Effect of bleaching agents and soft drink on titanium surface topography

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of Abutment Screw Surface Treatment on Reliability of Implant-Supported Crowns

Purpose: To evaluate and compare the reliability of implant-supported single crowns cemented onto abutments retained with coated (C) or noncoated (NC) screws and onto platform-switched abutments with coated screws. Materials and Methods: Fifty-four implants (DT Implant 4-mm Standard Platform, Intra-Lock International) were divided into three groups (n = 18 each) as follows: matching-platform abutments secured with noncoated abutment screws (MNC); matching-platform abutments tightened with coated abutment screws (MC); and switched-platform abutments secured with coated abutment screws (SC). Screws were characterized by scanning electron microscopy and x-ray photoelectron spectroscopy (XPS). The specimens were subjected to step-stress accelerated life testing. Use-level probability Weibull curves and reliability for 100,000 cycles at 200 N and 300 N (90% two-sided confidence intervals) were calculated. Polarized light and scanning electron microscopes were used for fractographic analysis. Results: Scanning electron microscopy revealed differences in surface texture; noncoated screws presented the typical machining grooves texture, whereas coated screws presented a plastically deformed surface layer. XPS revealed the same base components for both screws, with the exception of higher degrees of silicon in the SiO2 form for the coated samples. For 100,000 cycles at 300 N, reliability values were 0.06 (0.01 to 0.16), 0.25 (0.09 to 0.45), and 0.25 (0.08 to 0.45), for MNC, MC, and SC, respectively. The most common failure mechanism for MNC was fracture of the abutment screw, followed by bending, or its fracture, along with fracture of the abutment or implant. Coated abutment screws most commonly fractured along with the abutment, irrespective of abutment type. Conclusion: Reliability was higher for both groups with the coated screw than with the uncoated screw. Failure modes differed between coated and uncoated groups.

Silica-based Nano-coating on Zirconia Surfaces Using Reactive Magnetron Sputtering: Effect on Chemical Adhesion of Resin Cements

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo de rochas alcalinas intrusivas na região de Três Fontes - MG

Geological researches conducted in the past few years detected, through deep drill hole data, the presence of alkaline rocks in the region of Três Fontes-MG, where the Barbacena Group rocks, the Morro do Ferro Greenstone Belt rocks and Araxá/Canastra groups‟ rocks are exposed. This paper aimed the petrographic and chemical characterization of these alkaline rock types, which have not yet been described in the literature. Based on petrographic descriptions and geochemical and Scanning Electron Microscopy analysis, it was possible to characterize the rock in question as lamprophyre, rich in carbonates, phlogopite, pyroxene, olivine, titaniferous opaque minerals and apatite concentrations that reach 7%. This occurrence corresponds to an alkaline intrusion, which caused brecciation of host rocks, possibly indicating that the material is explosive, however, in the study area there was no evidence of volcanic activity on the surface

Estudo das características fluidodinâmicas do bagaço de cana de açúcar para aplicações da gaseificação no setor sucroalcooleiro

In this work is studied the fluid dynamic characteristics of sugarcane bagasse for gasification applications and use of syngas in the sugarcane sector. This is an experimental work, which is initially performed the particle size separation of sugarcane bagasse particles, using appropriate equipment. Through the experiment is possible to determine the average diameter of particles pomace typical sugarcane mill. The equipment used for the grading sieve separation assembly consists of several dimensions, arranged vertically and which shows adequate for good separation from the pulp. Later, it makes immediate analysis for the determination of moisture, ash, volatile materials and fixed carbon. The study also determines the gross calorific value and allows analysis of densities of particles of sugar cane bagasse. Also studied the bagasse morphology using electron microscopes, where it was possible to visualize the geometry of the particles of bagasse. The use of Electronic Scanning Microscopy (SEM) provided better understand the morphology and particle size measured by using photography methods. Two methods for determining the sphericity of the particles were also used. The experiments carried out using appropriate standards and specific equations, allowing compare the present results with the values found by several researchers. Subsequently, fluid dynamic simulations were performed for the determination of porosity and minimum fluidization velocity theoretical. It follows that the sphericity and porosity of the bagasse particles influence the minimum fluidization velocity of biomass

Supported core-shell nanobiosensors for quantitative fluorescence imaging of extracellular pH

Covalent “click” cycloaddition was used to functionalize silica substrates with pH-sensitive nanoparticles, thus producing uniform and highly luminescent analytical devices usable in both commercial fluorimeters and fluorescence microscopes. Quantitative and spatially-resolved extracellular pH measurements were successfully achieved on live cardiac fibroblasts with these novel ion-sensitive surfaces.

