Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, was developed and conducted in five electronic databases: PubMed/Medline, Scopus, Web of Science, EMBASE (Ovid), and SciELO/LILACS to identify laboratory studies that assessed SR and SG, simultaneously, of resin composites, without date or language restriction. Risk of bias assessment was carried out by two reviewers, independently. From the extracted quantitative data of SG/SR, regression analyses were performed, and a linear mixed-effects prediction model was derived using the nimble package in R (v4.0.3). RESULTS: A total of 928 potential studies were found, out of which, 13 were eligible after criterion screening. Experimental groups featured 31 resin composites of six different filler types, with the most common being microhybrids followed by nanohybrids. More than half of the studies initially reported a linear correlation between SR and SG, which ranged from r2 = 0.34-0.96. Taking into account the regression analysis and prediction model posteriorly performed, the corresponding SG threshold for 0.2 µm is estimated to be >55 GU. Most of the evidence was classified as moderate or high risk of bias. CONCLUSION: SG is universally correlated to SR in polymers, and a reference value of >55 GU is proposed, above which samples are considered well polished.


Asunto(s)
Pulido Dental , Polímeros , Resinas Compuestas/uso terapéutico , Pulido Dental/métodos , Ensayo de Materiales , Propiedades de Superficie
12.
ACS Appl Mater Interfaces ; 14(27): 30571-30581, 2022 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-35776897

RESUMEN

Constructing hierarchical hybrid structures is considered a facile method to improve the osseointegration of implants. Herein, a hierarchical micro-/submicro-/nanostructured surface feature of Ti6Al4V implants (3DAT group) was successfully constructed by combining the inherently formed three-dimensional (3D)-printed microscale topography, acid-etched sub-micropits, and anodized nanotubes. Compared with the classical SLA surface, the microscale topography and sub-micropits increased the three-dimensional space for the cell growth and mechanical stability of implants, while the modification of nanotubes dramatically improved the surface hydrophilicity, protein adsorption, and biomineralization. Most importantly, the 3DAT surface feature possessed excellent osteogenic performance in vitro and in vivo, with the involvement of semaphorin 7A (Sema7A) as revealed by RNA-seq through the ITGB1/FAK/ERK signaling pathway. The present study suggested that the hierarchically structured surface design strategy could accelerate the osseointegration rate of 3D-printed Ti6Al4V implants, promising personalized reconstruction of bone defects.


Asunto(s)
Osteogénesis , Titanio , Aleaciones , Oseointegración , Impresión Tridimensional , Transducción de Señal , Propiedades de Superficie , Titanio/química
13.
Sci Rep ; 12(1): 11556, 2022 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-35798824

RESUMEN

The roughness and wettability of surfaces exploited by free-ranging geckos can be highly variable and attachment to these substrates is context dependent (e.g., presence or absence of surface water). Although previous studies focus on the effect of these variables on attachment independently, geckos encounter a variety of conditions in their natural environment simultaneously. Here, we measured maximum shear load of geckos in air and when their toes were submerged underwater on substrates that varied in both surface roughness and wettability. Gecko attachment was greater in water than in air on smooth and rough hydrophobic substrates, and attachment to rough hydrophilic substrates did not differ when tested in air or water. Attachment varied considerably with surface roughness and characterization revealed that routine measurements of root mean square height can misrepresent the complexity of roughness, especially when measured with single instruments. We used surface roughness power spectra to characterize substrate surface roughness and examined the relationship between gecko attachment performance across the power spectra. This comparison suggests that roughness wavelengths less than 70 nm predominantly dictate gecko attachment. This study highlights the complexity of attachment in natural conditions and the need for comprehensive surface characterization when studying biological adhesive system performance.


Asunto(s)
Lagartos , Adhesividad , Animales , Fenómenos Biomecánicos , Propiedades de Superficie , Agua
14.
Int J Mol Sci ; 23(13)2022 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-35806339

