Effect of ageing and immersion in different beverages on properties of denture lining materials

OBJECTIVES: To evaluate the color stability and hardness of two denture liners obtained by direct and indirect techniques, after thermal cycling and immersion in beverages that can cause staining of teeth. MATERIAL AND METHODS: Seventy disc-shaped specimens (18 x 3 mm) processed by direct (DT) and indirect techniques (IT) were made from Elite soft (n=35) and Kooliner (n=35) denture liners. For each material and technique, 10 specimens were subjected to thermal cycling (3,000 cycles) and 25 specimens were stored in water, coffee, tea, soda and red wine for 36 days. The values of color change, Shore A hardness (Elite soft) and Knoop hardness (Kooliner) were obtained. The data were subjected to ANOVA, Tukey's multiple-comparison test, and Kruskal-Wallis test (P<0.05). RESULTS: The thermal cycling promoted a decrease on hardness of Kooliner regardless of the technique used (Initial: 9.09± 1.61; Thermal cycling: 7.77± 1.47) and promoted an increase in the hardness in the DT for Elite Soft (Initial: 40.63± 1.07; Thermal cycling: 43.53± 1.03); hardness of Kooliner (DT: 8.76± 0.95; IT: 7.70± 1.62) and Elite Soft (DT: 42.75± 1.54; IT=39.30± 2.31) from the DT suffered an increase after the immersion in the beverages. The thermal cycling promoted color change only for Kooliner in the IT. Immersion in the beverages did not promote color change for Elite in both techniques. The control group of the DT of Kooliner showed a significant color change. Wine and coffee produced the greatest color change in the DT only for Elite Soft when compared to the other beverages. CONCLUSION: The three variation factors promoted alteration on hardness and color of the tested denture lining materials.

Influence of surface sealant on the translucency of composite resin: effect of immersion time and immersion media

This study evaluated the effect of surface sealant on the translucency of composite resin immersed in different solutions. The study involved the following materials: Charisma, Fortify and coffee, Coca-Cola®, tea and artificial saliva as solutions. Sixty-four specimens (n = 8) were manufactured and immersed in artificial saliva at 37 ± 1 °C. Samples were immersed in the solutions for three times a day and re-immersed in artificial saliva until the translucency readings. The measurements were carried out at nine times: T1 - 24 hours after specimen preparation, T2 - 24 hours after immersion in the solutions, T3 - 48 hours and T4 to T9 - 7, 14, 21, 30, 60 and 90 days, respectively, after immersion. The translucency values were measured using a JOUAN device. The results were subjected to ANOVA and Tukey's test at 5%. The surface sealant was not able to protect the composite resin against staining, the coffee showed the strongest staining action, followed by tea and regarding immersion time, a significant alteration was noted in the translucency of composite resin after 21 days.

Composite resin color stability: influence of light sources and immersion media

OBJECTIVE: This study evaluated the influence of light sources and immersion media on the color stability of a nanofilled composite resin. MATERIAL AND METHODS: Conventional halogen, high-power-density halogen and high-power-density light-emitting diode (LED) units were used. There were 4 immersion media: coffee, tea, Coke® and artificial saliva. A total of 180 specimens (10 mm x 2 mm) were prepared, immersed in artificial saliva for 24 h at 37±1ºC, and had their initial color measured with a spectrophotometer according to the CIELab system. Then, the specimens were immersed in the 4 media during 60 days. Data from the color change and luminosity were collected and subjected to statistical analysis by the Kruskall-Wallis test (p<0.05). For immersion time, the data were subjected to two-way ANOVA test and Fisher's test (p<0.05). RESULTS: High-power-density LED (ΔE=1.91) promoted similar color stability of the composite resin to that of the tested halogen curing units (Jet Lite 4000 plus - ΔE=2.05; XL 3000 - ΔE=2.28). Coffee (ΔE=8.40; ΔL=-5.21) showed the highest influence on color stability of the studied composite resin. CONCLUSION: There was no significant difference in color stability regardless of the light sources, and coffee was the immersion medium that promoted the highest color changes on the tested composite resin.

