Estudo da influência do plasma de Ar e H2 nas propriedades de materiais cerâmicos para aplicação odontológica.

Abstract

Currently the development of research on ceramic materials aims to produce resistant, tenacious ceramics, with physical-chemical adhesion at the interfaces of infrastructure and aesthetic covering, as well as, at the cement interface, aiming to get an adequate aesthetic appearance and a trustworthy performance for odontological applications. This work had as objective to evaluate the influence of the plasma of Argon and Hydrogen, on the properties of the alumina based ceramics infiltrated with lanthanum aluminosilicate glass obtained by conventional sintering and plasma treatment for odontological application. Initially, the starting substances were chemically characterized and test bodies were manufactured in accordance to with the method recommended for the utilized ceramic system according to the Norm ISO 6872, for ceramic infrastructure.The substrates were submitted to FT-IR spectroscopy, Optical Microscopy, Scanning Electron Microscopy, Energy-dispersive X-ray Spectroscopy (EDS), the contact angle adhesion and sessile drop adhesion, Xray diffraction (DRX), X-ray Fluorescence, Resistance to three point deformation, Microhardness Vickers, Mercury Porosimetry and cell toxicity. The FT-IR results presented structural information via characteristic bands of functional groups of molecules considered in study. By Electron microscopy, a composite microstructure of alumina, glass and lanthanum aluminosilicate was observed, which was confirmed through EDS analysis. From X-ray diffraction, the chemical compounds were confirmed, without significant variation of the cristallinity, crystal size and microdeformations. The adhesion allowed to classify the surfaces in hydrophilic or hydrophobe ones. The samples with plasma and glass (284,14 MPa ± 10,86), presented the highest values for the deformation resistance test at three points, followed by the conventional sample (257,82 MPa ± 12,42), plasma (221,06 MPa ± 15,25) and the sintered ones without glass (32,98 MPa ± 6,66). The biggest average values of microhardness Vickers were found for the samples with plasma and glass (1505,40 ± 199,42). The applied statistical method was the F test (ANOVA) with comparisons of Tukey and the t-Student test, with significant differences in the confidence levels of 5% and p< 0,001, respectively. The ceramic test bodies presented physicalchemical modifications of the surface, with increase of 10,20% in the deformation resistance and 28,53% in microhardness Vickers, when compared to those with conventional treatment.