The aim of this work was to investigate the mechanical properties of the titanium anodic films (TiO2) produced by anodic oxidation under galvanostatic conditions, using a 1.4M phosphoric acid electrolyte, with different current densities (J) on commercially pure titanium (cp-Ti). The morphology of the oxide films were observed by scanning electron microscopy (SEM), whereas the composition of the film was determined by Raman spectroscopy. Porosity, average roughness (Ra) and thickness of the TiO2 films increased with the applied J. Hardness and elastic modulus were measured by instrumented indentation technique, and the influence of the substrate was corrected using analytical models. The anodic films presented higher hardness and lower elastic modulus values compared with the cp-Ti.

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This paper presents an experimental investigation on the applicability of the Barcelona (BCN) test to evaluate the mechanical properties of a Macro-Synthetic Fiber Reinforced Concrete (MSFRC) submitted to high temperature environments (up to 600°C). BCN tests demonstrated that the MSFRC gradually loses tensile strength an energy consumption density with increasing temperature. Temperatures of 400°C and 570°C shown to be critical to the MSFRC mechanical performance. The residual mechanical behavior of the macro-synthetic fibers was not affected by the temperature up to 100°C. For higher temperatures, the reinforcement showed that may lose part of its crystallinity compromising the MSFRC post-cracking performance. The constitutive model used to determine the stress-strain curves of the MSFRC was capable to reproduce the composite behavior after the event of a fire.

Objective:The aim of the present study was to evaluate the efficacy of resin infiltration in preventing in vitro lesion progression.Materials and Methods:Buccal surfaces of bovine incisors were divided into mesial and distal regions and, at the center, nail varnish was applied (1.0 mm width) to protect the enamel surface against any further treatment. In order to create artificial enamel lesions in the unprotected areas, each specimen was soaked in a demineralizing solution. After that, specimens had two enamel lesions. One lesion in each sample was etched with 15% HCl for 120 s and infiltrated with a commercial infiltrating resin for 3 min, while the other lesion was not treated (control). Each specimen was cross-sectionally halved and randomly allocated to two groups: Group 1 was immediately processed and Group 2 was submitted to a new demineralization process. The samples were analyzed by means of cross-sectional hardness measurements using a nanoindenter equipment. Hardness data were statistically analyzed by non-parametric Kruskal-Wallis and MannWhitney tests (α = 0.05).Results:The findings showed statistical difference between treatments at the same analyzed distance range from the outer surface of the enamel (P < 0.05).Conclusion:The untreated lesion showed lower hardness values for distances near the outer surface of the enamel. The resin infiltration was efficient in preventing further in vitro demineralization of bovine enamel lesions.

Summary Oxaliplatin (OP) is an anti‐tumor agent used for advanced colorectal cancer treatment. Therapies with OP produce side effects, which could be reduced by its encapsulation into PLGA microspheres (MS). The determination of OP content in MS is important for defining the exact quantity of loaded particles into final formulation and achieve correct dosage of this drug. This research focuses on determining OP through the Pt residue which is quantified by thermogravimetric analysis (TGA). It was demonstrated that there is no significant difference between the intrinsic residues for MS obtained with the PLA or PLGA. In turn, a statistically significant difference was detected between residue of tested polymers. The linearity was proved (R2 = 0.9998) by evaluating samples prepared from mixtures of empty PLGA MS and known quantities of OP. The detection limit was equal to 0.25% Pt residue while the quantitation limit was equal to 0.78%. Thus, TGA allows to quantify oxaliplatin loadings as small as 1.57 wt% in samples of 20 mg.

Objective: To evaluate the material composition, mechanical properties (hardness and elastic modulus), and scratch resistance of the coating of four commercialized esthetic orthodontic archwires. Materials and Methods: The coating composition of esthetic archwires was assessed by Fouriertransform infrared spectroscopy (FTIR). Coating hardness and elastic modulus were analyzed with instrumented nano-indentation tests. Scratch resistance of coatings was evaluated by scratch test. Coating micromorphologic characteristics after scratch tests were observed in a scanning electron microscope. Statistical differences were investigated using analysis of variance and Tukey post hoc test. Results: The FTIR results indicate that all analyzed coatings were markedly characterized by the benzene peak at about 1500 cm 21. The coating hardness and elastic modulus average values ranged from 0.17 to 0.23 GPa and from 5.0 to 7.6 GPa, respectively. Scratch test showed a high coating elasticity after load removal with elastic recoveries .60%, but different failure features could be observed along the scratches. Conclusion: The coatings of esthetic archwires evaluated are probably a composite of polyester and polytetrafluoroethylene. Delamination, crack propagation, and debris generation could be observed along the coating scratches and could influence its durability in the oral environment. (Angle Orthod. 2015;85:777-783.)