A high voltage pulse power supply for metal plasma immersion ion implantation and deposition

We describe the design and implementation of a high voltage pulse power supply (pulser) that supports the operation of a repetitively pulsed filtered vacuum arc plasma deposition facility in plasma immersion ion implantation and deposition (Mepiiid) mode. Negative pulses (micropulses) of up to 20 kV in magnitude and 20 A peak current are provided in gated pulse packets (macropulses) over a broad range of possible pulse width and duty cycle. Application of the system consisting of filtered vacuum arc and high voltage pulser is demonstrated by forming diamond-like carbon (DLC) thin films with and without substrate bias provided by the pulser. Significantly enhanced film/substrate adhesion is observed when the pulser is used to induce interface mixing between the DLC film and the underlying Si substrate. (C) 2010 American Institute of Physics. [doi:10.1063/1.3518969]

Modification of surface properties of Ti-16Si-4B powder alloy by plasma immersion ion implantation

Results of the surface modification of Ti-16Si-4B powder alloy by nitrogen ion implantation are presented, together with the experimental description of the preparation of that powder by high-energy ball milling and hot pressing. The phase structure, chemical composition and morphology of sample surfaces were observed by utilizing X-ray diffractometer (XRD), atomic force microscope (AFM) and scanning electron microscopy (SEM). A tribological characterization was carried out with a ball-on-disc tribometer and an SEM. Friction coefficient is compared with the one obtained for Ti-6Al-4V alloy and the wear scars characterized by SEM/EDS (energy dispersive spectroscopy). The concentration profile of the detected elements have been investigated using Auger electron spectroscopy (AES) depth profiling. Our results show that a shallow implanted layer of oxygen and nitrogen ions were obtained at the Ti-16Si -4B alloy surface, sufficient to modify slightly its tribological properties. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.

A randomised controlled trial evaluating the effect of immersion bath on labour pain

Objective: to evaluate the effect of an immersion bath on pain magnitude during the first stage of tabour. Design: a randomised controlled trial comparing the pain scores of bathing and non-bathing nulliparous women during birth was employed. Setting: the study was conducted at the Normal Birth Center of Amparo Maternal, Sao Paulo, Brazil. Participants: 108 birthing women, with 54 women randomly assigned to each group. Interventions: when the birthing women presented at 6-7cm of cervical dilation, they were placed in an immersion bath for 60 mins. Outcome measures: pain scores, using a behavioural pain scale and a numeric scale, were recorded at two evaluation time points: at 6-7cm of cervical dilation and 1 h after the first pain score evaluation. Findings: at the first evaluation, on the behavioural scale, the means were 2.1 for both groups (p = 0.914; 95% confidence intervals (CI) 1.9-2.3 for the control group and 2.0-2.2 for the experimental group). On the numeric scale, the means were 8.7 and 8.5 for the control and experimental groups, respectively (p = 0.235; 95% Cl 8.2-9.2 for the control group and 8.1-8.9 for the experimental group). At the second evaluation, the pain score means for both scales were statistically higher in the control group than in the experimental group. On the behavioural scale, the scores were 2.4 vs. 1.9, respectively, for the control and experimental groups (p<0.001; 95% Cl 2.2-2.6 for the control group and 1.7-2.1 for the experimental group). On the numeric scale, the scores were 9.3 vs. 8.5, respectively, for the control and experimental groups (p<0.05; 95% Cl 8.9-9.7 for the control group and 8.1-8.9 for the experimental group). Conclusions: mean tabour pain scores in the control group were significantly higher than those in the experimental group. The present findings suggest that use of an immersion bath is a suitable alternative form of pain relief for women during tabour. (C) 2007 Elsevier Ltd. All rights reserved.

Evaluation of sutures after immersion in nonalcoholic benzydamine hydrochloride mouthrinse by scanning electron microscopy

This study evaluated the surface integrity of sutures after immersion in mouthrinse or water, by scanning electron microscopy (SEM) analysis. Pieces of resorbable suture remaining after oral surgery were immediately collected. Twelve pieces each of catgut, chromed catgut, and polyglactin 910 were divided into four groups and immersed in pure mouthrinse, mouthrinse diluted in water at 1:1 and 1:2, or water (positive control), for 24 h. Three pieces each of new sutures were used as negative control. Specimens were placed on stubs and sputter coated with gold for SEM analysis. Observation of experimental groups and comparison with controls revealed that immersion in the mouthrinse at different dilutions did not alter their surface; slight, nonsignificant changes were found in some experimental specimens yet also in the positive control group. It was concluded that immersion of resorbable sutures in water or non-alcoholic benzydamine hydrochloride mouthrinse did not produce any significant change; therefore, this mouthrinse may be safely employed after oral surgery.