Processamento de fotomicrografias por meio da transformada wavelet starlet

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dielectric behaviour of CaCu3Ti4O12-epoxy composites

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Correlative light-electron fractography of interlaminar fracture in a carbon-epoxy composite

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Elaboração de um material didático aplicado ao ensino de física para utilização do experimento virtual da dupla fenda

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo da distribuição das proteínas relacionadas às teneurinas no sistema nervoso central de primatas não-humanos (Sapajus spp) e ratos (Rattus norvegicus)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo da distribuição das proteínas relacionadas às teneurinas no sistema nervoso central de primatas não-humanos (Sapajus spp) e ratos (Rattus norvegicus)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The Endothelial Sample Size Analysis in Corneal Specular Microscopy Clinical Examinations

Purpose: To evaluate endothelial cell sample size and statistical error in corneal specular microscopy (CSM) examinations. Methods: One hundred twenty examinations were conducted with 4 types of corneal specular microscopes: 30 with each BioOptics, CSO, Konan, and Topcon corneal specular microscopes. All endothelial image data were analyzed by respective instrument software and also by the Cells Analyzer software with a method developed in our lab(US Patent). A reliability degree (RD) of 95% and a relative error (RE) of 0.05 were used as cut-off values to analyze images of the counted endothelial cells called samples. The sample size mean was the number of cells evaluated on the images obtained with each device. Only examinations with RE<0.05 were considered statistically correct and suitable for comparisons with future examinations. The Cells Analyzer software was used to calculate the RE and customized sample size for all examinations. Results: Bio-Optics: sample size, 97 +/- 22 cells; RE, 6.52 +/- 0.86; only 10% of the examinations had sufficient endothelial cell quantity (RE<0.05); customized sample size, 162 +/- 34 cells. CSO: sample size, 110 +/- 20 cells; RE, 5.98 +/- 0.98; only 16.6% of the examinations had sufficient endothelial cell quantity (RE<0.05); customized sample size, 157 +/- 45 cells. Konan: sample size, 80 +/- 27 cells; RE, 10.6 +/- 3.67; none of the examinations had sufficient endothelial cell quantity (RE>0.05); customized sample size, 336 +/- 131 cells. Topcon: sample size, 87 +/- 17 cells; RE, 10.1 +/- 2.52; none of the examinations had sufficient endothelial cell quantity (RE>0.05); customized sample size, 382 +/- 159 cells. Conclusions: A very high number of CSM examinations had sample errors based on Cells Analyzer software. The endothelial sample size (examinations) needs to include more cells to be reliable and reproducible. The Cells Analyzer tutorial routine will be useful for CSM examination reliability and reproducibility.

A novel spermatozoan ultrastructure in the shrimp Hippolyte obliquimanus Dana, 1852 (Decapoda: Caridea: Hippolytidae)

The aim of this study was to describe and illustrate the morphology of the spermatozoon of the Western Atlantic shrimp, Hippolyte obliquimanus. Individuals were sampled from Itagua Beach (Ubatuba, southern Brazil). The male reproductive system was dissected and morphological analysis was undertaken using a stereomicroscope, a light microscope, and transmission electron and scanning electron microscopes. When viewed from the nuclear or acrosomal poles, each spermatozoon has many translucent radiating arms (about 20) from a denser cell body, while laterally the cell body and arms resemble a "cnidarian medusa", with all the arms projecting away from the bell-like cell body. This sperm morphology is distinct from the "thumbtack"-shaped spermatozoa observed in the majority of carideans but has similarities to the spermatozoa of Rhynchocinetes spp. The morphology of sperm of several species of the genus Hippolyte resembles the spermatozoon of H. obliquimanus with the presence of posterior nuclear arms, but it is necessary to study other Hippolyte species to place these arms in the context of the genus.

Fatigue Reliability of 3 Single-Unit Implant-Abutment Designs

Objectives: Because the mechanical behavior of the implant-abutment system is critical for the longevity of implant-supported reconstructions, this study evaluated the fatigue reliability of different implant-abutment systems used as single-unit crowns and their failure modes. Methods and Materials: Sixty-three Ti-6Al-4V implants were divided in 3 groups: Replace Select (RS); IC-IMP Osseotite; and Unitite were restored with their respective abutments. Anatomically correct central incisor metal crowns were cemented and subjected to separate single load to failure tests and step-stress accelerated life testing (n = 18). A master Weibull curve and reliability for a mission of 50,000 cycles at 200 N were calculated. Polarized-light and scanning electron microscopes were used for failure analyses. Results: The load at failure mean values during step-stress accelerated life testing were 348.14 N for RS, 324.07 N for Osseotite, and 321.29 N for the Unitite systems. No differences in reliability levels were detected between systems, and only the RS system mechanical failures were shown to be accelerated by damage accumulation. Failure modes differed between systems. Conclusions: The 3 evaluated systems did not present significantly different reliability; however, failure modes were different. (Implant Dent 2012;21:67-71)