Caracterização de superfície, adesiva e mecânica de uma zircônia parcialmente estabilizada por ítria em função da partícula ou do momento do jateamento

Pós-graduação em Reabilitação Oral - FOAR

Effect of surface treatment on the bond strength between yttria partially stabilized zirconia ceramics and resin cement

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of Decomposition Procedure to Determine Ba, Co, Cr, Cu, Ni, Mn, V, and Zn Total Content in Soil Samples

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação do tempo e da concentração do condicionamento com ácido fluorídrico sobre a resistência de união entre cerâmica e cimento resinoso

The aim of this study was to verify through microtensile test the influence of time and concentration of surface conditioning with hydrofluoric acid and its interference in the adhesion of dual resin cement to porcelain.We used 32 bodies of glass-ceramic lithium disilicate system IPS e.max Press LT with dimensions of 6mm thick, 8 mm in length and 8 mm in length, which will be molded to obtain composite resin blocks corresponding to blocks ceramics. Ceramic and resin blocks were divided into 16 groups (n = 4) and numbered according to the concentration of hydrofluoric acid (2.5%, 5%, 7.5% and 10%) and conditioning time (20 seconds, 40 seconds, 1 minute and 2 minutes). The blocks were cleaned in ultrasonic apparatus with distilled water and dried with compressed air, subjected to acid etching and air-jet washed with water, dried with compressed air and received application of silane agent Monobond-S, followed by adhesive Excite ( Ivoclar Vivaden). Each ceramic block was bonded to the corresponding block of resin through the resin cement Multilink Automix. The specimens were cut to obtain nine micro samples for each set of ceramic-resin with 1 mm X 1 mm X 12 mm in length, which were submitted to microtensile test. The results were analyzed with descriptive statistics and analysis of variance with significance level of 5%, revealing that there were statistically significant (p = 0.000001 <0.05). From the Tukey test can be concluded that etching with hydrofluoric acid and 2.5% for 120 seconds gave the best bond strength, however, no statistical difference between the conditioning with the same acid in the concentration of 5.0% for 20 to 40 seconds

Resistência de união de cimentos resinosos em superfície de cerâmica de Y-TZP após aplicação de filme vitrocerâmico

Pós-graduação em Odontologia Restauradora - ICT

Efeito de protocolos de cimentação na carga de fratura para uma cerâmica de dissilicato de lítio

Pós-graduação em Odontologia Restauradora - ICT

Efeito da limpeza pós-condicionamento e do tratamento térmico do silano na resistência de união de um cimento resinoso à cerâmica

Pós-graduação em Odontologia - FOA

Caracterização de uma cerâmica 3Y-TZP e avaliação do efeito de tratamentos de superfície na adesão da cerâmica ao glaze ou cimento resinoso

Pós-graduação em Odontologia Restauradora - ICT

Confiabilidade de coroas com infraestrutura em zircônia sob fadiga deslizante: efeito do tipo de tratamento interno para cimentação

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Repair of composites: Effect of laser and different surface treatments

Objectives: This study investigated the repairs of resin composite restorations after using different surface treatments.Design: Eighty four truncated cones of Filtek Z350 were prepared and thermo-cycled (20,000 cycles). Surfaces were roughened with diamond bur and etched with 37% phosphoric acid. Those cones were divided into 7 groups (N=12): 1) Prime&Bond 2.1; 2) aluminum oxide sandblasting+Prime&Bond 2.1; 3) Er:YAG laser treatment+Prime&Bond 2.1; 4) 9.6% hydrofluoric acid for 2 min-Fsilane coupling agent.; 5) silane coupling agent; 6) auto-polymerized acrylic monomer+Prime&Bond 2.1; 7) Adper Scothbond SE. Teflon device was used to fabricate inverted truncated cones of repair composite over the surface-treated. The bonded specimens were stressed to failure under tension. The data were analyzed with oneway ANOVA and Tukey tests.Results: Mean repair strengths (SD, in MPa) were, Group-2: 18.8a; Group-1: 18.7a; Group-6: 13.4ab; Group-7: 9.5bc; Group-3: 7.5bcd; Group-4: 5.2cd; Group-5: 2.6d.Conclusions: The use of diamond bur and a conventional adhesive and the use of aluminum oxide sandblasting prior to adhesive provided a simple and cost-effective solutions to composite repair. Er:YAG laser, silane alone, 9.6% hydrofluoric acid plus silane or a self-etching adhesive results in inferior composite repair strengths. (C) 2015 Elsevier Ltd. All rights reserved.

