Human pulp response to resin cements used to bond inlay restorations

Objective. The aim of this study was to evaluate the pulp response following cementation of inlays using two different resin cements.Methods. Deep Class V cavities were prepared on the buccal surface of 34 sound human premolars. impressions were taken and inlays were prepared which were cemented with the following luting materials-Group 1: Rely X(TM) Unicem. (3M ESPE); Group 2: Variolink(R) II (Ivoclar Vivadent). in Group 3 (control), after lining the cavity floor with Dycal(R) (Dentsply Caulk) the inlays were cemented with Rely X(TM) Unicem. Four additional teeth were used as an intact control group. For Variolink(R) II, the adhesive system Excite was used as part of the cementation procedure. After 7 or 60 days, the teeth were extracted and processed for histological assessment.Results. At 7 days, Rely X(TM) Unicern and Variolink(R) II system triggered in two samples a mild and moderate inflammatory response, respectively. At 60 days, the pulpal response decreased for both groups. A discrete persistent inflammatory response occurred in Group 2 in which displacement of resin components across the dentin tubules was observed. In the control group, normal histological characteristics were observed. The inflammatory response and tissue disorganization were related to the remaining dentin thickness between the cavity floor and the pulp tissue.Significance. Techniques for inlay cementation using distinct luting cements may cause specific pulpal damage. Variolink(R) II associated with the adhesive system Excite cause more aggressive effects to the pulp-dentin complex than Rely X(TM) Unicern cement when both are used to cement inlay restorations. (C) 2005 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

A marker-and-cell approach to free surface 2-D multiphase flows

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The effect of elevated blood cortisol levels on the extinction of a conditioned stress response in rainbow trout

Following previously published observations that a conditioned response (CR) was lost more quickly by rainbow trout (Oncorhynchus mykiss) exhibiting a high responsiveness to stressors than by low responding individuals this study was designed to investigate the effects of exogenous cortisol on the retention of a CR in unselected rainbow trout. Fish held in isolation were conditioned over a 10-day period by pairing an innocuous signal (conditioned stimulus, CS: a water jet played on the surface of the tank water) with a mild stressor (unconditioned stimulus, US: 30 min of confinement). This resulted in a brief elevation of plasma cortisol levels (the CR) when the fish was exposed to the CS only. The effect of exogenous cortisol on the retention of the CR was evaluated by comparing the performance of fish that received cortisol-containing slow-release intraperitoneal implants, with fish receiving vehicle-only implants. Retention of the CR was assessed at intervals up to 35 days after conditioning ceased. The CR was considered to be evident when 30 min following presentation of the CS, mean plasma cortisol levels were significantly higher in conditioned than untrained fish. on day 1 both cortisol-implanted and vehicle-implanted conditioned fish exhibited a CR. However, from day 5 onwards the CR was observed only in the vehicle-implanted and conditioned group. This finding indicates that administration of cortisol accelerated the extinction of the CR in the cortisol-implanted fish, suggesting that elevated plasma cortisol levels can impair memory processes in rainbow trout. (c) 2006 Elsevier B.V. All rights reserved.

Quantification of bovine cytokine gene expression using real-time RT-PCR methodology

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

Remarks on Parametric Surface Waves in a Nonlinear and Non-Ideally Excited Tank

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Response of human alveolar bone-derived cells to a novel poly(vinylidene fluoride-trifluoroethylene)/barium titanate membrane

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

Image analysis for assessing broiler breeder behavior response to thermal environment

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

The use of ultrasound for cleaning the surface of stainless steel and nickel-titanium endodontic instruments

Aim the aim of this study was to evaluate the efficacy of ultrasound in cleaning the surface of stainless steel and Ni-Ti endodontic instruments.Methodology Twenty nickel-titanium instruments (10 Quantec files and 10 Nitiflex) and 20 stainless steel K-files (10 Maillefer-Dentsply and 10 Moyco Union Broach) were removed from their original packages and evaluated using a scanning electron microscope. Scores were given for the presence of residues on the surface or the instruments. The instruments were then cleaned in an ultrasonic bath containing only distilled water or detergent solution for 15 min, and re-evaluated, using scanning electron microscopy.Results Before cleaning, a greater amount of metallic debris was observed on the nickel-titanium Quantec instruments (P < 0.05), when compared to those made of stainless steel. Statistical analysis showed that the use of ultrasound was effective for cleaning the instruments, regardless of the irrigating solution or the instruments type (P < 0.05).Conclusions the use of ultrasound proved to be an efficient method for the removal of metallic particles from the surface of stainless steel and Ni-Ti endodontic instruments.