RESUMEN

The techniques used in oral implantology to remove bacterial biofilm from the surface of implants by machining the titanium surface (implantoplasty) or by placing rough dental implants through friction with the cortical bone generate a large release of particles. In this work, we performed a simulation of particle generation following clinical protocols. The particles were characterized for commercially pure titanium with particle sizes of 5, 10, 15, and 30 µm. The aim was to determine the effect of particle size and chemical composition of the implant on the immune response. For this purpose, their morphology and possible contamination were characterized by scanning electron microscopy and X-ray microanalysis. In addition, the granulometry, specific surface area, release of metal ions into the medium, and studies of cytocompatibility, gene expression, and cytokine release linked to the inflammatory process were studied. The release of ions for titanium particles showed levels below 800 ppb for all sizes. Smaller particle sizes showed less cytotoxicity, although particles of 15 µm presented higher levels of cytocompatibility. In addition, inflammatory markers (TNFα and Il-1ß) were higher compared to larger titanium. Specifically, particles of 15 µm presented a lower proinflammatory and higher anti-inflammatory response as characterized by gene expression and cytokine release, compared to control or smaller particles. Therefore, in general, there is a greater tendency for smaller particles to produce greater toxicity and a greater proinflammatory response.


Asunto(s)
Implantes Dentales , Titanio , Citocinas , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Propiedades de Superficie , Titanio/análisis
15.
Int J Mol Sci ; 23(13)2022 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-35806443

RESUMEN

Surface coatings of materials by polysaccharide polymers are an acknowledged strategy to modulate interfacial biocompatibility. Polysaccharides from various algal species represent an attractive source of structurally diverse compounds that have found application in the biomedical field. Furcellaran obtained from the red algae Furcellaria lumbricalis is a potential candidate for biomedical applications due to its gelation properties and mechanical strength. In the present study, immobilization of furcellaran onto polyethylene terephthalate surfaces by a multistep approach was studied. In this approach, N-allylmethylamine was grafted onto a functionalized polyethylene terephthalate (PET) surface via air plasma treatment. Furcellaran, as a bioactive agent, was anchored on such substrates. Surface characteristics were measured by means of contact angle measurements, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Subsequently, samples were subjected to selected cell interaction assays, such as antibacterial activity, anticoagulant activity, fibroblasts and stem cell cytocompatibility, to investigate the Furcellaran potential in biomedical applications. Based on these results, furcellaran-coated PET films showed significantly improved embryonic stem cell (ESC) proliferation compared to the initial untreated material.


Asunto(s)
Alginatos , Tereftalatos Polietilenos , Antibacterianos/farmacología , Gomas de Plantas , Tereftalatos Polietilenos/química , Polímeros/química , Propiedades de Superficie
16.
Molecules ; 27(13)2022 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-35807482

RESUMEN

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) on cluster-assembled super-hydrophilic nanoporous titania films deposited on hydrophobic conductive-polymer substrates feature a unique combination of surface properties that significantly improve the possibilities of capturing and processing biological samples before and during the MALDI-MS analysis without changing the selected sample target (multi-dimensional MALDI-MS). In contrast to pure hydrophobic surfaces, such films promote a remarkable biologically active film porosity at the nanoscale due to the soft assembling of ultrafine atomic clusters. This unique combination of nanoscale porosity and super-hydrophilicity provides room for effective sample capturing, while the hydrophilic-hydrophobic discontinuity at the border of the dot-patterned film acts as a wettability-driven containment for sample/reagent droplets. In the present work, we evaluate the performance of such advanced surface engineered reactive containments for their benefit in protein sample processing and characterization. We shortly discuss the advantages resulting from the introduction of the described chips in the MALDI-MS workflow in the healthcare/clinical context and in MALDI-MS bioimaging (MALDI-MSI).


Asunto(s)
Nanoporos , Interacciones Hidrofóbicas e Hidrofílicas , Polímeros , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Propiedades de Superficie
17.
Comput Intell Neurosci ; 2022: 1589209, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35837209

RESUMEN

Objective: To explore the application effect of new material after surface modification of zirconia ceramics and patient evaluation. Methods: A total of 60 patients with tooth defect treated in our hospital from April 2020 to April 2021 were selected as the study subjects and randomly divided into the control group and experimental group, with 30 cases each. The patients in the control group were treated with glass-ceramics, and those in the experimental group received LiSi surface treatment, so as to compare the application effect and patients' evaluation between the two groups. Results: Between the two groups, no obvious differences in surface loss, adhesive strength, and transmittance at 3 months, 6 months, and 1 year were not observed (P > 0.05); and after intervention, the score on dental aesthetics, hardness value, and occlusal force were obviously higher in the experimental group than in the control group (P < 0.001). Conclusion: The new material enables forming an acid etchable coating on the zirconia surface, increases the adhesive strength, and achieves an aesthetic degree that is welcomed by the patients; meanwhile, after grinding, the edge is defect free and the tightness is higher. Further research will help to establish a better solution for patients.


