Influence of the ICDAS e-learning program for occlusal caries detection on dental students

The aim of this study was to evaluate the influence of ICDAS training in a group of dental students for occlusal caries detection in permanent teeth. Premolars and molars (N=104) with occlusal surfaces varying from ICDAS scores 0 to 6 were cleaned, one occlusal site per tooth was selected, and a photograph taken to identify the site. Eight senior dental students examined the teeth twice with a one-week interval between examinations during each of two phases: before and after the ICDAS e-learning program. Teeth were histologically assessed for caries extension. Intraclass correlation coefficients for intra- and interexaminer repeatability were high, both before (0.75 and 0.72, respectively) and after e-learning (0.82 and 0.78, respectively). The ICDAS scores decreased significantly from before to after e-learning (p=0.0001). Correlation between ICDAS scores and histology scores was moderate (0.57 before e-learning and 0.61 after). Although the ROC curve shows an improvement in the use of the ICDAS scoring after e-learning, the difference was not significant (p=0.10). Specificity of the ICDAS scores significantly improved after e-learning (77 percent vs. 36 percent), and sensitivity was reduced slightly after e-learning (87 percent vs. 92 percent). The ICDAS e-learning program improved the performance of the diagnostic skills of the investigated students for the detection of occlusal caries lesions.

Maternal obesity disturbs the postnatal development of gonocytes in the rat without impairment of testis structure at prepubertal age

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Establishing common elements among some science education references as a resource to design a Didactics of Physics program for teachers initial education

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of glass forming histories on the structural and thermal properties of tellurite glasses

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of Nb content on the corrosion resistance and saturation magnetic density of FeCuNbSiB alloys

Nanocrystalline FeCuNbSiB alloys obtained from the partial crystallization of amorphous alloys have attracted technological attention due to their excellent magnetic properties, but the relationship between corrosion resistance and magnetic properties is not well established. The influence of Nb as an alloying element and effect of partial crystallization on the corrosion resistance of Fe73.5Si13.5B10Cu1, Fe73.5Si13.5B7Nb3Cu1 and Fe73.5Si13.5B5Nb5Cu1 amorphous alloys were studied and the effect of corrosion on magnetization saturation flux density, B-s, was investigated. The addition of niobium on amorphous alloys increases the corrosion resistance. The raise of Nb content from 3 to 5% increases the corrosion resistance also. A partial crystallization increases the corrosion resistance of the samples with Nb. However, in the samples without Nb, the partial crystallization diminishes the corrosion resistance. The values of B-s depend on the alloy corrosion resistance.) (C) 2002 Elsevier B.V. B.V. All rights reserved.

Nothing too much: reflecting about the role of contextualization in science teaching

The contextualization and discussion about the science role in the social and economical development are unquestionably important for the science teaching process. It doesn't mean, however, that the scientific-theoretic knowledge and the strategies involved in its construction and application might be neglected. In this way, a dangerous situation is created when the contextualization is assumed as a unique and primordial target in science education. This paper presents a research carried out with 15 future chemistry teachers and the results show a worrying "supervalorization", of the contextualization beside other equally important aspects of the chemical knowledge.

Dietary vitamin or mineral mix removal during the finisher period on broiler chicken performance

The effect of dietary vitamin (VS) and mineral (MS) mix withdrawal between 42 and 49 d of age on broiler chicken performance was evaluated. The diets were formulated based on corn and soybean meal, and the experiments were conducted in floor pens using wood shavings as litter. Trial I evaluated withdrawal of VS and MS mix at 42, 45, and 49 d. The results of this trial showed that VS and MS mix withdrawal at 42 d of age did not impair feed intake (FI) or weight gain (WG), but feed conversion (FC) was improved (P = 0.043) when both mixes were maintained in the diets until 49 d of age. Trial 2 assessed the withdrawal of VS or MS mix at 42 d of age. FI and WG were not affected by withdrawal, but FC was poorer (P = 0.035) for the broilers fed the diet without VS. The relative liver weight was reduced by VS or MS mix withdrawal (P = 0.014 and P = 0.001, respectively). Carcass, breast, and leg yields were not affected by VS or MS mix withdrawals in either trial. The findings of the study suggested that VS mix withdrawal during the final period of broiler chicken growth was more deleterious than the withdrawal of MS mix, because it affected FC ratio. VS or MS withdrawal during this period did not affect carcass yield.

