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1.
Carbohydr Polym ; 300: 120229, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36372501

RESUMO

Hydrogels as flexible sensor have attracted significant attention due to its conductivity, stretchability and flexibility. However, it is still a great challenge to prepare hydrogels that simultaneously possess high strength, anti-fatigue, self-adhesion, and anti-freezing. Herein, a multifunctional dual-network hydrogel was prepared by in situ polymerization of acrylic monomer in chitosan chains, and coordinated with aluminum chloride and glycerol. Based on chain entanglement, hydrogen bonding and coordination interactions, this dual-network hydrogel exhibited excellent mechanical properties, good fatigue resistance, and excellent adhesion performance. It can be used as a strain sensor for its stable conductivity and high sensitivity, which could monitor both large human motions and subtle motions. Due to the presence of glycerol, the hydrogel showed outstanding freezing resistance and still kept flexible and conductive even at low temperatures (-20 °C). This hydrogel can be applied as a flexible wearable sensor for monitoring human motion in extreme low-temperature condition.


Assuntos
Adesivos , Hidrogéis , Humanos , Cimentos de Resina , Glicerol , Condutividade Elétrica
2.
Methods Mol Biol ; 2578: 53-62, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36152280

RESUMO

Recent advances in biosensing analytical platforms have brought relevant outcomes for novel diagnostic and therapy-oriented applications. In this context, 3D droplet microarrays, where hydrogels are used as matrices to stably entrap biomolecules onto analytical surfaces, potentially provide relevant advantages over conventional 2D assays, such as increased loading capacity, lower nonspecific binding, and enhanced signal-to-noise ratio. Here, we describe a hybrid hydrogel composed of a self-assembling peptide and commercial agarose (AG) as a suitable matrix for 3D microarray bioassays. The hybrid hydrogel is printable and self-adhesive and allows analyte diffusion. As a showcase example, we describe its application in a diagnostic immunoassay for the detection of SARS-CoV-2 infection.


Assuntos
COVID-19 , Hidrogéis , COVID-19/diagnóstico , Humanos , Hidrogéis/química , Imunoensaio , Peptídeos/química , Cimentos de Resina , SARS-CoV-2 , Sefarose
3.
J Mech Behav Biomed Mater ; 137: 105539, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36343522

RESUMO

PURPOSE: The effect of hydroxyapatite (HAp) coating layer on mechanical and optical properties at bonding interface of high-performance polymers (HPPs) used in computer-aided design (CAD)/computer-aided manufacture (CAM) technology was investigated in this in vitro study. MATERIALS AND METHODS: Two hundred-twenty specimens were divided into two material groups (n = 110): polyetheretherketone (PEEK, KERA® starPEEK) and polyetherketoneketone (PEKK, Pekkton® ivory). For mechanical testing, each group was divided into five surface pretreatment subgroups and a control group (n = 10): HAp coating (1%,3%, 5%, and 10% concentrations) and sandblasting with 110-µm Al2O3 particles. For optical testing, each group was divided into five subgroups (n = 10): HAp coating (1%, 3%, 5%, and 10% concentrations) and control. The effects of the HAp coating on the optical changes and shear bond strength (SBS) of the specimens were investigated. Data was statistically analyzed by one-way ANOVA and Tukey's post-hoc test. Failure modes and surface properties of the specimens were examined by scanning electron microscopy (SEM) and coupled electron dispersive spectroscopy (EDS). RESULTS: Average translucency and color change values increased with increasing HAp coating concentration in HPPs. As a result of the data, statistically significant differences were observed in terms of the effect of the HAp coating on SBS of HPPs (p < 0.05). Failure modes were examined, and mixed failure mode was observed. CONCLUSION: HAp coating can contribute to the improvement of both the optical properties and bond strength of the HPPs to resin composite. CLINICAL SIGNIFICANCE: Adhesion and color problems of high performance polymers are still under discussion. In order to solve these problems, generally focused on surface modifications of these polymers, but the effect of the HAp coating has not been investigated.


