Effect of Plasma and Fiber Position on Flexural Properties of a Polyethylene Fiber-Reinforced Composite.

The aim of this study was to evaluate the effect of plasma treatment using argon and oxygen gases, combined with fiber position on flexural properties of a fiber-reinforced composite. Eleven groups were evaluated, a non-reinforced control group and 10 groups reinforced with InFibra, a woven polyethylene fiber, varying according to the plasma treatment and fiber position. The samples were prepared using a stainless steel two-piece matrix. The three point bending test was performed in an EMIC testing machine. Flexural strength (FS) and flexural deflection (FD) were calculated from initial (IF) and final (FF) failure. Data were evaluated statistically using Kruskal-Wallis and Mann-Whitney tests (p<0.05). For IF, in all groups with fibers placed on the base, the FS and FD values were significantly higher than those positioned away from the base. The highest value of FS was obtained in the group treated with O 3 min (296.2 MPa) and the highest value of FD was obtained in the group treated with 1 min (0.109 mm). For FF the FS and FD values obtained for the groups with fibers positioned away from the base were similar or higher than those placed on the base. The highest FS value was obtained in the group treated with 1 min (317.5 MPa) and the highest FD value was obtained in the group treated with O 3 min (0.177 mm). Plasma treatment influenced FS and FD. Fiber position and plasma treatment affected the flexural properties of a fiber-reinforced composite.

Effects of plasma on polyethylene fiber surface for prosthodontic application

ABSTRACT Plasma technology has the potential to improve the adherence of fibers to polymeric matrices, and there are prospects for its application in dentistry to reinforce the dental particulate composite. Objectives This study aimed to investigate the effect of oxygen or argon plasma treatment on polyethylene fibers. Material and Methods Connect, Construct, InFibra, and InFibra treated with oxygen or argon plasma were topographically evaluated by scanning electron microscopy (SEM), and chemically by X-ray photoelectron spectroscopy (XPS). For bending analysis, one indirect composite (Signum) was reinforced with polyethylene fiber (Connect, Construct, or InFibra). The InFibra fiber was subjected to three different treatments: (1) single application of silane, (2) oxygen or argon plasma for 1 or 3 min, (3) oxygen or argon plasma and subsequent application of silane. The samples (25x2x2 mm), 6 unreinforced and 60 reinforced with fibers, were subjected to three-point loading tests to obtain their flexural strength and deflection. The results were statistically analyzed with ANOVA and the Bonferroni correction for multiple comparison tests. Results SEM analysis showed that oxygen and argon plasma treatments promote roughness on the polyethylene fiber surface. X-ray photoelectron spectroscopy (XPS) analysis shows that both plasmas were effective in incorporating oxygenated functional groups. Argon or oxygen plasma treatment affected the flexural strength and deflection of a fiber reinforced composite. The application of silane does not promote an increase in the flexural strength of the reinforced composites. Conclusions Oxygen and argon plasma treatments were effective in incorporating oxygenated functional groups and surface roughness. The highest strength values were obtained in the group reinforced with polyethylene fibers treated with oxygen plasma for 3 min.

Effect of Plasma and Fiber Position on Flexural Properties of a Polyethylene Fiber-Reinforced Composite

Abstract: The aim of this study was to evaluate the effect of plasma treatment using argon and oxygen gases, combined with fiber position on flexural properties of a fiber-reinforced composite. Eleven groups were evaluated, a non-reinforced control group and 10 groups reinforced with InFibra, a woven polyethylene fiber, varying according to the plasma treatment and fiber position. The samples were prepared using a stainless steel two-piece matrix. The three point bending test was performed in an EMIC testing machine. Flexural strength (FS) and flexural deflection (FD) were calculated from initial (IF) and final (FF) failure. Data were evaluated statistically using Kruskal-Wallis and Mann-Whitney tests (p<0.05). For IF, in all groups with fibers placed on the base, the FS and FD values were significantly higher than those positioned away from the base. The highest value of FS was obtained in the group treated with O 3 min (296.2 MPa) and the highest value of FD was obtained in the group treated with 1 min (0.109 mm). For FF the FS and FD values obtained for the groups with fibers positioned away from the base were similar or higher than those placed on the base. The highest FS value was obtained in the group treated with 1 min (317.5 MPa) and the highest FD value was obtained in the group treated with O 3 min (0.177 mm). Plasma treatment influenced FS and FD. Fiber position and plasma treatment affected the flexural properties of a fiber-reinforced composite.