Use of reduced concentrations of tetrazolium solutions for the evaluation of the viability of peanut seed lots

The possibility of reducing the concentration of the working solution used in the tetrazolium test for peanut seeds (Arachis hypogaea L.) with or without seedcoats was studied. Tetrazolium solutions of different concentrations (0.05%, 0.075% and 0.1%) were tested at the temperatures of 35 and 40 degrees C, for determining the time needed for the seeds to reach proper staining. The efficiency of the selected treatments in evaluating the viability potential of the seeds was determined by comparing the results of the tetrazolium tests with those obtained by standard germination (using sand and rolled paper towel as substrata) and seedling emergence in the field tests. Staining the seeds without seedcoat in 0.05% tetrazolium solution for three hours at 40 degrees C yielded efficient results. on the other hand, reduced concentrations can be employed in the staining process of seeds with seedcoat; however, this method requires a higher consumption of tetrazolium salt, longer staining time as well as a higher ability and availability of time for embryo evaluation, since the cross-cutting of seeds is much more difficult in the presence of the seedcoat and the occurrence of damage to the outer surface of the cotyledons cannot be determined.

Periapical tissue healing after post space preparation with or without use of a protection plug and root canal exposure to the oral environment. Study in dogs

The purpose of this study was to evaluate the influence of coronal leakage on the healing of dogs' periapical tissues after root canal filling, post space preparation and protection or not with a temporary sealer plug. Forty root canals of dogs' teeth were instrumented and filled by the lateral condensation technique with gutta-percha points and Endomethasone or CRCS sealers. After post space preparation, the remaining filling material was protected or not with a plug of temporary Coltosol sealer and exposed to the oral environment for 90 days. Thereafter, the animals were sacrificed and the specimens were removed and prepared for histomorphological and histobacteriological analysis. The findings revealed 35% of microbial leakage in the groups without plugs and 15% of leakage in the groups with plugs. Statistical analysis showed that the use of a Coltosol plug improved significantly the histomorphological results regardless of the type of root canal sealer (p=0.05) and that CRCS and Endomethasone sealers showed similar results (p>0.05).

Timed artificial insemination programs during the summer in lactating dairy cows: Comparison of the 5-d Cosynch protocol with an estrogen/progesterone-based protocol

The objective of this study was to compare a GnRH-based to an estrogen/progesterone (E2/P4)-based protocol for estrous cycle synchronization and fixed timed artificial insemination (TAI), both designed for synchronization of ovulation and to reduce the period from follicular emergence until ovulation in cows with a synchronized follicular wave. A total of 1,190 lactating Holstein cows (primiparous: n = 685 and multiparous: n = 505) yielding 26.5 ± 0.30 kg of milk/d at 177 ± 5.02 d in milk were randomly assigned to receive one of the following programs: 5-d Cosynch protocol [d -8: controlled internal drug release (CIDR) + GnRH; d -3: CIDR removal + PGF2α; d -2: PGF2α; d 0: TAI + GnRH] or E2/P4 protocol (d -10: CIDR + estradiol benzoate; d -3: PGF2α; d -2: CIDR removal + estradiol cypionate; d 0: TAI). Rectal temperature and circulating progesterone (P4) were measured on d -3, -2, 0 (TAI), and 7. The estrous cycle was considered to be synchronized when P4 was ≥1.0 ng/mL on d 7 in cows that had luteolysis (P4 ≤0.4 ng/mL on d 0). To evaluate the effects of heat stress, cows were classified by number of heat stress events: 0, 1, and 2-or-more measurements of elevated body temperature (≥39.1°C). Pregnancy success (pregnancy per artificial insemination, P/AI) was determined at d 32 and 60 after TAI. The cows in the 5-d Cosynch protocol had increased circulating P4 at the time of PGF2α injection (2.66 ± 0.13 vs. 1.66 ± 0.13 ng/mL). The cows in the E2/P4 protocol were more likely to be detected in estrus (62.8 vs. 43.4%) compared with the cows in the 5-d Cosynch protocol, and expression of estrus improved P/AI in both treatments. The cows in the 5-d Cosynch protocol had greater percentage of synchronized estrous cycle (78.2%), compared with cows in the E2/P4 protocol (70.7%). On d 60, the E2/P4 protocol tended to improve P/AI (20.7 vs. 16.7%) and reduced pregnancy loss from 32 to 60 d (11.0 vs. 19.6%), compared with the 5-d Cosynch protocol. In cows with their estrous cycle synchronized, the E2/P4 protocol had greater P/AI (25.6 vs. 17.7%) on d 60 and lower pregnancy loss from 32 to 60 d (6.7 vs. 21.7%) compared with cows in the 5-d Cosynch protocol. Follicle diameter affected pregnancy loss from 32 to 60 d only in the cows in the 5-d Cosynch protocol, with smaller follicles resulting in greater pregnancy loss. Pregnancy per AI at d 60 was different between protocols in the cows with 2 or more measurements of heat stress (5-d Cosynch = 12.2% vs. E2/P4 = 22.8%), but not in the cows without or with 1 heat stress measurement. In conclusion, the 5-d Cosynch protocol apparently produced better estrous cycle synchronization than the E2/P4 protocol but did not improve P/AI. The potential explanation for these results is that increased E2 concentrations during the periovulatory period can improve pregnancy success and pregnancy maintenance, and this effect appears to be greatest in heat-stressed cows when circulating E2 may be reduced. © 2013 American Dairy Science Association.