Assuntos
Colagem Dentária , Durapatita , Cimentos de Resina/química , Teste de Materiais , Resistência ao Cisalhamento , Polímeros , Propriedades de Superfície , Resinas Compostas/química , Cetonas , Polietilenoglicóis , Microscopia Eletrônica de Varredura
4.
BMC Oral Health ; 22(1): 550, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36456927

RESUMO

BACKGROUND: In clinical settings, tooth preparation for prefabricated zirconia crowns (PZCs) in the primary dentition varies widely. However, knowledge about the biomechanical behavior of PZCs in various clinical settings is limited. This study was conducted to evaluate the biomechanical behavior of PZCs in different clinical settings using 3-dimensional finite element analysis. METHODS: 3-dimensional models of the PZC, cement, and tooth with six different conditions were simulated in primary molar teeth, incorporating cement thickness (100, 500, and 1000 µm) and cement type (resin-modified glass ionomer cement and resin cement). A total of 200 N of occlusal force was applied to the models, both vertically and obliquely as representative cases. A general linear model univariate analysis with partial eta-squared (ηp2) was performed to evaluate the relative effects of the variables. RESULTS: The overall stress of tooth was increased as the cement space increases under oblique loading. The von Mises stress values of the resin cements were significantly higher than those of the resin-modified glass ionomer cements for all cement thicknesses (p < .05). The effect size of the cement type (ηp2 = .519) was more dominant than the cement thickness (ηp2 = .132) in the cement layer. CONCLUSIONS: Within the limits of this study, cement type has a greater influence on the biomechanical behavior of PZCs than cement thickness.


Assuntos
Cimentos Dentários , Preparo do Dente , Humanos , Criança , Análise de Elementos Finitos , Cimentos de Ionômeros de Vidro , Materiais Dentários , Cimentos de Resina , Coroas
5.
Pol Przegl Chir ; 94(6): 46-53, 2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36468509

RESUMO

<b> Introduction:</b> Inguinal hernia repair is the most common operation worldwide. The essential factors in hernia repair have been the postoperative quality of life, early return to work, low recurrence rate, and chronic pain prevention. </br></br> <b>Aim:</b> The aim of this study was to compare the short- and long-term results of the self-adhesive mesh and the conventional polypropylene mesh in Lichtenstein repair. </br></br> <b> Material and methods:</b> A total of 100 male patients were randomized and operated on, 50 with the self-adhesive mesh (S group), 50 with the conventional polypropylene mesh (P group). Prospectively, the patients were followed for an average of 36 months. The two groups were compared for the duration of surgery, duration of hospital stay, duration of daily activity/resumption of work, postoperative pain, chronic pain, recurrence, wound infection, hematoma/seroma formation, and postoperative analgesic consumption. </br></br> <b>Results:</b> The study involved 39 patients in the P group and 37 patients in the S group who underwent inguinal hernia surgery. The P group had a longer mean operation time than the S group, and the difference between the two groups was statistically significant (45.1 ± 6.6 min vs. 28.8 ± 3.0 min, P = 0.0001). In recurrence, postoperative discomfort, chronic pain, length of hospital stay, daily activity/return to work, wound infection, hematoma/seroma, and postoperative analgesic use, there was no statistically significant difference between the two groups. </br></br> <b>Conclusion:</b> It was found that the self-adhesive mesh did not produce statistically significant advantages over the conventional polypropylene mesh, except for operative time, in the Lichtenstein repair.


Assuntos
Dor Crônica , Hérnia Inguinal , Humanos , Masculino , Estudos Prospectivos , Hérnia Inguinal/cirurgia , Polipropilenos/uso terapêutico , Cimentos de Resina , Adesivos , Seroma , Qualidade de Vida , Telas Cirúrgicas , Hematoma
6.
J Adhes Dent ; 24(1): 407-420, 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36346401