Surface pressure-area isotherms for Langmuir monolayers and a docking molecular orientation of perylene tetracarboxylic derivatives on a water surface

The surface pressure-molecular area (pi-A) isotherms for Langmuir monolayers of four perylenetetracarboxylic (PTCD) derivatives, measured with varying subphase temperatures and compression speeds, are reported. The behavior of these PTCD derivatives at the water-air interface is modeled using the rigid docking method. This approach is the first attempt to model the molecular orientation of PTCD on the water surface to be compared with experimental Langmuir isotherms. Through this methodology, it would be possible to anticipate aggregation and determine if favorable spatial orientations of perylenes are generated on the water surface. The pi-A isotherm experiments show that these molecules can support high surface pressures, indicating strong packing on the water surface and that the isotherms are compression speed independent but temperature dependent. The molecular orientation and stacking was further examined in Langmuir-Blodgett (LB) monolayers deposited onto glass and glass coated with Ag island films using UV-visible absorption and surface-enhanced fluorescence (SEF) measurements.

Inflammatory response to different endodontic irrigating solutions

Aim the aim of this study was to evaluate the inflammatory response to irrigating solutions injected into the peritoneal cavity of mice.Methodology Sixty mice received intra-peritoneal injections of 0.3 mL of 0.5% sodium hypochlorite, 2.0% chlorhexidine digluconate or phosphate buffered saline (PBS, control). Five animals of each group were sacrificed at 4, 24, 48 h and 7 days after the injection. Liquid from the peritoneal cavity of each animal was collected for the total and differential counting of inflammatory cells and protein leakage.Results the 0.5% sodium hypochlorite solution group had greater migration of neutrophils and mononuclear cells to the peritoneal cavity from 48 to 168 h (P < 0.05). There was a significant increase in protein leakage to the peritoneal cavity after 4 up to 48 h in the 0.5% sodium hypochlorite group compared to the control group. Protein leakage was similar in all groups at 168 h. The 2.0% chlorhexidine group had similar results to the control group at all time periods.Conclusions the 0.5% sodium hypochlorite solution induced an inflammatory response, however, the 2.0% chlorhexidine digluconate solution did not induce a significant inflammatory response.

Fluoride dose response in pH-cycling models using bovine enamel

The aim of this study was to establish methodologies for verification of the fluoride solution dose-response relationship using bovine enamel and pH-cycling models. Six models of the cariogenic challenge were performed, varying the time of demineralization and pH, time of remineralization, composition of de- and remineralization solutions, frequency and time of application of treatment solutions and pH-cycling duration. For the evaluation of the fluoride effect on caries dynamics, two proposed models provided for improvement in standardization of methods leading to a higher level of precision, demonstrating a dose response between treatments with regard to surface microhardness and Delta Z. For the evaluation of the fluoride effect on enamel remineralization, the addition of fluoride to the de- and remineralization solutions and the reduction of frequency and time of application of fluoride solutions led to a more suitable pH-cycling model. Copyright (C) 2005 S. Karger AG, Basel.

Reagentless biosensor for isocitrate using one step modified Pt-Ir microelectrode

The Pt-Ir microelectrode modified through one step, electropolymerization is proposed for the isocitrate amperometric biosensor construction. The enzyme (isocitrate dehydrogenase-ICDH), coenzyme (NADP(+)) and mediator (Meldola's Blue) were immobilized onto the microelectrode surface in one step from a PIPES buffer solution containing pyrrole. The optimized experimental conditions were 25 cycles of cyclic voltammetric in a solution containing 3.58 10(-5) mol l(-1) of mediator, 3.51 10(-4) mol l(-1) of coenzyme and 2.68 U ml(-1) of enzyme. In contrast to the biosensor for isocitrate reported in literature, just one enzyme was immobilized and no coenzyme addition in the solution of analysis was necessary. Catalytic currents were proportional to the isocitrate concentration between 7.7 10(-6) and 1.04 10(-4) mol l(-1), showing good repeatability. The detection limit of the proposed biosensor was 3.50 10(-6) mol l(-1), the response time was lower than 20 s, the lifetime was about 30 determinations and no significant interference of sugars and citric acid was verified. Orange juice samples were analysed by both methodology biosensor and spectrophotometric commercial kit, and the obtained results presented a good correlation. The data demonstrated that the developed biosensor is suitable for isocitrate determination in orange juice without matrix interferences. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Influence of Sources and Meteorology on Surface Concentrations of Gases and Aerosols in a Coastal Industrial Complex

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The influence of hydrogen plasma pre-treatment on the structure of BDND electrode surface applied for phenol detection

The surface properties of boron-doped nanocrystalline diamond films treated with H(2) plasma was investigated in regard to their electrochemical response for phenol oxidation. The surface of these films is relatively flat formed by crystallites with sizes of about 40 nm. X-ray photoelectron spectroscopy analyses showed that electrode surface has a high amount of C-H bonds. This behavior is in agreement with Mott-Schottky plot measurements concerning the flat band potential that presented a value as expected for hydrogenated diamond surface. This electrode presented the phenol detection limit of 0.08 mg L(-1) for low phenol concentrations from 40 to 250 mu mol L(-1).

Optimization of Radial Basis Function neural network employed for prediction of surface roughness in hard turning process using Taguchi's orthogonal arrays

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)