Histopathological Changes by the Use of Soft Reline Materials: A Rat Model Study

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of calcium hydroxide addition on the physical and chemical properties of a calcium silicate-based sealer

Recently, various calcium silicate-based sealers have been introduced for use in root canal filling. The MTA Fillapex is one of these sealers, but some of its physicochemical properties are not in accordance with the ISO requirements. Objective: The aim of this study was to evaluate the flowability, pH level and calcium release of pure MTA Fillapex (MTAF) or containing 5% (MTAF5) or 10% (MTAF10) calcium hydroxide (CH), in weight, in comparison with AH Plus sealer. Material and Methods: The flowability test was performed according to the ISO 6876: 2001 requirements. For the pH level and calcium ion release analyses, the sealers were placed individually (n=10) in plastic tubes and immersed in deionized water. After 24 hours, 7 and 14 days, the water in which each specimen had been immersed was evaluated to determine the pH level changes and calcium released. Flowability, pH level and calcium release data were analyzed statistically by the ANOVA test (alpha=5%). Results: In relation to flowability: MTAF>AH Plus>MTAF5>MTAF10. In relation to the pH level, for 24 h: MTAF5=MTAF10=MTAF>AH Plus; for 7 and 14 days: MTAF5=MTAF10>MTAF>AH Plus. For the calcium release, for all periods: MTAF>MTAF5=MTAF10>AH Plus. Conclusions: The addition of 5% CH to the MTA Fillapex (in weight) is an alternative to reduce the high flowability presented by the sealer, without interfering in its alkalization potential.

The first Brazilian municipal initiative of payments for environmental services and its potential for soil conservation

It has become evident that policies aimed at mitigating the growing water resources and water use conflicts in Brazil are crucial. The municipality of Extrema in Minas Gerais state in Brazil pioneered the first Brazilian municipal PES initiative (Conservador das Aguas program), based on the relationship between forests and the benefits they provide. This study aimed to assess soil loss in the Posses sub-basin, where the Conservador das Aguas program began. Additionally, we aimed to determine the potential that this PES initiative has for soil conservation, as well as to minimize the soil losses as a function of forest area size and location in order to propose a technical approach for implementing PES. In this sense, considering the prescribed conservation practices, land use situation, and soil cover in the Posses sub-basin, we analyzed the effectiveness of the Conservador das Aguas program before and after implementation in relation to reduced soil loss under 36 different land use and soil cover scenarios. We used a geographic information system (GIS) for spatializing and producing different information plans and the Revised Universal Soil Loss Equation (RUSLE) for estimating soil loss. As a result, we found that minimization of soil loss may be obtained by adopting pasture conservation practices. Additionally the expected average soil loss in the Posses sub-basin under conditions of land use and soil cover, before and after implementing the water conservation program was 30.63 and 7.06 Mg ha(-1) year(-1), respectively. (C) 2014 Elsevier B.V. All rights reserved.

Influence of spacing in the upper lateral incisor area on the perception of smile esthetics among orthodontists and laypersons

Background: The aim of this study was to determine the perception of smile esthetics among orthodontists and laypeople with respect to the presence of diastemas in the upper lateral incisor in the mesial, distal, and both surfaces using an oblique smile analysis. Methods: Two standardized oblique photos of pleasant smiles from two white women were selected. Images were digitally altered to create diastemas in the lateral incisor, in 0.5-mm increments, in the mesial, distal, or both surfaces. Final images were randomly assembled in a photo album, which was given to 120 judgesd60 orthodontists and 60 laypersons. Each rater was asked to evaluate the attractiveness of the images on a visual analog scale. The data collected were submitted to statistical analysis by the means of one-way ANOVA with the Tukey post hoc test and the unpaired Student’s t test. Results: The most attractive smile was the one without spacing, and the presence of diastemas was considered unattractive by both groups of raters, following a pattern: the greater and the more mesially located, the more unattractive was the smile. Conclusions: The results of this study suggest that diastemas in the upper lateral incisor area were considered unattractive, following a pattern: the greater and the more mesially located, the more unattractive was the smile.

Hard machining, glaze firing and hydrofluoric acid etching: Do these procedures affect the flexural strength of a leucite glass-ceramic?

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)