RESUMO

PURPOSE: To investigate the changes in the enamel bond performance of a two-step adhesive containing a primer derived from a universal adhesive in the early phase before 24 h and compare them to those of other adhesives. The Knoop hardness number (KHN) of the cured adhesive layers and resin composite was measured. MATERIALS AND METHODS: A new two-step adhesive using universal adhesive technology, G2-Bond Universal, was tested. Two conventional two-step adhesives, Clearfil SE Bond 2 and OptiBond eXTRa, and an established universal adhesive, Scotchbond Universal Plus Adhesive, were used as comparison materials. Twelve specimens per group were used to measure the shear bond strength (SBS) to bovine enamel in different etching modes. The bonded specimens were stored in distilled water at 37°C for 5 min or 1, 6, 12, or 24 h before SBS testing. The KHN of the adhesive layer and resin composite was determined after the same storage periods as for SBS testing. RESULTS: All adhesives exhibited increased SBS with prolonged storage periods, irrespective of the etching mode. The KHN of the adhesive layer and resin composite increased over time. CONCLUSIONS: There were strong positive correlations between the SBS and KHN of the adhesive layer and resin composite. Phosphoric acid pre-etching of enamel effectively increases enamel bond performance. The two-step adhesive G2-Bond Universal demonstrated significantly higher bond strength in the early phase than the other adhesives in self-etch mode.


Assuntos
Condicionamento Ácido do Dente , Colagem Dentária , Bovinos , Animais , Adesivos Dentinários/química , Cimentos Dentários/química , Teste de Materiais , Cimentos de Resina/química , Esmalte Dentário/química , Resistência ao Cisalhamento , Resinas Compostas
7.
J Adhes Dent ; 24(1): 395-406, 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36346400

RESUMO

PURPOSE: To evaluate the microtensile bond strength (µTBS) and silver nitrate uptake (SNU) of three universal adhesives used in etch-and-rinse (ER) and self-etch (SE) modes on dry, wet, and oversaturated dentin surfaces after 24 h and 1 year of water storage. The morphology of the hybrid layer (MHL) and the degree of conversion (DC) were also evaluated. MATERIALS AND METHODS: Human molars were divided into 36 groups according to combinations of the following variables: (i) universal adhesives (Ambar Universal APS [AMB], Prime&Bond Active [PBA], Scotchbond Universal Adhesive [SBU]), (ii) adhesive strategies (ER or SE), (iii) moisture level (dry, wet, or oversaturated dentin surface), and (iv) storage time (24 h or 1 year). After restoration, the specimens were sectioned into resin-dentin sticks and tested for µTBS and SNU according to storage time. For MHL, the specimens were sectioned and evaluated after 24 h using SEM. DC was evaluated using FTIR. ANOVA and Tukey's test were used for statistical analyses (5%). RESULTS: When 24-h vs 1-year data were compared, there was a significant decrease in µTBS and an increase in SNU values for the majority of experimental groups (p < 0.0001). On dry (ER) and oversaturated (ER and SE) dentin, AMB showed higher µTBS than did PBA (p < 0.00001). No significant decrease in µTBS was observed when universal adhesives were applied in the SE mode to dry dentin (p > 0.05). Regarding SNU, at all moisture levels, AMB showed lower SNU values than SBU (p < 0.001). Regarding MHL, SBU showed several imperfections when applied to oversaturated dentin in comparison with AMB and PBA. Regarding DC, when dentin was kept dry or was oversaturated, AMB showed a higher DC than PBA (p < 0.0001). CONCLUSION: The behavior of the different universal adhesives evaluated did not vary when applied to wet or dry dentin. However, the results with oversaturated dentin were dependent on the universal adhesive. Independent of the moisture level and the universal adhesive evaluated, significant degradation of the bonding properties occurred after 1 year of water storage, with the exception of universal adhesives applied to dry dentin in the SE strategy.


Assuntos
Colagem Dentária , Infiltração Dentária , Humanos , Adesivos Dentinários/química , Resinas Compostas/química , Cimentos Dentários/química , Dentina , Resistência à Tração , Teste de Materiais , Cimentos de Resina/química , Água/química , Adesivos
8.
J Adhes Dent ; 24(1): 435-443, 2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36440831