Resumo O objetivo deste estudo foi avaliar o efeito do tratamento de plasma, utilizando os gases argônio e oxigênio, associado à posição da fibra, nas propriedades mecânicas de um compósito reforçado por fibra. Onze grupos foram avaliados, um grupo controle, sem reforço, e 10 grupos reforçados com Infibra, variando de acordo com o tratamento de plasma e a posição das fibra. As amostras foram preparadas utilizando uma matriz bipartida de aço inoxidável. O teste de flexão de três pontos foi realizado em uma máquina de ensaios EMIC. A resistência à flexão (FS) e deflexão (FD) foram calculados em relação à falha inicial (IF) e final (FF). Os dados foram avaliados estatisticamente pelos testes de Mann-Whitney e Kruskal-Wallis (p<0,05). Para IF, nas fibras posicionadas na base, os valores de FS e FD foram significativamente maiores do que quando as fibras foram afastadas da base em todos os grupos. O maior valor de FS foi obtido no grupo tratado com O 3 min (296,2 MPa) e o maior valor de FD foi obtido no grupo tratado com O 1 min (0,109 mm). Para FF, os valores de FS e FD para os grupos com fibras afastadas da base foram semelhantes ou superiores aos daqueles com fibras na base. O maior valor de FS foi obtido no grupo tratado com O 1 min (317,5 MPa) e o maior valor de FD foi obtido no grupo tratado com O 3 min (0,177 mm). O tratamento de plasma influenciou o FS e o FD. A posição de fibras, assim como o tratamento de plasma, afetaram as propriedades de flexão de um compósito reforçado com fibra.

Effects of plasma on polyethylene fiber surface for prosthodontic application.

UNLABELLED: Plasma technology has the potential to improve the adherence of fibers to polymeric matrices, and there are prospects for its application in dentistry to reinforce the dental particulate composite. Objectives This study aimed to investigate the effect of oxygen or argon plasma treatment on polyethylene fibers. MATERIAL AND METHODS: Connect, Construct, InFibra, and InFibra treated with oxygen or argon plasma were topographically evaluated by scanning electron microscopy (SEM), and chemically by X-ray photoelectron spectroscopy (XPS). For bending analysis, one indirect composite (Signum) was reinforced with polyethylene fiber (Connect, Construct, or InFibra). The InFibra fiber was subjected to three different treatments: (1) single application of silane, (2) oxygen or argon plasma for 1 or 3 min, (3) oxygen or argon plasma and subsequent application of silane. The samples (25x2x2 mm), 6 unreinforced and 60 reinforced with fibers, were subjected to three-point loading tests to obtain their flexural strength and deflection. The results were statistically analyzed with ANOVA and the Bonferroni correction for multiple comparison tests. RESULTS: SEM analysis showed that oxygen and argon plasma treatments promote roughness on the polyethylene fiber surface. X-ray photoelectron spectroscopy (XPS) analysis shows that both plasmas were effective in incorporating oxygenated functional groups. Argon or oxygen plasma treatment affected the flexural strength and deflection of a fiber reinforced composite. The application of silane does not promote an increase in the flexural strength of the reinforced composites. CONCLUSIONS: Oxygen and argon plasma treatments were effective in incorporating oxygenated functional groups and surface roughness. The highest strength values were obtained in the group reinforced with polyethylene fibers treated with oxygen plasma for 3 min.

Comparison between the effect of plasma and chemical treatments on fiber post surface.

INTRODUCTION: The aim of the present study was to evaluate the fiber post surface after plasma and usual treatments and the adhesion between treated fiber posts and Rely X Unicem resin cement (3M ESPE, St Paul, MN). METHODS: Flat fiber posts were divided into 6 groups according to surface treatment: silane, hydrofluoric acid, hydrofluoric acid plus silane, plasma polymerization with argon, ethylenediamine plasma (EDA), and the control group. A goniometer was used to measure the contact angle between the groups with water or resin cement. Scanning electron microscopy and electron dispersive spectroscopy were used to examine the topography and chemical changes in the post surfaces after treatment. Push-out tests were performed using a universal testing machine to evaluate the adhesion strength between treated fiber posts and resin cement. RESULTS: In the contact angle with water, the most hydrophilic surface was observed in samples treated with argon plasma, followed by treatments with silane and hydrofluoric acid plus silane. The hydrophobic characteristic was observed with EDA and hydrofluoric acid. The contact angle with dual resin cement showed lower values with argon and EDA, followed by silane and hydrofluoric acid plus silane. Electron dispersive spectroscopy analyses showed chemical modifications in the surface after different treatments although topographic changes were verified only with EDA plasma compared with the control. Push-out results did not show differences between groups compared with the control, except for EDA plasma treatment. CONCLUSIONS: Plasma treatment favored the wettability of the post surface by modifying it chemically. Adhesion improvement was only observed after EDA treatment.