Asunto(s)
Cerámica , Circonio , Humanos , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Propiedades de Superficie
18.
Polim Med ; 52(1): 11-16, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35801996

RESUMEN

BACKGROUND: Resin composites have various applications. At the same time, they have some drawbacks, such as polymerization shrinkage. Conventional composites are polymerized in 2-mm thick layers. However, in posterior restoration, the 2-mm depth of cure is not satisfactory. To find a solution, resin composites have been vastly improved in terms of fillers, matrix and initiators. OBJECTIVES: To evaluate polymerization properties and physical characteristics of fiber-reinforced composites and compare them with bulk-fill composites that are designed for large posterior restorations. MATERIAL AND METHODS: Samples were prepared from each resin composite. The 3-point bending test was performed to evaluate the flexural strength of all composites. The depth of cure of the composite from 1 mm to 4 mm of depth was analyzed using Vickers hardness test (VHN). To analyze the degree of conversion, Fourier-transform infrared spectroscopy (FTIR) of the top and bottom surfaces of the samples with 4-mm thickness was calculated. The data were analyzed using one-way analysis of variance (ANOVA) test followed by post hoc test (95% confidence interval (95% CI)). RESULTS: The Filtek showed the highest flexural strength followed by everX and X-tra fil. At 1-mm depth, X-tra fil had the highest and Gradia had the lowest microhardness. At the 4-mm depth, the microhardness trend was as follows: everX > Filtek > X-tra fil > Gradia > Beautifil. The everX composite had the lowest reduction of the degree of conversion at 4-mm thickness, which showed a significant difference in comparison with Filtek, Gradia and X-tra fil composites. CONCLUSIONS: Based on the results of our study, it can be concluded that the fiber-reinforced composite everX showed more favorable results regarding polymerization properties, such as the degree of conversion and the depth of cure. However, the flexural strength results in Filtek were better than those in everX.


Asunto(s)
Resinas Compuestas , Materiales Dentales , Resinas Compuestas/química , Dureza , Pruebas de Dureza , Ensayo de Materiales , Polimerizacion , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie
19.
Orthod Fr ; 93(2): 101-109, 2022 06 01.
Artículo en Francés | MEDLINE | ID: mdl-35818280

RESUMEN

Introduction: The number of adult patients who seek an orthodontic treatment is increasing. These patients often have lithium disilicate ceramic restorations. The orthodontist has to find a procedure to bond effectively brackets to these restorations. In 2011, a new family of adhesives was introduced, universal adhesives, which are capable of bonding to ceramic and are said "multi-mode" because they can be used in etching-rinse or self-etching protocol on tooth surface. The objective of this in vitro study was to evaluate the shear bond strength (SBS) of metal brackets to lithium disilicate ceramic support using a universal adhesive. Materials and Methods: Forty machinable lithium disilicate blocks (IPS e.max CAD, Ivoclar) were prepared according manufacturer's instructions. Each specimen was randomly assigned to one of four groups (n=9 or 10) defined by the pretreatment protocol. Protocol 1: Hydrofluoric Acid 9 % (HF) + Silane + Orthodontic adhesive (Transbond™ XT Light Cure Adhesive Primer, 3M ESPE), protocol 2: HF + Universal adhesive (UA) (Scotchbond Universal®, 3M ESPE), protocol 3: UA only, protocol 4 : Monobond Etch & Prime® (Ivoclar) + UA. Then, a bracket of upper cuspid (3M ESPE) was bonded to each specimen with a composite resin (Transbond™ XT, 3M ESPE). SBS was measured between ceramic and bracket with a universal testing machine. A one-way ANOVA (ANalysis Of Variance) followed by Tukey's post-hoc test was performed to investigate SBS differences between groups. Results: Protocol 2 (43 MPa) and protocol 4 (36 MPa) showed the highest SBS values and were statistically different from protocol 1 (25 MPa) and protocol 3 (21 MPa). Conclusion: Despite the lower bond values obtained in the study, but higher than the minimum expected, the application of UA alone appears to be a safe procedure that seems to provide sufficiently strong and resistant bonding between the ceramic and the bracket. However, clinical studies are needed before a recommendation can be made.