RESUMO

PURPOSE: This study investigated the effects of mechanical and chemical pretreatment of polyetherketoneketone (PEKK) on shear bond strength (SBS) to root dentin using two types of resin cement. MATERIALS AND METHODS: A total of 100 PEKK specimens were prepared and polished. Sixty specimens were mechanically treated by sandblasting (50-µm Al2O3 for 10 s at 0.2-0.25 MPa), and the remaining 40 were untreated. Self-adhesive resin cement and conventional resin cement were used. PEKK specimens bonded to root dentin using self-adhesive resin cement were classified into three groups by pretreatment method: (1) untreated PEKK, (2) mechanical pretreatment (sandblasted PEKK), and (3) both mechanical and chemical pretreatment (PEKK sandblasting as well as application of Scotchbond Universal; 3M Oral Care). Conventional resin cement was pretreated following the same steps (1-3) as those followed for self-adhesive specimens. Each group included 10 specimens. PEKK specimens after surface treatments were examined using SEM. SBS tests were performed using a universal testing machine, and data were statistically analyzed using one-way ANOVA and Tukey's multiple comparison test (p < 0.05). RESULTS: No significant difference was observed between cements with and without sandblasting. However, self-adhesive specimens with both mechanical and chemical pretreatments demonstrated higher SBS than other cements with or without pretreatment. CONCLUSION: Mechanical pretreatment by sandblasting did not improve the PEKK-root dentin SBS. However, combined mechanical (sandblasting) and chemical pretreatment (ScotchBond Universal) significantly improved the SBS between the PEKK and root dentin.


Assuntos
Colagem Dentária , Cimentos de Resina , Cimentos de Resina/química , Cimentos Dentários/química , Análise do Estresse Dentário , Dentina
9.
Int J Mol Sci ; 23(21)2022 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-36361575

RESUMO

Glass-ceramic spray deposition (GCSD) is a novel technique for coating lithium disilicate (LD) glass-ceramics onto zirconia through simple tempering steps. GCSD has been proven to improve the bonding of zirconia to resin cement, but the effect of etching time on GCSD and the long-term durability of the bond achieved remain unknown. The effects of air abrasion with aluminum particles (ABB) and air abrasion (GAB) or etching with 5.0% hydrogen fluoride (HF) for 20, 60, 90, and 120 s (G20, G60, G90, and G120) on the resin cement-zirconia bond were studied. LD was included as a control (LDG). The microstructure, sub-micron roughness, wettability, and phase changes of samples were analyzed. After resin cement was bonded to zirconia, half of the samples were subjected to thermocycling (5000 cycles at 5-55 °C). The bond strengths of the samples were determined in shear bond strength (SBS) tests (n = 10 per group). An LD structure can be formed on zirconia after GCSD and proper etching processes, which result in high roughness and a hydrophilic nature. GCSD and HF etching significantly improved SBS, with G90 and G120 samples with pre- or post-thermocycling exhibiting SBS values comparable to those of LDG (p > 0.760). The surface characteristics of the LD layer are influenced by the etching time and affect the SBS of the bond of zirconia to resin cement. HF etching for 90-120 s after GCSD results in zirconia with SBS and bond durability comparable to LD.


Assuntos
Colagem Dentária , Zircônio , Zircônio/química , Cimentos de Resina/química , Adesivos , Teste de Materiais , Propriedades de Superfície , Cerâmica/química , Resistência ao Cisalhamento , Ácido Fluorídrico/química , Tecnologia
10.
Oper Dent ; 47(6): E253-E263, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36322381

RESUMO

PURPOSE: To evaluate the effect of application time and viscosity of meta-phosphoric acid (MPA) and ortho-phosphoric acid (OPA) on the push-out resin-dentin bond strength (PBS) and nanoleakage (NL) at the adhesive-root dentin interface. METHODS AND MATERIALS: Ninety-six roots of premolars were endodontically prepared and randomly assigned into groups according to the (i) acid (OPA and MPA), (ii) viscosity (gel and liquid), and (iii) application time (7 and 15 seconds). Fiber posts were cemented to the roots, which were then transversally sectioned into serial slices. The slices (cervical, medium, and apical) were subjected to PBS or NL. Analysis of the dentin etching pattern was performed using scanning electron microscopy (SEM). The PBS (MPa) and NL (%) data were subjected to three-way repeated-measures analysis of variance (ANOVA) and Tukey's test (α=0.05). RESULTS: The cross-product interaction was significant for both PBS and NL (p<0.001). No significant difference in the PBS was observed with the use of OPA compared to MPA (p>0.05). Higher PBS values were observed in the groups etched for 15 seconds compared to 7 seconds, regardless of the acid, viscosity, or root third (p<0.05). Lower NL was observed for MPA etching when compared to OPA etching (p<0.05), and these values were not affected by increasing the application time or acid viscosity (p>0.05). A more pronounced etching pattern was observed with OPA than MPA regardless of the acid viscosity. CONCLUSION: The use of 40% meta-phosphoric acid promoted adequate bond strength without increasing dentin demineralization or void spaces in the hybrid layer.