Surface characterization of lithium disilicate ceramic after nonthermal plasma treatment

Statement of problem. Surface transformation with nonthermal plasma may be a suitable treatment for dental ceramics, because it does not affect the physical properties of the ceramic material.Purpose. The purpose of this study was to characterize the chemical composition of lithium disilicate ceramic and evaluate the surface of this material after nonthermal plasma treatment.Material and methods. A total of 21 specimens of lithium disilicate (10 mm in diameter and 3 mm thick) were fabricated and randomly divided into 3 groups (n=7) according to surface treatment. The control group was not subjected to any treatment except surface polishing with abrasive paper. In the hydrofluoric acid group, the specimens were subjected to hydrofluoric acid gel before silane application. Specimens in the nonthermal plasma group were subjected to the nonthermal plasma treatment. The contact angle was measured to calculate surface energy. In addition, superficial roughness was measured and was examined with scanning electron microscopy, and the chemical composition was characterized with energy-dispersive spectroscopy analysis. The results were analyzed with ANOVA and the Tukey honestly significant difference test (alpha=.05).Results. The water contact angle was decreased to 0 degrees after nonthermal plasma treatment. No significant difference in surface roughness was observed between the control and nonthermal plasma groups. Scanning electron microscopy and energy-dispersive spectroscopy images indicated higher amounts of oxygen (O) and silicon (Si) and a considerable reduction in carbon (C) in the specimens after nonthermal plasma treatment.Conclusions. Nonthermal plasma treatment can transform the characteristics of a ceramic surface without affecting its surface roughness. A reduction in C levels and an increase in 0 and Si levels were observed with the energy-dispersive spectroscopy analysis, indicating that the deposition of the thin silica film was efficient.

Heat treatment of pre-hydrolyzed silane increases adhesion of phosphate monomer-based resin cement to glass ceramic

This study evaluated the influence of different forms of heat treatment on a pre-hydrolyzed silane to improve the adhesion of phosphate monomer-based (MDP) resin cement to glass ceramic. Resin and feldspathic ceramic blocks (n=48, n=6 for bond test, n=2 for microscopy) were randomly divided into 6 groups and subject to surface treatments: G1: Hydrofluoric acid (HF) 9.6% for 20 s + Silane + MDP resin cement (Panavia F); G2: HF 9.6% for 20 s + Silane + Heat Treatment (oven) + Panavia F; G3: Silane + Heat Treatment (oven) + Panavia F; G4: HF 9.6% for 20 s + Silane + Heat Treatment (hot air) + Panavia F; G5: Silane + Heat Treatment (hot air) + Panavia F; G6: Silane + Panavia F. Microtensile bond strength (MTBS) test was performed using a universal testing machine (1 mm/min). After debonding, the substrate and adherent surfaces were analyzed using stereomicroscope and scanning electron microscope (SEM) to categorize the failure types. Data were analyzed statistically using two-way test ANOVA and Tukey's test (=0.05). Heat treatment of the silane containing MDP, with prior etching with HF (G2: 13.15 ± 0.89a; G4: 12.58 ± 1.03a) presented significantly higher bond strength values than the control group (G1: 9.16 ± 0.64b). The groups without prior etching (G3: 10.47 ± 0.70b; G5: 9.47 ± 0.32b) showed statistically similar bond strength values between them and the control group (G1). The silane application without prior etching and heat treatment resulted in the lowest mean bond strength (G6: 8.05 ± 0.37c). SEM analysis showed predominantly adhesive failures and EDS analysis showed common elements of spectra (Si, Na, Al, K, O, C) characterizing the microstructure of the glass-ceramic studied. Heat treatment of the pre-hydrolyzed silane containing MDP in an oven at 100 °C for 2 min or with hot air application at 50 ± 5 ºC for 1 min, was effective in increasing the bond strength values between the ceramic and resin cement containing MDP.

Efeitos de lasers de alta potência na superfície de cerâmicas vítreas de dissilicato de lítio e sua resistência de união à dentina humana

Pós-graduação em Odontologia Restauradora - ICT

Efeitos de lasers de alta potência na superfície de cerâmicas vítreas de dissilicato de lítio e sua resistência de união à dentina humana

Pós-graduação em Odontologia Restauradora - ICT

Shear bond strength of repairs in porcelain conditioned with laser

The aim of this study was to evaluate the shear bond strength of repairs in porcelain conditioned with laser. Sixty porcelain discs were made and six groups were formed (n = 10): G1: conditioning with laser with potency 760 mW; G2: conditioning with laser with potency 760 mW and application of 37% phosphoric acid for 15 s; G3: conditioning with laser with potency 900 mW; G4: conditioning with laser with potency 900 mW and application of 37% phosphoric acid for 15 s; G5: application of 37% phosphoric acid for 15 s (group control) and G6: application of 10% hydrofluoric acid for 2 min. The composite resin was insert of incremental layers at the porcelain surface aided with a metal matrix, and photoactivation for 20 s each increment. The specimens were submitted to a thermal cycling by 1000 cycles of 30 s in each bath with temperature between 5 and 55 degrees C. After the thermal cycling, specimens were submitted to the shear bond strength. The results were evaluated statistically through analysis of variance and Tukey's tests with 5% significance. The averages and standard deviation founded were: G1, 11.25 (+/- 3.10); G2, 12.32 (+/- 2.65); G3, 14.02 (+/- 2.38); G4, 13.44 (+/- 2,07); G5, 9.91 (-/+ 2,18); G6, 12.74 (+/- 2.67). The results showed that the femtosecond laser produced a shear bond strength of repairs in porcelain equal to the hydrofluoric acid and significantly superior to the use of phosphoric acid. Microsc. Res. Tech., 2012. (C) 2012 Wiley Periodicals, Inc.