Introduction: Les traitements orthodontiques chez l'adulte se démocratisent. Ces patients ont souvent des restaurations en céramique en disilicate de lithium, sur lesquelles l'orthodontiste doit être à même de coller efficacement ses attaches. Or, les adhésifs universels, nouvelle famille d'adhésifs introduite en 2011, présentent un potentiel d'adhésion aux céramiques, en plus de pouvoir être utilisés en mode mordançage-rinçage ou auto-mordançant. L'objectif de cette étude in vitro était d'évaluer l'adhérence d'attaches métalliques à ces céramiques à l'aide d'un adhésif universel. Matériels et méthodes: Quarante blocs de céramique en disilicate de lithium (IPS e.max CAD, Ivoclar) ont été préparés selon les recommandations de cristallisation du fabricant. Chaque échantillon a été ensuite réparti aléatoirement en quatre groupes (n = 9 ou 10) selon le protocole de traitement de surface appliqué. Protocole 1 : Acide Fluorhydrique 9 % (HF) + Silane + Adhésif orthodontique (Transbond™ XT Light Cure Adhesive Primer, 3M ESPE), protocole 2 : HF + Adhésif universel (AU) (Scotchbond Universal®, 3M ESPE), protocole 3 : AU uniquement, protocole 4 : Monobond Etch & Prime® (Ivoclar) + AU. Une attache métallique de canine maxillaire (3M ESPE) a ensuite été collée sur chaque échantillon avec une résine composite (Transbond™ XT, 3M ESPE). La résistance en cisaillement a ensuite été mesurée entre la céramique et l'attache métallique. Une ANOVA (ANalysis Of Variance ou analyse de variance) suivie du test post-hoc de Tukey ont été réalisés pour étudier les différences d'adhérence entre les groupes. Résultats: Les protocoles 2 (43 MPa) et 4 (36 MPa) présentent des valeurs d'adhérence significativement supérieures à celles des protocoles 1 (25MPa) et 3 (21 MPa). Conclusion: Malgré de plus faibles valeurs d'adhérence obtenues dans l'étude, mais supérieures à celles minimales attendues, l'application seule de l'adhésif universel semble être une procédure sans danger qui procure une adhésion suffisamment forte et résistante entre la céramique et l'attache. Des études cliniques sont cependant nécessaires avant d'émettre une recommandation.


Asunto(s)
Recubrimiento Dental Adhesivo , Soportes Ortodóncicos , Cerámica/química , Recubrimiento Dental Adhesivo/métodos , Cementos Dentales/química , Porcelana Dental , Humanos , Ácido Fluorhídrico , Ensayo de Materiales , Propiedades de Superficie
20.
J Clin Pediatr Dent ; 46(3): 211-218, 2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35830639

RESUMEN

OBJECTIVES: With the recent improvements in technology, the expectation of minimal invasion and maximal comfort in caries removal techniques is increasing. This study aims to examine the effectiveness of six caries removal methods in primary teeth. STUDY DESIGN: Sixty primary molars (10 teeth in each groups) were used. The groups were: Group I (Tungsten Carbide Bur), Group II (Sono abrasion), Group III (Air abrasion), Group IV (Carisolv), Group V (Er:YAG Laser), Group VI (ART). In micro-CT scanning, mineral density at the cavity floor was examined before and after caries removal. After caries removal, the patency of the dentinal tubules was examined in two teeth from each group on SEM images. Statistical analyses were performed using Kruskal-Wallis, Wilcoxon tests. RESULTS: For six different caries removal methods, tooth mineral (inorganic, total) densities at cavity floors were compared among the groups after the procedures, and no statistically significant difference was found (p>0.05). On the SEM images, it was seen that the dentinal tubules were exposed and no smear layer was formed in the Carisolv group. Significant rough surfaces were exposed in the laser group. CONCLUSION: It was observed that alternative caries removal methods are at least as effective as the traditional method in primary teeth for clinical applications.


Asunto(s)
Caries Dental , Preparación de la Cavidad Dental , Abrasión Dental por Aire , Caries Dental/diagnóstico por imagen , Caries Dental/terapia , Susceptibilidad a Caries Dentarias , Preparación de la Cavidad Dental/métodos , Dentina/diagnóstico por imagen , Humanos , Microscopía Electrónica de Rastreo , Minerales , Propiedades de Superficie , Diente Primario , Microtomografía por Rayos X
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...