Assuntos
Colagem Dentária , Técnica para Retentor Intrarradicular , Dentina , Viscosidade , Ácidos Fosfóricos/farmacologia , Teste de Materiais , Cimentos de Resina/química , Adesivos Dentinários/química , Cavidade Pulpar
11.
Oper Dent ; 47(6): E264-E272, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36322401

RESUMO

OBJECTIVES: To evaluate the bond strength of a resin luting agent to a lithium disilicate glass-ceramic after the use of different fit-checking materials and cleaning protocols. METHODS AND MATERIALS: Two hundred and forty-two (242) ceramic specimens were etched with 5% hydrofluoric acid for 20 seconds and distributed into 22 groups (n=10), in total. Four (4) groups were created based on fit-checking material and that had no following cleaning protocol: no fit-checking material used (control group); articulating paper; articulating spray; and fit-checker liquid. For each fit-checking material (3), 6 cleaning protocols were tested creating an additional 18 groups (n=10): air/water spray; 70% alcohol (ethanol); acetone; 35% phosphoric acid; 5% hydrofluoric acid; and a commercially available cleaning paste (Ivoclean, Ivoclar Vivadent). Silane and bonding resin were applied to all ceramic surfaces. Resin luting agent cylinders (1 mm in diameter) were created using silicone matrices, light-cured, and specimens were stored in deionized water at 37°C for 24 hours. Microshear bond strength test (µSBS) was performed on a universal testing machine (DL 500, EMIC) at a crosshead speed of 1 mm/min until failure. Results were statistically analyzed using ANOVA and Tukey's test (α=0.05). RESULTS: Articulating paper and fit-checker liquid, when not properly removed, negatively affected the bond strength (p<0.05). None of the tested cleaning protocols were effective for articulating paper (p<0.05). There was no significant difference in bond strength after the cleaning protocols between articulating spray and fit-checker liquid when compared to the control group (no contamination) (p>0.05). CONCLUSION: The cleaning protocols tested can effectively restore the bond strength of resin luting agents to lithium disilicate ceramics that were exposed to articulating spray or fit-checker liquid. The use of articulating paper is not recommended for fit-checking indirect lithium disilicate restorations.


Assuntos
Colagem Dentária , Ácido Fluorídrico , Ácido Fluorídrico/química , Colagem Dentária/métodos , Análise do Estresse Dentário , Teste de Materiais , Porcelana Dentária/uso terapêutico , Porcelana Dentária/química , Cerâmica/uso terapêutico , Cerâmica/química , Cimentos de Resina/uso terapêutico , Cimentos de Resina/química , Silanos/química , Água/química , Propriedades de Superfície
12.
Med Sci Monit Basic Res ; 28: e937893, 2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36394828

RESUMO

BACKGROUND The aim of this study was to evaluate the antimicrobial effectiveness of dental cement materials for the prevention of bacterial growth, which can cause failure of fixed cementation. MATERIAL AND METHODS We developed an agar diffusion disk test in-house to evaluate the antibacterial properties of 3 commercially available dental cement materials (Ketac, Harvard FLB, and Panavia SA Universal Dual Resin cements) compared with a negative control. The materials were tested for the inhibition against Streptococcus mutans (ATCC 10449), Streptoccocus salivarius (ATCC 25975), Enterococcus faecalis (ATCC 29212), and Lactobacilus acidophilus (ATCC 4356). The antimicrobial effectiveness of materials was expressed as the diameters of the inhibition zones around the disk. RESULTS Overall, 240 specimens were tested. All cement materials showed antimicrobial effectiveness. Different microbial strains reacted differently to the different dental cements (all P.


