The surface and phase analysis studies on dental bioceramics subjected to different mouthrinse solutions

In this study, three bioceramic materials, [IPS Empress® CAD (Ivoclar), IPS e.max® CAD (Ivoclar), and Lava Ultimate® CAD (3 M ESPE)] were treated with three commercial mouthrinses [Listerine, Tantum Verde and Klorhex]; and surface phase changes were then assessed. The samples were prepared with dimensions of 2 × 12 × 14 mm. They were immersed in the mouthrinse solutions by using a home-made agitation instrument for 120 h, but for the control group, the rinsing solution was distilled water. Surface phase changes were measured by X-ray diffraction (XRD) device (Bruker AXS D8 Advance, USA), and the change of surface roughness was inspected by scanning electron microscopy (LEO 440 Computer Controlled Digital, UK). XRD patterns of IPS e.max® CAD, IPS empress® CAD, and Lava Ultimate® CAD were evaluated in the study and phases were determined as different mouthwash deterioration then the effects of peak formation was indicated. Phases were seen some differentiation in terms of the crystalline structure. SEM images to investigate the surface roughness of the samples were employed. When the distilled water was applied, the surface was smoother and compact, but the surface of the samples subjected to Tantum Verde, Klorhex, and Listerine showed that the surface was deformed by erosive wear and corrosion of the ingredients. This work implied that mouthrinse with lower alcohol content had less deteriorating effect on the bioceramic materials. In terms of phase and surface roughness change, Lava Ultimate® CAD has been effected the most corroded surface among used bioceramics owing to organic content concentration. © 2018, Australian Ceramic Society

Preparation of compatible blends of poly(methyl methacrylate) used in dentistry with a reactive terpolymer containing maleic anhydride and their thermomechanical characterization

This study focuses on the preparation of compatible blends with the poly(methyl methacrylate) (PMMA) using a reactive terpolymer maleic anhydride-styrene-vinyl acetate (MA-St-VA). In the first series of experiments, binary blends of the PMMA and the MA-St-VA terpolymer have been prepared in tetrahydrofurane. The PMMA and the MA-St-VA terpolymer formed the compatible blends. The effects on thermomechanical properties of MA-St-VA terpolymer ratio in the blends were studied. The glass transition temperatures (T-g), thermal expansion coefficient (alpha), and other thermomechanical parameters for the blends have been established by TMA method and the compatibility of two polymers has been evaluated by these TMA parameters. The addition of MA-St-VA terpolymer to PMMA made a plasticizing effect on PMMA. This effect regularly changed with the increasing of the terpolymer in the blends. (c) 2006 Wiley Periodicals, Inc

Evaluation of Laser Treatment on Reline-Base Composites

The effects of different laser treatments on some mechanical properties of acrylic resin and soft liner were investigated. A total of 60 test specimens were fabricated according to test requirements. The specimens were roughened with Potassium-ticanyl-Phosphate (KTP), Er:YAG, and Nd:YAG lasers before application of soft liner. The flexural, peel, and tensile bond strengths were measured using a universal testing machine. Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) spectra of surfaces were also obtained to evaluate changes on the lased surfaces. No significant difference was apparent between the tensile bond strength values of the groups. Although peel strength values obtained for each of the laser types were lower than those of the control group, flexural strength values were higher than those of the control specimens. The spectra of specimens showed that lasing led to some chemical changes on the resin surfaces. Physical changes on the treated surfaces were visualized by scanning electron microscopy (SEM) analysis. Results of this study suggest that such treatments may be warranted because of the increase in flexural strength