"Schwiiz brännt". Achtziger Jugendunruhen et scènes punks suisses : entre reprise, immersion et détachement

Au début des années 80, deux secousses touchent la Suisse avec d'un côté l'explosion du mouvement punk et de l'autre de fortes mobilisations au sein de la jeunesse du pays, les Achtziger Jugendunruhen. Cet article analyse l'articulation de ces deux phénomènes. Au sein d'un espace contestataire fortement composite, le punk finit par jouer un rôle central, le mouvement dans son ensemble mettant en avant certains enjeux culturels, reprenant des éléments de la panoplie punk comme l'édition de fanzine, et choisissant des musiciens punks parmi ses porte-paroles. Cette jonction marque la forte spécificité de la Suisse, autant par l'implication de la scène punk au sein d'un mouvement contestataire plus large que par la recrudescence des mobilisations de la jeunesse au moment où elles se font de plus en plus rares en Europe. Elle peut se comprendre par une communauté d'intérêts (obtenir des lieux pour exprimer sa propre culture) et de valeurs (l'opposition au conservatisme). Néanmoins, cette force présence des aspects culturels au sein des Achtziger Jugendunruhen ne doit pas conduire à les réduire à ces seuls enjeux. Au contraire, les différents discours du mouvement mettent en avant l'autonomie comme volonté de changement radical, ainsi que des revendications plus larges comme la solidarité internationale ou la question du logement. Ainsi cet article vise à la fois à mieux comprendre la nature des Achtziger Jugendunruhen et à développer une analyse historique des années 80 d'une part et du conservatisme helvétique d'autre part.

Wii-immersion: aprovechando las capacidades del Wiimote para la mejora de la sensación de inmersión

En este proyecto se proponen dos utilidades para mejorar la sensación de inmersión en un entorno virtual. Ambas utilidades pretenden aportar una interacción más intuitiva. Para ello, las dos se basan en capturar el movimiento del usuario a través de distintos dispositivos. En la primera utilidad se obtiene la posición de la cabeza del usuario y se visualiza la escena en base a dicha posición. Esto se consigue usando un Wiimote a modo de cámara infra-roja en combinación con unas gafas con leds infra-rojos para determinar la posición de la cabeza. La segunda utilidad consiste en un control gestual con seis grados de libertad. El control gestual permite manipular un objeto real, es decir, trasladarlo y rotarlo y que dicha manipulación se refleje en un objeto virtual. Manipulando el objeto es posible interactuar con el entorno virtual visualizado mediante el GTI Framework. La manipulación del control gestual permite interactuar de una forma muy natural, similar a como se interactuaría en un entorno real. Como objeto real se ha empleado un Wiimote en combinación con el periférico Motion Plus y una esfera luminosa ubicada en su extremo. El Motion Plus permite obtener la orientación, y mediante una cámara PlayStation Eye se detecta la esfera, que determina la posición del Wiimote

Immersion communautaire à Lausanne : une autre façon d'enseigner la santé publique [Community immersion in Lausanne: a different approach to teaching public health?].

Teaching community medicine represents a significant challenge for medical schools, which tend to struggle to promote interest in the issue among students. In 2009, the Lausanne medical school introduced a "community immersion" module specifically designed to address the issue. The new module requires students working in small groups under the supervision of a tutor to investigate a health question of their choice. The investigation involves conducting interviews with stakeholders (health professionals, patients, politicians, etc.), carrying out a survey, and presenting the results of the investigation in a "congress". An external evaluation showed that the objectives of the initiative had been largely achieved, with an increase of interest in community medicine for over 50% of students (based on a total cohort of 150 students) and a high level of satisfaction for over 90% of students and tutors. This paper presents the results of the initiative and its use for promoting community-oriented medicine.

Soluble sugars and germination of Annona emarginata (Schltdl.) H. Rainer seeds submitted to immersion in GA3 up to different water contents

The objective of this study was to evaluate the effect of different water contents achieved by Annona emarginata (Schltdl.) H. Rainer seeds during immersion in GA3 solutions, in variation of soluble sugars levels and germination. Seeds with 10% of initial water content were submitted to imbibition in GA3 solutions with concentrations of 0; 250; 500; 750 and 1000 mg L-1 and when they reached the water content of 15%, 20%, 25%, 30% and 35%, the quantification of soluble sugars levels and germination test were performed. Seeds immersed up to they reach 15% of water with GA3 and immersed up to the water acquisition of 20% without GA3, presented higher soluble sugars levels and germination percentage, which were decreased when the seeds reached 30% and 35% of water, independently of the presence of the plant growth regulator. It was conclude that different water contents reached by the seeds in immersion treatments with GA3 affect the soluble sugars levels and germination percentage of Annona emarginata seeds. Thus, in treatments with Annona emarginata, the seeds must remain immersed in water without GA3 up to they reach 20% of water, as higher water contents (35%) reduce the soluble sugars levels and the seed germination percentage.