Assuntos
Anti-Infecciosos , Anti-Infecciosos/farmacologia , Antibacterianos/farmacologia , Streptococcus mutans , Cimentos de Resina/farmacologia
13.
Dent Mater ; 38(12): 1942-1946, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36347654

RESUMO

OBJECTIVES: The aim was to investigate shear bond strengths and failure modes of four self-etch bonding agents to bovine dentin and enamel and to compare evaluation of data sets with or without exclusion of cohesive failure specimens. METHODS: Composite-cylinders were bonded perpendicularly to bovine dentin and enamel surfaces. Shear-strengths were measured 24 h post-bonding of: Scotchbond Universal® (SBU, 3 M), OptiBond™ XTR (OBXTR, Kerr), OptiBond™ universal (OBU, KaVo-Kerr) and Prime & Bond active® (PBA, Dentsply-Sirona). Analysis of overall data was made via a linear mixed-model. This was repeated after exclusion of specimens associated with cohesive failures. RESULTS: When both adhesive and cohesive failures were considered, OBU and OBXTR showed comparable dentin and enamel bond strengths, whereas lower strengths were found on enamel for SBU (p < 0.001) and PBA (p = 0.015). For OBXTR higher shear strengths were measured for specimens associated with cohesive failures. When cohesive failures were excluded, the majority of shear bond strengths of adhesive failure specimens were only slightly different from overall results. However, uniquely with OBXTR dramatically lower shear bond strengths were found for dentin substrate. SIGNIFICANCE: After exclusion of cases with cohesive failures OBXTR adhesive fell behind other materials in the sequence of average shear strengths. This did not reflect the actual performance of the material. Therefore, in statistical analysis we do not recommend exclusion of data based on a specific fracture mode.


Assuntos
Colagem Dentária , Adesivos Dentinários , Bovinos , Animais , Adesivos Dentinários/química , Colagem Dentária/métodos , Dentina/química , Cimentos Dentários/química , Teste de Materiais , Cimentos de Resina/química , Resistência ao Cisalhamento , Resinas Compostas/química
14.
Dent Mater ; 38(12): 2003-2013, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36424207

RESUMO

OBJECTIVE: To characterize the effect of pigmentation techniques on the fatigue behavior of a 4YSZ ceramic adhesively luted onto dentin analog (glass fiber-reinforced epoxy resin). METHODS: 4YSZ ceramic discs (Ø= 10 mm, 1 mm thickness) were allocated into 5 groups: Ctrl - unshaded (IPS e.max ZirCAD MT BL); Manuf - shaded by the manufacturer (IPS e.max ZirCAD MT A2); Brush - unshaded pigmented, pre-sintering, using a brush; Stain - unshaded pigmented, post-sintering, during glaze application; Brush+Stain - combination of both techniques. Color assessments ensured the same perceived color (Vita Classical A2). Dentin analog discs (Ø= 10 mm, 2.5 mm thickness) were obtained, paired with the 4YSZ discs, and adhesively luted using a resin cement. Cyclic fatigue testing (n = 15) was run (20 Hz; 10,000 cycles/step, initial load 200 N; step-size 100 N up to 700 N; then 50 N until specimen failure). Fractographic, roughness and topography analyses were performed. RESULTS: No statistical (p > 0.05) detrimental influence were observed for fatigue outcomes (Ctrl = Manuf = Brush = Stain = Brush+Stain). However, the Brush+Stain technique induced inferior statistical (p < 0.05) fatigue performance compared to Stain. All failures were radial cracks with origin at the ceramic intaglio surface. The staining technique triggered statistically higher roughness (p < 0.05). Uniformly sized zirconia crystals were seen in the Ctrl, Manuf and Brush groups, and a smooth vitreous surface with encrusted pigments in the Stain and Brush+Stain groups. SIGNIFICANCE: Pigmentation techniques (Vita Classical A2 shade) have no detrimental effect on the mechanical fatigue properties of 4YSZ ceramic adhesively luted onto dentin analog.


