Penetration of resin‐based materials into initial erosion lesion: A confocal microscopic study

The application of resin‐based materials is an alternative of treatment for eroded lesions. Nevertheless, there are no studies about the penetration of these materials into eroded lesion, which might affect its adhesion. Therefore, this study evaluated the penetration of four resin‐based materials, with and without enamel etching. By using an in vitro protocol, types of treatment were studied at five levels (AdheSE^®, Tetric N‐Bond^®, Single Bond 2^®, Helioseal Clear^®, Icon^®) and types of enamel etching in two levels (with and without). Materials were stained with 0.02 mg/mL ethanolic solution of tetramethylrhodamine isothiocyanate. Bovine enamel samples (4 × 4 mm) were immersed in 0.01 M HCl, pH 2.3, for 30 seconds to produce initial eroded lesions. Afterward, the materials were applied on half of sample enamel surface following the manufacturer's instructions. On the other half of sample, the materials were applied without etching the enamel. Materials penetration into the enamel was assessed by Confocal Laser Scanning Microscopy on reflection and fluorescence modes. The penetration depth (PD) was measured using ImageJ software. Data were analyzed by two‐way ANOVA and Tukey test (P < 0.05). Regardless of the material, etched enamel resulted in higher PD than non‐etched (P < 0.05). Icon^® showed the highest PD in enamel followed by Helioseal Clear^® (P < 0.05), with significant difference between them (P < 0.05) and no difference was found among AdheSE^®, Tetric N‐Bond^®, and Single Bond 2^® (P > 0.05). It can be concluded that prior enamel etching increased the materials penetration into eroded enamel and the Icon^®—infiltrant presented highest penetration. Microsc. Res. Tech. 79:72–80, 2016. © 2015 Wiley Periodicals, Inc.     

Analysis of the energy intensity evolution in the Brazilian industrial sector—1995 to 2005

This study developed a method to evaluate the evolution of energy intensity in the Brazilian industrial sector from 1995 to 2004. In order to do so, it was necessary to obtain six different measures (indicators) of the sector energy intensity. Considering the concept of energy intensity as the ratio between energy consumption and the level of economic activity, two measures were used for the energy consumption: a thermal (physical) and an economic one. For the level of economic activity, three measures were used: value of production, value of delivered goods and added value. In the Brazilian industrial sector, most of these indicators have behaved in a similar way. In a disaggregated way, energy intensity indicators show a unified direction of its evolution. However, a more elaborate study on the consumption profile of the Brazilian industrial sector and its economical activities indicates the presence of important deviations concerning the annual rate of change in energy intensity. Besides, there is no evident relation between these deviations and the composition of the different indicators of energy intensity.