Assuntos
Cerâmica , Pigmentação , Corantes , Cimentos de Resina , Dentina
15.
Dent Mater ; 38(12): 2073-2083, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36443106

RESUMO

OBJECTIVES: This study investigated potential variations in polymerisation of light- and dual-cured (LC and DC) resin cements photoactivated through four CAD/CAM restorative materials as a function of substrate thickness. METHODS: Four CAD/CAM materials [two resin composites CeraSmart (CS) and Grandio Blocs (GB); a polymer infiltrated ceramic Vita Enamic (VE) and a feldspathic ceramic Vita Mark II (VM)], with five thicknesses (0.5, 1, 1.5, 2, and 2.5 mm) were prepared and their optical characteristics measured. 1 mm discs of LC and DC resin cement (Variolink® Esthetic, Ivoclar AG) were photoactivated through each specimen thickness. After 1 h post-cure, polymerisation efficiency was determined by degree of conversion (DC%) and Martens hardness (HM). Interactions between materials, thicknesses and properties were analysed by linear regressions, two-way ANOVA and one-way ANOVA followed by post hoc multiple comparisons (α = 0.05). RESULTS: All substrates of 0.5- and 1.0-mm thickness transmitted sufficiently high peak irradiances at around 455 nm: (It = 588-819 mW/cm2) with translucency parameter TP = 21.14 - 10.7; ranked: CS> GB = VM> VE. However, increasing the substrate thickness (1.5-2.5 mm) reduced energy delivery to the luting cements (4 - 2.8 J/cm2). Consequently, as their thicknesses increased beyond 1.5 mm, HM of the cement discs differed significantly between the substrates. But there were only slight reduction of DC% in LC cements and DC cement discs were not affected. SIGNIFICANCE: Photoactivating light-cured Ivocerin™ containing cement through feldspathic ceramics and polymer-infiltrated ceramics achieved greater early hardness results than dual-cured type, irrespective of substrate thickness (0.5 - 2.5 mm). However, only 0.5 and 1 mm-thick resin composites showed similar outcome (LC>DC). Therefore, for cases requiring early hardness development, appropriate cement selection for each substrate material is recommended.


Assuntos
Estética Dentária , Cimentos de Resina , Desenho Assistido por Computador , Polimerização , Cimentos de Ionômeros de Vidro , Cimentos Dentários , Materiais Dentários , Cimentos Ósseos , Polímeros
17.
Medicina (Kaunas) ; 58(10)2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36295629

RESUMO

Background and Objectives: There is no consensus regarding the surface treatment method for achieving optimal bonding strength between zirconia and resin cements. We evaluated the effect of hot-etching with 9% hydrofluoric acid (HF) gel using the Zirconia Etchant Cloud System on zirconia surfaces and the consequent shear bond strength (SBS) of different resin cements to such surface-treated zirconia ceramics. Materials and Methods: Forty-five zirconia specimens were randomly assigned to surface-treatment groups (n = 15/group): no treatment (control, CT); sandblasting with 110-µm Al2O3 at an air pressure of 1 bar for 10 s (SB); hot-etching with 9% HF gel (HE). Post-treatment, specimens were examined using scanning electron microscopy (SEM) and surface roughness (SR) analysis. After treatment, self-adhesive resin cements (Maxcem Elite, MAZIC Cem, RelyX U200, 3M ESPE: Maplewood, MN, USA) were bonded to zirconia specimens, which were stored in distilled water at 37 °C for 24 h. All specimens were then subjected to SBS testing, using a universal testing machine, until failure. Data were analyzed using one-way analysis of variance and Tukey's post hoc test (α = 0.05). Results: In the SEM images, roughness was greater in SB than in HE specimens. Ra and Rt values were highest in SB, followed by HE, and CT specimens. HE specimens showed significantly higher SBS values than CT or SB specimens (p < 0.05). MAZIC Cem cement, with 10-methacryloyloxydcyl dihydrogen phosphate yielded the highest SBS values. Conclusions: Hot-etching with 9% HF gel in a safe shell formed uniformly small, defined holes on the zirconia surface and achieved significantly higher SBS values than sandblasting (p < 0.05). Zirconia prostheses can be bonded micromechanically with resin cement, without the deterioration of properties due to t-m transformation, using chemical acid etching with the Zirconia Etchant Cloud System.


Assuntos
Ácido Fluorídrico , Cimentos de Resina , Humanos , Cimentos de Resina/química , Ácido Fluorídrico/química , Teste de Materiais , Propriedades de Superfície , Cerâmica , Água/química , Fosfatos
18.
J Adhes Dent ; 24(1): 367-374, 2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36255852

RESUMO

PURPOSE: To evaluate the effect of different pretreatment protocols and adhesives on the shear bond strength and surface morphology of aprismatic enamel. MATERIALS AND METHODS: Human maxillary incisors (N = 120) were assigned to five different groups according to pretreatment: 1) no treatment; 2) glycine; 3) sodium bicarbonate; 4) Al2O3 and 5) extra-fine bur. Then the teeth were divided into three subgroups, according to the adhesive applied: 3-step etch-and-rinse (ER), universal adhesive in ER mode, and universal adhesive in self-etch (SE) mode. Shear bond strength (SBS) testing was performed with a universal testing machine. For SEM observation, fifteen human molars were collected and analyzed after pretreatment with/without etching with 37% H3PO4 for 30s. RESULTS: Al2O3 showed higher SBS than all other groups considered. Comparable SBS values were obtained for other pretreatments. Universal adhesive in E&R mode performed better than did 3-step E&R and universal adhesive in SE mode. SEM images showed visible differences in enamel surface roughness. CONCLUSIONS: Airborne-particle abrasion with Al2O3 followed by etching with H3PO4 increased SBS on aprismatic enamel. The combination of airborne-particle abrasion with alumina powder followed by 15 s of H3PO4 etching and application of a universal adhesive in E&R mode proved to be the most effective adhesive protocol.


Assuntos
Condicionamento Ácido do Dente , Colagem Dentária , Humanos , Condicionamento Ácido do Dente/métodos , Colagem Dentária/métodos , Cimentos Dentários/química , Bicarbonato de Sódio , Pós , Teste de Materiais , Esmalte Dentário , Resistência ao Cisalhamento , Óxido de Alumínio , Glicina , Cimentos de Resina/química , Adesivos Dentinários
19.
J Adhes Dent ; 24(1): 375-384, 2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36255853

RESUMO

PURPOSE: The purpose of this study was to assess the effect of aging and alumina-particle air abrasion at different pressures on the bond strength of two luting composites to a translucent 3Y-TZP zirconia. MATERIALS AND METHODS: Half of the 192 disk-shaped zirconia specimens were aged in an autoclave (group A) for 20 h (134°C, 2 bar), and the other half was not aged (group N). For each group, a different surface treatment was applied: as-sintered (group SIN), alumina-particle air abrasion either at 1 bar (group 1B) or at 2.5 bar (group 2.5B). Disks were bonded to Plexiglas tubes filled with composite resin using a phosphate monomer-based luting composite (group SA) or with a separate phosphate monomer containing primer before using a phosphate-monomer-free luting composite (group V5). All specimens were subjected to tensile bond strength testing (TBS) before and after thermocycling. RESULTS: There were no statistically significant differences caused by autoclave aging for the test groups before thermocycling, except for the A-SIN-SA group, where the TBS decreased significantly. The variation of the aluminaparticle air abrasion pressure showed no statistically significant effect, except in the N-1B-V5 group, where TBS was significantly lower than N-2.5B-V5. After thermocycling, the TBS of most groups decreased significantly. Specimens of the primer group, which were abraded at 1 bar, showed a significant decrease in TBS in comparison with alumina-particle air abrasion at 2.5 bar. CONCLUSION: Twenty hours of autoclave aging had almost no influence on the bond strength of the test groups. For the primer/resin bonding system, higher pressure during alumina-particle air abrasion might help obtain a higher and more durable bond strength to zirconia.


Assuntos
Colagem Dentária , Cimentos de Resina , Cimentos de Resina/química , Abrasão Dental por Ar , Polimetil Metacrilato , Análise do Estresse Dentário , Teste de Materiais , Propriedades de Superfície , Zircônio/química , Resinas Compostas , Óxido de Alumínio/química , Fosfatos
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